Comunicata Scientiae

Production of cucumber cultivars according to the accumulated thermal sum

2022-02-21T15:12:30-03:00

Cucumber is a species appreciated in cooking, in addition to providing various nutrients for health. In view of this, it is important that research on its growth is carried out, prioritizing statistical analyzes that effectively demonstrate the results. The objective was to verify the differences by analyzing of the variance and nonlinear models, in addition to characterizing the production, early production and production rate of cultivars of cucumber using of nonlinear models. An experiment was carried out in a randomized block design (RBD), with three cultivars (‘Atlantico’, ‘Caipira’ and ‘Fuyu’) in six replications. Two types of analysis of variance were performed for the variable mass of cucumber fruits. In the first the RBD design was considered with three cultivars and six replications and in the second the RBD design was considered in a split subdivided over time (cultivars x harvests). Afterwards, the Logistic growth model was adjusted for the fruit mass variable as a function of accumulated thermal sum, and determination of the critical points of the model. The use of nonlinear models to evaluate experiments with cultures of multiple harvests has advantages in relation to anova and complementary tests. The cultivar ‘Fuyu’, has higher productivity compared to the cultivars ‘Atlantico’ and ‘Caipira’, in addition to presenting greater precocity and production rate. The adjustment of the logistic model and its critical points allowed to identify the production, precocity and production rate of the evaluated cultivars of the cucumber.

Growth and physicochemical characterization of cherry tomato under irrigation with saline water and nitrogen fertilization

2022-02-21T08:28:04-03:00

Saline water is an alternative to the low availability of high-quality water in semi-arid regions. However, although these water sources negatively affect most crops, their use allied to management practices aiming to mitigate the effects of salts has been increasingly studied, including nitrogen fertilization. From this perspective, this study aimed to evaluate the growth and physicochemical characterization of cherry tomato plants irrigated with saline water and nitrogen fertilization. The experiment was conducted under field conditions at the Center of Sciences and Agrifood Technology of the Federal University of Campina Grande in Pombal – PB, using a randomized block design arranged as a 5 × 5 factorial referring to five electrical conductivity levels of irrigation water - ECw (0.3, 1.3, 2.3, 3.3, and 4.3 dS m-1) and five nitrogen doses - ND (50, 75, 100, 125, and 150% of the N recommendation), with three replications. The nitrogen doses did not mitigate the effects of salt stress on plant height and stem diameter of cherry tomato. However, irrigation with the electrical conductivity of 3.3 dS m^-1increased the soluble solids of cherry tomato fruits.

Plant growth and yield of garlic (Allium sativum L.) under applications of liquid biofertilizers

2022-02-21T15:20:58-03:00

Garlic is a highly relevant vegetable crop from the food and medicinal point of view in the culture of different peoples around the world. The new discoveries of the active components present in the bulbs increase the demand and require that garlic’s production system meets the demands of the market in quantity and quality. The nutrition in vegetables is crucial for the production and protection of crops, and in the garlic crop it is usual practice to apply minerals via leaf application during the cycle. The use and benefits of organic sources associated with minerals in the garlic crop raise questions about the viability of the leaf application method in this crop. The objective of this study was to evaluate the effectiveness of biofertilizers containing humic acids applied via leaf application in the crop of garlic (Allium sativum) in relation to the control (absence of humic acid). There was no significant variation for the foliar application of biofertilizers for the development parameters (aerial part, root system and bulb formation) and garlic production classes. Biofertilizer 4 at the dose of 30 L ha^-1 stood out compared to the Biofertilizers 2 and 3 for total productivity. The use of foliar biofertilizers with organic components associated with minerals can be considered an interesting alternative for the cultivation of garlic, especially if evaluated in the long term and considering the global benefits to the cultivation system.

Germination of Aristolochia elegans Mast. seeds at different temperatures and concentrations of gibberellin

2022-02-21T15:19:03-03:00

Aristolochia elegans is a plant widely appreciated for its attractiveness, being used as an ornamental species.
However, information on the germination behavior of its seeds is scarce. Thus, the objective of the current work is to evaluate the germination of seeds of A. elegans under varying conditions of temperature and concentrations of gibberellin. The seeds were immersed in gibberellin solution at concentrations of 100, 200, and 300 mg L-1, before being sown on blotting paper and transferred to germinators at constant temperatures of 15, 20, 25, 30, and 35ºC. The percentage, speed index, mean time, and germination speed were evaluated. There was no interaction effect or isolated effect of gibberellin, only an isolated effect of temperature on all parameters evaluated. For germination, a maximum response was obtained at the estimated temperature of 29.14˚C, with 75% germination, and the minimum temperature was estimated at 16.9˚C. The mean germination speed increased with increases in temperature, up to a maximum of 29ºC, and at temperatures above this value, the speed decreased. It is concluded that the temperature of 29.4˚C leads to the best germination, while at temperatures below 16.9˚C, the estimated minimum temperature, there is no seed germination. In addition, there is no effect of gibberellin on germination when doses are applied between 100 and 300 mg L^-1.

Photochemical efficiency of cashew rootstocks under salt stress and foliar application of potassium silicate

2022-02-10T09:57:13-03:00

The cashew tree is one of the most economically important fruit trees in Brazil, especially in the Northeast region. However, abiotic factors such as the salinity of water and soils in this region stand out as a limiting factor for this crop, affecting all stages of development, as well as physiological and biochemical processes. Therefore, the use of products that mitigate such damage becomes necessary, with silicon and potassium as a viable alternative. Thus, the objective of this work was to evaluate the photochemical efficiency of cashew tree rootstock subjected to water salinity and foliar potassium silicate application. A randomized block design, distributed in a 5x5 factorial scheme, with four replications and two plants per plot, was used, the treatments being by conductivity of the irrigation water - CEa (0.3, 1, 1.7, 2.4 and 3.1 dS m-1) and potassium silicate concentrations (0, 250, 500, 750 and 1000 mg L-1) applied via the leaves. The salinity of irrigation water causes reductions in the photochemical efficiency of photosystem II and, consequently, in the photosynthetic apparatus of cashew plants, 70 days after sowing. The concentration of 250 mg L-1 of potassium silicate promotes an increase in the quantum yield of cashew plants under salt stress conditions.

Agronomic potential, pest resistance, and fruit quality in BC1F3 dwarf round tomato populations

2022-02-23T15:51:52-03:00

Combining broad pest resistance, high yield, and nutritional quality of fruit in the same hybrid is a challenge for round tomato breeders. Thus, development of a dwarf round tomato line for obtaining hybrids may be an excellent alternative for achieving such objectives. The aim of this study was to evaluate the agronomic potential, fruit quality, and pest resistance of BC₁F₃dwarf round tomato populations. We evaluated 13 treatments and 4 replications. Treatments consisted of 10 BC₁F₃dwarf populations originating from self-fertilization of dwarf populations selected in BC₁F₂, plus both parents (recurrent and donor) and a commercial hybrid. The traits evaluated were yield, number of fruit, mean weight, number of locules, shape, pulp thickness, longitudinal and transverse diameter of the fruit, precocity index, and soluble solids, β-carotene, lycopene, and acylsugar content. The data were analyzed through the means test. In general, there was an increase of up to 1035% in average fruit weight of the dwarf populations in relation to the donor parent. In addition, some dwarf populations had fruit with 49% more lycopene compared to the commercial hybrid, as well as greater acylsugar content in the leaves (273%). The UFU-DW22 dwarf population stood out with good agronomic potential, higher lycopene content in the fruit, and high acylsugar content, which provides pest resistance. To continue this research, a second backcross is suggested in order to obtain lines and, posteriorly, hybrids with round fruits and compact plants, pest resistance and nutritional quality of fruit.

The Agronomic efficiency of the inoculant FT10 (Trichoderma asperelloides) on four lettuce varieties

2022-01-22T16:45:17-03:00

The present study aimed to evaluate the agronomic efficiency of FT10 (Trichoderma asperelloides) on lettuce varieties development and productivity throughout the year. Four greenhouse experiments were carried out to verify the effect of three doses of the bio-product on plant growth and yield on loose-leaf, butterhead, iceberg and salad bowl cultivars. A randomized block design was used, with six replications. The treatments were: 1) control, 2) 30.0 x 10¹² CFU.ha^-1 of the commercial inoculant ICB Nutrisolo ® Trichoderma, 3) 5.0 x 10¹¹ CFU.ha^-1 of FT10 inoculant, 4) 10.0 x 10¹¹ CFU.ha^-1 of FT10, and 5) 15.0 x 10¹¹ CFU.ha^-1 of FT10. Plant dry weight and yield were evaluated 42 DAT. The data obtained were compared with Duncan's test. Significant increases in yield in up to 21% for loose-leaf and 16% for butterhead were observed with the dose of 15.0 x 10¹¹ CFU.ha^-1 and 22% for iceberg and salad bowl with the dose of 10.0 x 10¹¹ CFU.ha^-1 of FT10. It can be concluded that FT10 has the potential to promote plant growth and increase the productivity of lettuce cultivars if applied the appropriate dose of the product.

Eugenia uniflora L. seedling production by cutting: substrate, sazonality, auxine and rejuvenation methods

2022-02-21T15:17:13-03:00

Eugenia uniflora is a species that presents great phytochemical variability, due to its main form of propagation, the seminal, which makes the cultivation of this commercial crop unfeasible. Therefore, the objective of this work was to develop a protocol for vegetative propagation of Eugenia uniflora by stem cuttings. Substrates (Tropstrato®, vermiculite and sand), indolbutyric acid concentrations, rejuvenation methods (drastic pruning and minicutting) and harvesting times (winter, summer, autumn and winter) of the stems were compared. The highest rooting percentage and quality of the root system in cuttings were obtained when commercial substrate Tropstrato® and with some method of rejuvenation were used. The minicutting was more efficient, reaching almost 50% of rooting when collected in summer . Stem cuttings from plants that did not undergo any kind of rejuvenation, regardless of the time of collection, did not result in root formation. No anatomical changes were observed between cuttings from rejuvenated and non-rejuvenated plant material, indicating that the rhizogenic process did not occur in the cuttings originated from plants without rejuvenation because of biochemical and/or physiological reasons. The treatment of the stem cuttings with IBA did not result in increase of rooting, therefore the use of this plant regulator is not recommended.

Yield and postharvest quality of 'common' arrowroot plants subjected to biofertilization

2022-02-21T15:15:27-03:00

A araruta ( Maranta Arundinaceae L.) é uma hortaliça não convencional com grande potencial econômico, mas pouco conhecimento quanto à sua nutrição mineral. O objetivo deste trabalho foi avaliar a produtividade e a pós-colheita de araruta 'comum' submetida a diferentes fontes e doses de fertilizantes orgânicos. O experimento em parcelas subdivididas foi disposto em quatro blocos de duas parcelas principais, cada uma dividida em cinco subparcelas. As fontes de fertilizantes (esterco bovino e ovino) foram aplicadas nas parcelas principais, sendo cinco doses de cada fertilizante líquido (0; 300; 600; 900 e 1.200 mL planta ^-1 semana ^-1) foram aplicados às subparcelas. Número de rizomas (NR), massa fresca dos rizomas (FMR), massa seca dos rizomas (DMR), peso médio do rizoma (ARW), rendimento do rizoma (RY), comprimento do rizoma (RL) e diâmetro do rizoma (RD) foram medidos . Melhores resultados para RY, FMR e RL de plantas de araruta 'comum' foram observados para o biofertilizante bovino em comparação com o biofertilizante ovino. Doses de fertilizantes variando de 737 a 1.200 mL planta ^-1 semana ^-1 são recomendadas para maximizar o rendimento e a qualidade pós-colheita da araruta 'comum'. RY de 212,51 t ha ^-1 e 207,1 th ^-1 foram obtidos quando 1.200 mL planta ^-1 semana ^-1 de esterco bovino e ovino foram aplicados em plantas de araruta cultivadas em vasos, respectivamente.

Production and post-harvest quality of custard apple irrigated with saline water and fertilized with N-P-K

2022-02-21T15:23:29-03:00

Salt stress reduces plant growth and production. However, adequate fertilization can minimize the effects of salinity. From this perspective, this study aimed to assess the production and post-harvest quality of custard apple irrigated with saline water and fertilized with combinations of nitrogen, phosphorus, and potassium in the second year of cultivation. The experiment was conducted in a randomized block design and arranged as a 2 × 8 factorial with three replications, using containers adapted as drainage lysimeters in a protected environment in the municipality of Campina Grande, PB. The factors consisted of two levels of electrical conductivity of irrigation water - ECw (0.8 and 3.0 dS m^-1) and eight combinations of N-P-K fertilization: 100-100-100; 100-100-125; 100-125-100; 100-125-125; 125-100-100; 125-100-125; 125-125-100; and 125-125-125% of the recommended (100%) level (100-80-40 g of N-P2O5-K2O per plant per year). Irrigation with the water salinity level of 3.0 dS m^-1 reduced custard apple production in the second year. However, fertilization with the 125-100-125% N-P-K combination increased the mean fruit weight, total soluble solids, and ascorbic acid content. High irrigation water salinity negatively affected the number of segments, number of fruits, number of seeds per plant, mean fruit weight, fruit diameter, and fruit height. The 125-100-40 g N-P-K combination provided the highest values of mean fruit weight, total soluble solids, ascorbic acid content, and maturity index regardless of the salinity level. The plants grown under the ECw of 0.8 dS m-1 and 125-100-80 g of N-P-K achieved the highest total production per plant.

Postharvest control of anthracnose in avocado with cassava starch and corn starch films

2022-02-21T15:09:26-03:00

The objective of this study was to evaluate the effect of cassava starch and corn starch films on the control of anthracnose in avocado. The fruits were inoculated with conidia suspension and were then immersed in solutions with cassava starch and corn starch alone or in combination at concentrations of 1, 2, 3 and 4% under curative and preventive methods. The variables analysed included mean damaged area, area under the disease progress curve (AUDPC) and fruit fresh weight. Under the curative method, the mean damaged area and AUDPC were reduced in fruits treated with 1% and 4% cassava starch and 1% corn starch. Under the preventive method, fruits treated with 2% cassava starch or 2% corn starch alone resulted in reduced mean damaged area and AUDPC. The combinations of cassava starch and corn starch at 2, 3, and 4% were effective in reducing the mean damaged area and AUDPC under curative control. Under the preventive method, the combinations of cassava starch and corn starch at 2 and 3% reduced the AUDPC, and the mean damaged area was decreased with both starches at 3%. Scanning electron microscopy images revealed a layer of protective film on the fruit's surface that probably prevented the pathogen from penetrating. In addition, there was deformation of hyphae promoted by the action of the films.

Production of Talisia esculenta seedlings under irrigation with saline water in substrate with hydrogel

2022-02-21T15:05:05-03:00

Salinity is one of the factors that compromise the formation of seedlings, so it is necessary to associate measures that mitigate its effects. The objective of this study was to evaluate the effects of irrigation frequencies, water salinity, polymer and container volume on the growth and quality of Talisia esculenta (A. St.-Hil.)Radlk seedlings.
The treatments were obtained from the combination of polymer concentrations (0.0; 0.2; 0.6; 1.0 and 1.2 g
dm-3), electrical conductivities of water (0.3; 1.1; 2.7; 4.3 and 5.0 dS m-1) and irrigation frequencies (daily and alternate) plus two additional treatments to evaluate container volume. The growth and quality of seedlings were analyzed at 100 days after sowing. Reduction in irrigation frequency from daily to alternate days reduced the growth, biomass accumulation, and quality of the seedlings. Overall, salinity hampered the formation of the seedlings while the polymer had positive effects. T. esculenta seedlings are considered to be sensitive to salinity
and should be irrigated using water with conductivity of up to 0.7 dS m-1 at a daily frequency of application. The polymer can be incorporated up to 1.2 g dm-3 and containers with higher volumetric capacity (0.75 vs 1.30 dm3) are indicated for the production of T. esculenta seedlings.

Development of chia plants in field conditions at different sowing-date

2022-02-09T17:06:18-03:00

The objective of this study was to characterize the development of chia plants sown at different dates, and to determine the relation between the duration of the development cycle and the final number of leaves and the leaf appearance rate on the main stem. A field experiment was conducted in the agricultural year of 2016/2017 in five sowing dates (09/22/16, 10/28/16, 01/03/17, 02/08/17 and 03/24/17) in the edaphoclimatic conditions of the central region of the RS, Brazil. A randomized block design with four replicates was used. For each sowing date, the duration of the vegetative and reproductive phases in days and in °C day (Tb = 11 °C), the final number of leaves and the phyllochron of the main stem were determined. The duration of the vegetative phase of chia plants in days and in ºC day varies between the sowing dates, with shorter duration in late sowings in response to the photoperiod reduction. The vegetative phase represents the largest part of the total development cycle in early sowing dates, being overcome by the reproductive phase in late sowing dates (02/08/17 and 03/24/17). The phyllochron for chia varies from 36.23 (very late sowing) to 59.88 ºC day (early sowing). Later sowing has a smaller final number of leaves accumulated in the main stem due to the shorter duration of the vegetative phase.

Estimation of Thunbergia grandiflora leaf area from allometric models

2022-02-21T10:24:49-03:00

Sky vine (Thunbergia grandiflora Roxb) is a vine with important structural components for forest environments. Studies on growth and development are necessary, because of the environmental and economic importance. The leaf area determination is essential for ecophysiological studies to understand the relationship of the plant with the environment. The objective of this work was to estimate an allometric equation to estimate the leaf area of T. grandiflora from linear dimensions. 200 leaves of different shapes and sizes were collected from adult plants and the length (L), width (W), the product between length and width (LW), and real leaf area (LA) were measured. The linear regression, linear without intercept, quadratic, cubic, power, and exponential models were used to estimate the equations. The criteria for determining the best model were higher determination coefficient (R²), Willmott's agreement index (d), lower Akaike information criterion (AIC), the root of the mean error square (RMSE), and BIAS index closer to zero. The leaf area of T. grandiflora can be estimated satisfactorily by the equation ŷ = 0.58*LW.

Vitoria pineapple yield predictions by neuro-fuzzy modeling and linear regression

2022-01-22T16:42:45-03:00

Hybrid intelligent systems that combine artificial intelligence techniques, such as neural networks and fuzzy logic, have become common for the development of complex models to predict and estimate variable parameters. The objective of this study was to compare predictions of Vitoria pineapple yields by Adaptive-Network-Based Fuzzy Inference Systems (ANFIS) and linear or quadratic regression models. The prediction models developed calculate the fruit fresh weight based on the D leaf fresh weight (DLFW) and stem diameter (SD), measured at the time of floral induction. ANFIS were developed using the genfisOptions function of the Neuro Fuzzy Designer toolbox of the Matlab program (Mathworks®- Neuro Fuzzy Designer, R2018a), considering DLFW and SD as the entry parameters, single and combined. The yield prediction error was calculated using the root mean square error (RMSE). The RMSE found for all ANFIS developed were lower than that predicted by linear or quadratic regression models. The lowest RMSE was obtained when the parameters DLFW and SD were combined for the development of the ANFIS. Therefore, the results showed that the use of neuro-fuzzy modeling (ANFIS) for predicting Vitoria pineapple yield presents better results than the use of linear or quadratic regression models.

Performance of pine cone seedlings in different doses of phosphate fertilizing

2022-01-22T17:53:14-03:00

Adding phosphorus in the composition of the substrate for the seedlings production contributes to a faster growth of seedlings, increases the resistance to biotic and abiotic stresses, also improves the efficiency in the use of nutrients and water in many vegetal species. The objective of this research was to evaluate the vegetative growth and quality of Annona squamosa L. seedlings, propagated by seeds, regarding the application of single superphosphate in enriched sugarcane bagasse substrate. The completely randomized design consisted of six treatments arranged according to the following application doses (0; 0.75; 1.5; 2.25; 3.0 and 3.75 kg), using the single superphosphate in substrate, with four replicates per treatment. At 120 days after sowing, number of leaves, leaf area, shoot height, stem diameter, shoot dry mass, root dry mass, total dry mass, ratio between shoot dry mass and root dry mass, chlorophyll a, chlorophyll b, total chlorophyll, and Dickson’s Quality Index were evaluated. The maximum growth of the pine cone plants were noted when added single superphosphate to the substrate in doses ranging from 0.6 to 1.2 kg.m^-3. The phosphate fertilizer favored the growth especially of the roots and leaf area and improved the quality of pine cone seedlings.

Agricultural ambience and salt stress in production of yellow passion fruit seedlings

2021-10-04T11:00:36-03:00

The objective was to evaluate the initial growth and gas exchange of yellow passion fruit seedlings irrigated with saline water under different environments. The experiment was conducted of the University of International Integration of Afro-Brazilian Lusophony, Redenção-CE. The experimental design used was entirely randomized, in factor arrangement 4 x 2, referring to four environments with different shade screens (black screen; white
screen; red screen; all with 50% shading; and full sun) and the values of electrical conductivity of irrigation
water (0.3 and 3.0 dS m-1), with five repetitions. The following variables were evaluated: number of leaves, plant height, leaf area, photosynthesis, transpiration, stomach conductance, instantaneous water use efficiency, electrical conductivity of the saturation extract and soil pH. The environment with black screen provides greater performance in leaf area, plant height and root length and was more efficient for the production of dry mass of the aerial part and the root of passion fruit seedlings in both irrigation waters. The red screen environment stimulates greater photosynthesis, transpiration, stomach conductance and chlorophyll in passion fruit seedlings irrigated with low salinity water, while the black screen mitigated saline stress for these variables. The full sun environment provided greater instantaneous water use efficiency in passion fruit seedlings for treatment with low salinity water and the black screen environment with high salinity water.

Physiological changes of bell pepper grown under nutrient solutions prepared with brackish water and H2O2 concentrations

2022-02-16T16:32:08-03:00

The adoption of strategies to mitigate the negative effects of excess salts in irrigation water is essential for maintaining productive systems, especially in semiarid regions. The objective was to evaluate the gas exchange and chloroplast pigments of hydroponic bell pepper under combinations of water (saline and rain) and exogenous application of hydrogen peroxide (H₂O₂). The experiment was developed in a protected environment belonging to the Agricultural Engineering Academic Unit, in a completely randomized experimental design, with treatments arranged in a 4 x 3 factorial scheme, with 5 replications, consisting of the mixture between brackish water (BW) and rain water (RW): C1 = 10% BW + 90% RW; C2 = 20% BW + 80% RW; C3 = 30% BW + 70% RW; C4 = 40% BW + 60% RW) and three concentrations of hydrogen peroxide (H₂O₂) [0.0 (control); 7.5 µM and 15 µM]. The application of 15.0 μM H₂O₂ in bell pepper plants cultivated with nutrient solution in the combinations 30% SW + 70% RW and 40% BW + 60% RW between brackish water and rainwater promoted an increase in photosynthesis 24 days after the sowing while. At 61 days after sowing, the highest values of gs and E of bell pepper grown with nutritive solution in the combinations 10% BW + 90% RW were obtained with the application of 15.0 μM H₂O₂. The levels of chlorophyll “a”, “b”, total and carotenoids in bell pepper had the deleterious effects caused by the salinity of the nutrient solution mitigated by the exogenous application of hydrogen peroxide at a concentration of 15 μM.

Hydrogen peroxide as a mitigator of salt stress for melon seed germination

2022-02-21T15:25:26-03:00

The effect of hydrogen peroxide has been very studied, but little is known on its effect on seed germination and initial growth of melon trees under salt stress. In this context, the objective of this work was to evaluate the effect of hydrogen peroxide as a mitigator of salt stress on melon seed germination. The experiment was conducted in the Laboratory of Seeds and Seedlings of the Federal University of Campina Grande, in Pombal, PB, Brazil. A completely randomized design was used, in a 4×6 factorial arrangement consisting of times of seed imbibition in H2O2 (0, 8, 16, and 24 hours) and irrigation water salinity levels (0.3, 1.2, 2.1, 3.0, 3.9, and 4.8 dS m-1), with four replications. Melon seeds of the commercial variety Imperial-45 were used. The H2O2 solution was prepared from a 1 mmol L^-1 H2O2 solution, which was diluted to reach the concentration of 10 μmol L^-1. The seeds were placed in a beaker and subjected to imbibition with 100 ml of the solution for the different times studied. The variables evaluated were: germination percentage, first germination counting, germination speed index, mean germination speed, mean germination time, and radicle length. The of H2O2 solution to seeds for 16 hours mitigates the negative effects caused by salt stresses by up to 2.2 dS m^-1; however, the application of H2O2 solution for 24 hours is harmful to the germination process of melon seeds.

Physical-Chemical characteristics of alternative substrates and fertilization on the growth and quality of Spondias macrocarpa seedlings

2022-02-21T15:27:51-03:00

The objectives were to determine the physical and chemical characteristics of different substrates, and assess the influence of different substrates, with and without the addition of controlled-release fertilizer, on the growth and morphological quality of taperebá (Spondias macrocarpa) seedlings. The experimental design adopted was a 2 x 6 factorial scheme, with the presence and absence of 8.0 g L^-1 of encapsulated controlled-release fertilizer and six substrates [Sub1= soil; Sub2= soil + carbonized rice husk (2:1 v/v); Sub3= soil + organic compos (2:1 v/v); Sub4= soil + carbonized rice husk + organic compost (1:1:1); Sub5= soil + carbonized rice husk + organic compost (2:1:1); Sub 6= soil + carbonized rice husk + organic compost (2:2:1)], with five replicates, composed of 10 seedlings (one in each container). Formulations of substrates containing soil + carbonized rice husk + organic compost (1:1:1) and soil + organic compost (2:1 v/v) had total porosity ranging from 0.88 to 0.91 m³ m^-3, aeration space from 0.33 to 0.35 m³ m^-3 and available water from 0.27 to 0.29 m³ m^-3, hence being suitable to obtain taperebá seedlings with superior quality. The substrate Cerrado soil (Sub1) is not viable for the production of taperebá seedlings, since it has acidic pH, an undesirable chemical characteristic for the cultivation of this species. Incorporation of controlled-release fertilizer into the substrates used in the present study led to better morphological characteristics, so it is indicated as an input for fertilization in the initial stage of growth of taperebá seedlings.

Vermiculite and shading in the formation of 'Rangpur' lime rootstock

2022-02-21T15:30:56-03:00

‘Rangpur’ lime (Citrus limonia Osbeck cv. Cravo) is widely used as a rootstock for citrus seedlings, although factors such as luminosity and substrate composition are extremely important to obtain quality seedlings. The objective of this study was to analyze the formation of ‘Rangpur’ lime seedlings grown in different substrates and luminosities. A 3x4 factorial arrangement was used in an RBD with four replications of twelve plants. Three luminosities (full sun, 35%, and 70% shading) and four substrate: vermiculite proportions were tested (S1-1: 0, S2-2: 1, S3-1: 2, and S4-0: 1). The seeds were sown in 280 cm³ tubes and emergence was evaluated every two days for 30 days, and biometric assessments at 30, 60, 90, and 120 DAE by measuring the height, diameter, leaves, and mortality. Root length and shoot and root dry mass were measured at 30 and 120 days. Seeds in full sun showed high ESI values and a shorter time period, as well as high mortality at 120 DAE. Highly shaded environments cause etiolation and reduce biomass accumulation and the DQI. Seeds in S4 showed lower results for most variables. It is recommended to use 35% shading associated with the substrate proportions S1, S2, and S3.

Organic fertilization in top dressing in jambu production

2022-02-21T15:32:58-03:00

In the state of São Paulo, jambu has been grown with a view to its industrial uses. However, there are few works involving mineral nutrition and organic fertilization in jambu, which leads farmers to use fertilizer recommendations intended for other similar leafy crops and several different fertilizers. Thus, the objective of this study is to evaluate different sources of organic fertilizers in top dressing in the production of jambu under organic management.
The experiments were carried out at the Experimental Farm of São Manuel, SP, and at the Zodíaco farm, located in the Demétria district, Botucatu, SP. Six treatments (organic fertilizers in top dressing: ferticel®, provaso, castor bean cake, bokashi, hoof and horn powder, and a control without top dressing) were evaluated, using a randomized block design with five replicates. From two harvests in each location, the following characteristics were evaluated: the fresh weight of vegetative parts (FWVP) and of inflorescences (FWI), the total fresh weight (TFW), the number of inflorescences (NI), and the average weight per inflorescence (AWI). The results show an increase of 158% and 78%; 103 and 101%; 143 and 86%; and 144 and 85%, in FWVP, FWI, NI, and TFW, respectively, with the use of hoof and horn powder (the best treatment, not differing from castor bean cake) compared to the control at Zodíaco farm and at the Experimental Farm of São Manuel, respectively. These results indicate that hoof and horn powder and castor bean cake were the best fertilizers in both harvests and locations, with higher production of both fresh and dry weight of the vegetative and reproductive parts of jambu.

Determining the preliminary performance of selected Annonaceae cultivars in subtropical conditions

2021-11-11T11:25:39-03:00

Plants phenology is extremely important tool for crop management, crop manipulation, and marketing. The objective of this research was to investigate the phenology and fruit quality of the several Annonaceae species under subtropical conditions of Homestead, Florida, USA. The study was carried out in an experimental sugar apple (Annona squamosa L.), orchard with cultivars: 'LeahReese', 'Lessard Thai' and 'Red' and the atemoya ‘Gefner’ (A. cherimola x A. squamosa L). Ten uniformly vigorous and healthy plants of each cultivar were selected. The fruit harvest period was similar for all the cultivars, except for sugar-apple 'LeahReese', which had the shortest harvest period of only 41 days. Multivariate analysis showed that 'Lessard Thai' and 'Red' sugar apple cultivars had smaller sizes and lower chemical quality. Cultivar "LeahResse" had the highest fruits, in addition, a strong correlation with the atemoya hybrid "Gefner". The sugar apples ‘Lessard Thai’ and 'Red' had similar phenology and had a 166-day pruning to harvest cycle. In contrast, 'LeahReese' sugar apple and 'Gefner' atemoya had significantly longer cycles of 182 and 196 days, respectively. The sugar apple 'LeahReese' had the best physical characteristics of the cultivars investigated, while the atemoya 'Gefner' had the best physiochemical characteristics and the longest shelf life.

Dispersion of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) in kale and cabbage fields

2021-11-22T08:21:07-03:00

Parasitoids of the Trichogramma genus are used worldwide for pest management. The ability to disperse these insects in crops determines the number of release points necessary for there to be satisfactory results in terms of parasitism and, consequently, pest management. To determine the dispersal capacity of T. pretiosum in cabbage and cabbage crops, 26 x 26 m areas were demarcated, in which cards containing A. kuehniella eggs were placed, distributed in a concentric and equidistant manner. In the center of each area, 100,000 parasitoids were released and parasitism was allowed for 24 hours. The experimental design used was in randomized blocks, with five treatments (distance) and four replications. The average dispersed distance was 6.27 meters in cabbage and 6.07 in cabbage, while the dispersion area was 81.23 in cabbage cultivation and 79.03 meters in cabbage cultivation. 123 release points required for kale and 126 for cabbage.

Hedge and central pruning in a high-density pecan orchard in southern Brazil

2022-02-20T11:42:24-03:00

This study aimed at evaluating the influence of two pruning methods, as well as absence of pruning, on vegetative and productive development and in the quality of pecan fruits in a high-density orchard. The experiment was conducted with the cultivar Melhorada in a commercial pecan orchard in municipality of Santa Rosa, Rio Grande do Sul (RS), Brazil. The study was carried out between July 2018 and June 2020. In a randomized block design, the following treatments were applied: no pruning, hedge pruning and central pruning. Hedge pruning increased limb growth, while central pruning decreased the number of dry branches. Fruit production oscillated in the cycles. In the first, production was higher when central pruning was conducted. In the second cycle, it was higher in unpruned trees. Even though both pruning methods decreased the number of fruit with closed epicarps, they did not affect most variables of fruit quality. Therefore, results show that pruning methods promote vegetative development of pecan trees, reducing dry branches, but they are inconclusive regarding their production and have no significant effect on the main variables of their fruit quality. The evaluation and continuity of pruning for more cycles is important to obtain the most consistent results for indicating the best alternative for producers.

Bell pepper germination and seedling’s parameters under different osmotic potentials

2022-02-25T08:26:29-03:00

Bell pepper (Capsicum annuum L.) is the third most cultivated Solanaceae species in Brazil and is highly sensitive to osmotic stresses. The increasing soil salinity is a frequent problem that hinders the plant absorption of water and nutrients by the roots, limiting agricultural production. Therefore, this study’s objectives were to evaluate the germination, vigor, and development of bell pepper commercial cultivars after NaCl treatments to simulate osmotic stress. Five cultivars (Yolo wonder, SF134 yellow, Marta, All big red, Cascadura) were submitted to four osmotic potentials (salt stresses of 0, -0.3, -0.6, -0.9 MPa) in a factorial scheme of 5×4, with four repetitions. The results indicated that the bell pepper germination is highly affected according to the presence of NaCl. The bell pepper germination supports NaCl concentrations equal to or higher than -0.3 MPa osmotic potential. Significant reductions in germination, germination speed index, seedling length, and dry mass as the salinity increases - osmotic potential decrease. The yellow bell pepper ‘SF134’ presented similar germination down to -0.6 MPa and can be cultivated in regions with salinity problems. The green bell pepper ‘Cascadura’ presented great germination, germination speed index and dry mass, and superior seedling length, being indicated for cultivation in more diverse environments.

Application timing affects the selectivity of herbicides for garlic crops

2022-02-21T14:08:19-03:00

Chemical control is the main weed control method in garlic crops; however, this crop is sensitive to herbicides, which can cause injuries and decrease yield depending on the products used, application timing, rate, and cultivar. In this context, the objective of this study was to evaluate the selectivity of herbicides for garlic plants (cultivar Chonan), using different application timings. A greenhouse experiment was conducted in a completely randomized design with four replications. An 8×2 factorial arrangement was used, in which the first factor consisted of a control without herbicide and seven herbicides (linuron, diuron, pendimethalin, s-metolachlor, oxyfluorfen, flumioxazin, and oxadiazon) applied according to the second factor, application timings (preemergence or post-emergence). Phytotoxicity, photosynthetic rate, stomata morphometry, bulb diameter, and crop yield of garlic were evaluated. Pre-emergence applications were more selective than post emergence applications. The herbicides linuron, diuron, s-metolachlor, and oxadiazon applied at pre-emergence, and s-metolachlor, oxyfluorfen, flumioxazin, and oxadiazon applied at post-emergence were not selective for the Chonan garlic cultivar. Pendimethalin presented the highest selectivity, regardless of the application timing. Oxyfluorfen and flumioxazin applied at pre-emergence and linuron and diuron applied at post-emergence were selective for the cultivar Chonan.

Macro and micronutrient accumulation in watermelon

2022-02-07T16:31:35-03:00

The expansion of crop productivity such as watermelon can be reached by providing adequate nutrition in quantity and when plants need it most. It is known that well-nourished plants better resist biotic and abiotic stresses, being determinants for more sustainable management. In this sense, the objective of the present study was to evaluate the plant growth, the rate of nutrient absorption, the proportion of absorption, and estimate the quantity of exported nutrients by watermelon fruits. The experiment was implemented in randomized block design with eight treatments (phenological phases) - 33 and 40 (growth), 47 and 54 (flowering), 61 and 68 (filling), 75 and 82 (maturation) days after planting (DAP). Each evaluation consisted of plant collection for dry mass, macro, and micronutrient analysis in the shoot (leaves and stems), fruits, and the entire plant. The period between 61 and 68 DAP was the one with the highest plant dry matter increment. The accumulation of macronutrients in the plant shoot showed the following decreasing order: Ca>N>K>Mg>P>S, in the fruits: K>N>P>Ca>Mg>S and in the whole plant: K>N>Ca>P>Mg>S. For micronutrients, the decreasing order of accumulation for the shoot and the entire plant were Fe>Mn>Zn>B>Cu, and for fruits were Fe>B>Zn>Mn>Cu.

Artificial Diets for Rearing of Ceratitis capitata (Wiedemann 1824) (Diptera: Tephritidae)

2022-02-25T16:49:13-03:00

Ceratitis capitata (Wiedemann 1824)(Diptera: Tephritidae) is a polyphagous insect responsible for severe damage to fruit production worldwide. Control strategies require laboratory studies in which large numbers of individuals of this pest are required, thus requiring the implementation of mass creations. The success of these creations depends on the use of artificial diets, which represent one of the main costs of this system. In this sense, this study aimed to evaluate the efficiency of different artificial diets based on regional foods in the development of C. capitata in the laboratory. Eggs of C. capitata were inoculated in artificial diets based on sweet potato, yam, carrot, pumpkin and cassava, all in the raw and cooked version, totaling ten treatments, with raw carrot being the control treatment. Variables related to the biometric and biological characteristics of C. capitata, such as larval and pupal viability, fecundity, fertility and sex ratio, in addition to pre-oviposition, oviposition and adult life times, were evaluated. Promising results were obtained with the use of artificial diets based on regional foods, such as sweet potato and pumpkin, in which higher pupae weight and size, good fecundity and fertility, insects with longer oviposition time and longer longevity were observed, whose results were similar or superior to those obtained with the raw carrot-based diet. In contrast, the raw cassava-based diet did not allow larvae to hatch. Unsatisfactory results were also obtained with diets based on yam, both raw and cooked, which makes its recommendation for use in artificial diets for this insect unfeasible. Artificial diets derived from pumpkin and sweet potato, raw or cooked, are efficient as carrot substitutes in artificial diets of C. capitata.

UV-C radiation in the post-harvest quality of red pitaia

2022-02-09T15:59:01-03:00

The cultivation of pitaya in Brazil is growing and the increase in consumption is associated with the nutritional benefits and attractiveness of the fruit. However, information about the post-harvest behavior of the fruits, in relation to their conservation potential and technologies, is incipient. In this aspect, the objective was to evaluate the postharvest quality of red pitaya submitted to different doses of UV-C radiation. The fruits were acquired from the commercial orchard in the rural area of Piracanjuba-GO. The experiment was carried out in a completely randomized design, in a 4x9 factorial scheme, with four radiation doses (0; 1.81; 3.62 and 7.24 kJ m^-2) and nine days of analysis (0, 2, 4, 6, 8, 10, 12, 14 and 16 days). After radiation, the fruits were placed in low density polyethylene packages (LDPE), with 1 fruit in each, being refrigerated and stored in an incubator type B.O.D. at 8±1°C, with 60±4% RH. The following were evaluated: mass loss, post-harvest conservation, soluble solids content, pH, titratable acidity, maturation index, color (°Hue, Chroma), betacyanins and carotenoids. Data were submitted to analysis of variance (P<0.05) and, when significant, regression analysis was performed. The dose of 1.81 kJ m^-2 stood out in maintaining the quality of the red pitaya fruit. Pitaya treated or not with UV-C radiation, packaged in LDPE, can be kept refrigerated for up to 21 days without deteriorating.

Production and selection of accessions of Opuntia spp. with resistance to false carmine cochineal

2022-02-21T14:06:47-03:00

The genetic improvement program for Opuntia spp. aims to select new genotypes to meet the demands of rural producers in the Brazilian Semiarid region and to expand the genetic base of the crop. The aim of this study was to select accessions of Opuntia spp. with foraging potential and resistance to false cochineal carmine. The research was carried out at the Active Germplasm Bank (BAG) of Opuntia spp. of Paraíba Company Research, Rural Extension and Land Regularization (EMPAER), Pendência Experimental Station, Soledade, Paraíba, Brazil. Accessions were cultivated in rainfed and evaluated in August 2019, 12 months after the implementation of the BAG. The measurement of the Total Green Mass weight of the plants of 121 accessions of the BAG was carried out and the productivity (ton/ha^-1) was estimated in a dense cultivation of 100 thousand plants/ha^-1. The accessions of Opuntia spp. nº 10, 110, 115 and 119 have growing potential in the Brazilian Semiarid region, as a function of productivity (532.6, 118, 164 and 481 tons/ha^-1, respectively) and resistance to false carmine cochineal, in addition to genetic divergence (specific agronomic characteristics) in relation to currently cultivated varieties.

New substrate medium mixture can improve the initial growth of Hylocereus costaricensis (Haw)

2022-02-16T16:42:39-03:00

Dragon fruit is an exotic species that has currently shown great relevance in the world market. Hence, the demand for materials with high genetic potential has increased. Genetic propagation allows selecting materials with high yield and climatic conditions adaptation. The selection of the substrate influences the quality of the seedling, which should provide adequate conditions for germination and root development. This study aimed to evaluate the seed emergence and initial growth of dragon fruit cultivated in different substrates under nursery conditions. The experiment was carried out in a completely randomized design, with 11 treatments, four replications, and 25 seeds per replication. The treatments used were composed of the soil, mixture with organic compost and commercial substrate. First emergence count, emergence percentage, and emergence speed were evaluated up to 50 days after sowing. Data of shoot length, stem diameter, root length, shoot dry matter, and root dry matter were recorded at 88 days after emergence. The treatment of washed sand + coconut fiber and Tropstrato^® provided a higher emergence percentage and emergence speed of dragon fruit seeds. The treatment of coconut fiber + Tropstrato^®+ organic compost allowed better means for stem diameter, shoot dry matter, and root dry matter. Conversely, the treatments of washed sand + Tropstrato^® and Tropstrato^® resulted in greater root system growth.

March of nutrient absorption and growth of fertigated melon ‘Gladial®’

2022-02-21T08:22:15-03:00

The use of fertigation in melon cultivation is becoming increasingly common, and there is a need to optimize the doses of applied fertilizers. Knowledge of the nutritional demands of the crop and its rate of uptake is essential for determining the amount of nutrients required at different phenological stages. The objective of this study was to determine the rate of macronutrient and micronutri ent uptake in fertigated melons, as well as the accumulation of fresh and dry matter in leaves, stems, and fruits. This study was performed in Petrolina-PE, in an entirely randomized experimental design with nine evaluation periods and six repetitions. Plants were collected at 7, 14, 21, 28, 36, 43, 50, 57, and 64 days after emergence (DAE). The accumulation of N, P, K, Ca, Mg, Fe,
Mn, Zn, Cu, dry matter, and fresh matter in the leaves, stems, fruits, and total matter accumulation throughout the cycle was analyzed. Dry matter increases at 64 DAE. Nutrient accumulation was in the following order of micronutrients: K>Ca>N>Mg>P and Fe>Mn>Zn>Cu.

Quality of cookies with partial substitution of wheat flour for okra flour

2022-02-21T14:10:32-03:00

Okra is a vegetable of high nutritional value, but highly perishable when stored in natura. Cookies are products of great popular acceptance and allow the use of alternative flours. The objective was to evaluate cookies made with partial substitution of wheat flour for okra. Okra fruits were dried to obtain the flour. This was applied in biscuit formulations at concentrations of 0 (A), 5 (B), 10 (C) and 15% (D). The cookies were evaluated for the difference in mass, thermal factor, yield, humidity, ash, fibers, proteins, lipids, carbohydrates, caloric value, presence of Coliforms at 45 ° C, positive coagulase Staphylococcus and Samonella sp., In addition to the sensory evaluation acceptance and purchase intention. The dough, ash content, fiber and protein of the cookies enriched with okra flour were higher. The carbohydrate content and caloric value was higher in formulation A. All cookies are within the microbiological standards required by law. Sensory acceptance and purchase intention were superior in formulations A and B. The differences between the cookies are due to the different composition of the okra and vary according to the concentration in which it is added. Formulation B obtained better nutritional quality without interfering with its good sensory acceptance.

Growth and quality of passion fruit seedlings under salt stress and foliar application of H2O2

2022-02-27T17:22:50-03:00

Passion fruit is a species with high production potential under the climatic conditions of the Brazilian
Northeast region. However, water sources in this region show high salt concentrations that can compromise
crop development. In this scenario, the application of small hydrogen peroxide concentrations reduces the
deleterious effects caused by salt stress on the production yield of agricultural crops. From this perspective,
this study aimed to evaluate the growth and quality of yellow passion fruit seedlings irrigated with saline water
and foliar application of hydrogen peroxide. The experiment was conducted in a plant nursery at the Federal
University of Campina Grande, PB. The experimental design was in randomized blocks in a 5 x 2 factorial.
Treatments consisted of five levels of electrical conductivity of the irrigation water - ECw (0.6, 1.2, 1.8, 2.4, and
3.0 dS m-1) and two concentrations of hydrogen peroxide - H2O2 (0 and 20 μM), with four replications and two
plants per plot, totaling 80 plants. The exogenous application of 20 μM hydrogen peroxide favored plant growth
in stem diameter, plant height, number of leaves, and the Dickson Quality Index of the passion fruit cv. BRS Rubi
do Cerrado. The application of 20 μM hydrogen peroxide induced the acclimatization of the passion fruit cv.
BRS Rubi do Cerrado irrigated with saline water.

Physiological and sanitary attributes of organic lettuce seeds treated with essential oils during storage

2021-12-15T21:07:36-03:00

The use of quality seeds becomes crucial in the seed production system. In the production of organic seeds, there is a need for specific techniques. Therefore, the objective of this work was to evaluate the applications of clove, lemongrass, rosemary, eucalyptus, ginger and tea tree essential oils in different concentrations of lettuce seeds. Seed quality was determined by physical (water content), physiological (germination and vigor) and sanitary parameters, immediately after the application of essential oils and after 180 days of storage. The design was completely randomized in a factorial scheme (6x5) with four replications. The application of rosemary, ginger and tea tree essential oils to the seeds shortly after harvest did not interfere with germination. The other essential oils resulted in reduced germination and vigor. Increasing the concentration of essential oils, especially clove and lemongrass, reduced germination, vigor and incidence of fungi. It was concluded that Clove, Lemongrass, eucalyptus, ginger, Rosemary and tea tree essential oils reduced the physiological quality of lettuce seeds and inhibited the development of Alternaria sp. lettuce.

Irrigation water salinity and silicon negatively interfere with the physiology and delay the flowering of ornamental sunflowers

2022-02-02T16:46:38-03:00

Although silicon is considered a non-essential element for plants, its application can mitigate the harmful effects of salt stress. In this sense, the objective was to evaluate the physiological and flowering responses of ornamental
sunflower depending on the application of silicon and irrigation with saline water. The experiment was carried out in a greenhouse in a completely randomized design with six replications, in a 4 x 5 factorial scheme, referring to four electrical conductivities of irrigation water (ECw): 0.5; 1.5; 2.5 and 3.5 dS m-1 and silicon doses: 0, 50, 100, 150 and 200 mg L-1, with potassium silicate as the source. The following were evaluated: internal carbon concentration, transpiration, rate of liquid photosynthesis, instant efficiency of carboxylation, leaf indexes of chlorophyll a, b, chlorophyll a/b ratio, total chlorophyll, external and internal diameter of the chapter, number of petals, appearance of floral bud, beginning of flowering and full opening of the floral bud. Salinity negatively affects photosynthetic activity and flowering of ornamental sunflower plants, so that plants irrigated with saline water (3.5 dS m-1) delayed the appearance of the flower bud, the flowering index and the total opening of the floral button. The application of silicon in ornamental sunflower plants is not effective to mitigate the deleterious effects of salinity on the plant’s physiology. In addition, the addition of silicon is also not able to repair the losses in terms of flowering caused by salt stress in the species.

Relationship between physicochemical characteristics and gene expression in lettuce as a tool for genetic improvement

2022-02-06T10:47:04-03:00

Alface ( Lactuca sativa L.) is a leafy vegetable worldwide consumed. It is found in its constitution vitamins and minerals, as well as bioactive compounds, such as phenolic compounds, flavonoids and anthocyanins. Since anthocyanins are responsible for the red color of the leaves and in the body prevents the appearance of non-communicable chronic diseases by the fight against free radicals. The lettuce for being present in the diet of the population becomes a promising plant for biofortification with the selection of plants with high levels of anthocyanins. The objective of the present work was to study the quantitative distribution of anthocyanin in leaves of lettuce plants of a segregating F2 population obtained from the initial crossing between two color contrasting parents (green and red).. The color, anthocyanin and flavonoid contents, as well as color correlation with anthocyanin content and the heritability of these characteristics. It was concluded that the anthocyanin content in leaves of lettuce is controlled by more than one gene with partial dominance of the genes that confer higher levels. Intense red coloration can be used as an alternative in lettuce breeding programs to identify superior lettuce genotypes with high anthocyanin content. Transgressive segregation as well as the higher heritability values observed in the studied traits will allow selecting in segregating generations, superior genotypes in accordance with the proposed objectives.

Technical feasibility of minicutting of different portions of the branch to produce clonal seedlings of Aloysia citrodora

2022-02-28T15:20:20-03:00

Seedling production using the minicutting technique enables quick and efficient plants formation. However, there are no reports of application for Aloysia citrodora (lemon verbena) and the ideal portion of the branch. This study aimed to evaluate the production of seedlings from minicuttings taken from different parts of the branch.
The experiment was performed in a completely randomized design. Three treatments consisted of minicuttings taken from other branch portions (basal, median, and apical), divided into two experiments (Exp1 and Exp2).
Exp1 was carried out in a sub-irrigation system in phenolic foam, evaluating rooting percentage, length of the longest root, root number, number of shoots, number of leaves, and total dry mass. Exp2 used the minicuttings from the previous experiment, kept for another 35 days in pots to assess the quality of the seedlings, evaluating plant length, number of shoots, and leaves. For Exp1, 35 days after cutting, there was a higher percentage of survival, size of the longest root, number of the root, number of shoots, number of leaves, and total dry mass, in those minicuttings produced from the basal and median portions, being the exact behavior of Exp2, 35 days after transplantation to pots. The minicutting proved to be an efficient method for producing Aloysia citrodora
seedlings, when removed from the basal or median portion, standing out for a higher percentage of survival, better growth, and initial development and post-transplantation of the produced seedlings.

Jambolão extract and potassium sorbate as antimicrobial components in active packaging

2022-02-21T10:01:13-03:00

This study aimed to use the raw extract of jambolão (Syzygium cumini L.) and potassium sorbate as antimicrobial components in cellulose acetate films and evaluate their potential for application as active packaging forsugar-free banana preserve. The films were prepared using the casting method and evaluated for thickness and inhibition potential. The efficiency of the films as active packaging, in situ, was evaluated through the enumeration of aerobic mesophiles and mold and yeast over 36 days of storage of banana preserves.
Furthermore, in order to analyze the fungicidal effect of the films against banana preserve with an initial load of microorganisms, mold and yeast were counted for 25 days of storage. The results showed that the incorporation of crude jambolão extract increased the film thickness, and its inhibition potential was similar to the film with incorporated potassium sorbate. Furthermore, the film with crude jambolão extract reduced mold and yeast growth by up to 1 log cycle over 36 days of storage. Furthermore, the use of the film with potassium sorbate promoted the same effect as this preservative added directly to the fruit preserve and proved to be efficient even with relevant initial contamination. Thus, the use of these active packagings presents an opportunity for industries as they reduce health risks and improve the safety and quality of preserves.

Outcrossing and heterozygosity rates in tropical onion populations

2021-06-08T10:24:32-03:00

Outcrossing and heterogosity rates are important for defining genetic conservation and breeding strategies, and these estimates are quite rare to onion. The aim of this study was to estimate cross-pollination and heterozygosity rates in tropical onion populations to guide development of new varieties. Eight tropical onion pairs were field isolated to be open pollination by insects. Parents vernalized bulbs were used for pair crossing, in alternate rows, 1:1. Seeds were harvested from the female parent to assess the progenies outcrossing and heterogigosity rates based on color of the red bulb, partially dominant over yellow, and four microsatellite loci. The outcrossing rates estimated with morphological marker, in the ‘BRS Rio Vale’ × ‘BRS Carrancas’, ‘Botucatu’ × ‘BRS Carrancas’, ‘IPA 11’ × ‘IPA 10’ and ‘BRS Alfa São Francisco’ × ‘IPA10’ crosses, ranged from 15% to 39%, with an average of 28.2%, while with microsatellite loci, in the ‘BRS Alfa São Francisco’×’IPA 11’, ‘Alfa SF RT’ × ‘BRS A. São Francisco’, ‘BRS Rio Vale’ × ‘Botucatu’ and ‘Cascuda T6’ × ‘Botucatu’ crosses, ranged from 33% to 71%, with an average of 42.7%, indicating a mixture of cross-pollination and self-pollination within progenies. The average values of heterozygosity in the eight populations ranged from 0.82 to 1.0, indicating the possibility of developing open pollinated onion varieties with greater adaptation to biotic and abiotic stresses.

Diaspores biometry, temperatures and light regime on seed germination of Ptychosperma macarthurii (Arecaceae)

2022-02-25T14:13:34-03:00

This work aimed to analyze diaspores biometric characteristics, the effect of different temperatures and light regimes on seed germination and on the initial seedlings’ growth of Ptychosperma macarthurii. The experiment was performed at the Horticulture Seed Laboratory, UNESP/FCAV, Jaboticabal, SP. The individual diaspores biometric analysis was performed by measuring the length, diameter, mass and weight of a thousand diaspores, the data were subjected to descriptive statistical analysis. It was adopted a completely randomized design in a 5 × 2 factorial with four replications of 25 seeds per treatment. Five temperatures (25; 30; 35; 20-30 and 25-35 ºC) and two light regimes (presence and total absence of light) were evaluated. The variables analyzed were germination, germination speed index, average length of the primary root and shoot, diameter of the stem and seedlings total dry mass. The length, diameter and average weight of the diaspores were 12.54 mm, 6.05 mm and 0.1610 g, respectively. The seeds of Ptychosperma macarthurii germinated in a wide temperature range, reaching a higher germination percentage at 25 ºC and a higher germination speed index at 30 ºC, being classified as neutral photoblastics. The constant temperature of 30 ºC provided higher mean values for all seedlings’ biometric characteristics.

Physical and fruit region characterization of araticum and seed germination as a result of accesses

2022-02-16T16:29:13-03:00

The physical characteristics of the fruits are of great importance for the identification and selection of superior genetic materials, appropriate for commercialization or industrial use. Given the above, the objective was to physically characterize the araticum fruit and to verify the influence of accessions and fruit region under seed germination. The work was developed at Unioeste, Marechal Cândido Rondon Campus (PR), and conducted at the University Laboratory of Post-Harvest Technology. Ripe fruits of araticum (Annona sylvatica) were collected from four native plants (accessions A1, A 2, A3, and A4) at the Experimental Farm of the University in February 2019. As for the physical evaluation of the fruits, four repetitions of 10 randomly chosen ripe fruits per access were evaluated. The longitudinal diameter, transversal diameter, fruit biomass, epicarp biomass, fruit pulp, number of seeds, and mass of 100 seeds were the characteristics evaluated. The experimental design used for the germination test was completely randomized, in a factorial scheme 4 x 2 [4 accessions (A1, A2, A3, and A4) x 2 regions of the fruit (proximal and distal) in 500 mg L-1 of acid gibberellic (GA3)], containing 4 repetitions and 25 seeds per repetition. The evaluations were carried out from the 15th day of the experiment setup until 105 days. The characteristics evaluated were: first germination count (%), germination percentage (%), germination speed index, and average germination time (days). The fruits had an average biomass of 63.41 g, an average of 38 seeds per fruit, and fruit pulp with an average of 39.63 g. The germination of araticum seeds was not influenced by the accessions and fruit region.

Physiological factors in the production of cabbage under no-tillage

2022-02-07T13:13:40-03:00

The no-till system promotes benefits that extend not only the characteristics of soil improvement, interfering in the quality and productivity of the plants, thus improving physical, chemical, and biological attributes of the crop and resulting in profitability to the producer. The present study evaluated the agronomic development of cabbage according to different cover plants. The experiment was performed in the field, in the Vegetable sector of the University of Rio Verde - UniRV, Rio Verde, GO. The cover plants used were millet (Pennisetum americanum (L)), sunflower (Helianthus annuus), brachiaria (Brachiaria decumbens), and crotalaria (Crotalaria juncea). The studied greeneries were cabbage (Brassica oleracea), Astrus plus hybrid. The parameters evaluated to analyze the physiological development were: the plants’ height, number of leaves, and cabbage diameter. The results were submitted to the descriptive statistical method with analysis of means, covariances, and correlations, using the Matlab program. Plant growth data were submitted to the analysis of variance, and when significant, the cover plant factor was compared by Fisher’s test, and the factor days after planting was analyzed by regression. The cabbage showed a higher mean height (cm), leaves, and diameter with the sunflower covering plant. The millet was the best plant to increase the cabbage’s mean productivity.

Physiological and metabolic responses in broccoli plants fertilized with green manure

2022-03-02T10:23:41-03:00

Grasses and legumes affect differently the amount of N in the soil over time, mainly due to the differences in the chemical characteristics of its mass. Changes in the availability of N influence the absorption and assimilation of N, which will influence physiological processes in the plants. The objective of this paper is to evaluate the changes in gas exchange, chlorophyll fluorescence and biochemical activity in leaves of broccoli grown under different green manure amendments. The experiment was designed in a complete randomized block design, using the mass of jack bean (JB) and millet (M) pure and in mixtures and one control, totaling six treatments: Control, 100JB, 75JB25M, 50JB50M, 25JB75M, 100M, with four replicates. The canopy area, N content, gas exchange, and biochemical analyzes were evaluated on the broccoli index leaf 40 days after broccoli transplantation. The higher ratio of jack bean, the higher the canopy area, the N content and the amino acid, protein and malate content, and lower starch content, possibly due to the higher N mineralization in this green manure.

Eucalyptus shading and allelopathy in the germination and development of pitaya (Hylocereusundatus)

2022-02-08T09:00:24-03:00

Eucalyptus spp. it is known to be part of most forests planted for commercial use in Brazil, however when intercropped with Pitaia (Hylocereus undatus), few studies report this interaction. The objective of this work was to evaluate the effects of shading and the existence of allelopathic interaction between Eucalyptus spp and pitaia (H. undatus) in the field, as well as the action of eucalyptus leaf extract in the germination of pitaia seeds in laboratory conditions. In the field experiment, the statistical model of randomized block design (DBC) was used, with the use of adult plants of pitaia and eucalyptus, evaluating the following variables: number of shoots in the aerial part; number of flowers; crown diameter; circumference of the cladode; number of fruits and the variation in the amount of light reaching the plants. It was observed that the plants that were outside the eucalyptus forest showed better results. In the second experiment, the allelopathic action of different concentrations of aqueous extracts of eucalyptus leaves on the germination of pitaia seeds was evaluated. This experiment was carried out in DIC with four repetitions of 60 pitaia seeds. These seeds were then subjected to treatments with different dilutions, varying from 0% (control), 12.5%, 25% and 50% of the stock solution. It was observed that as the leaf extract concentrations increased, germination decreased. The concentrations of 0% (control) and 12.5% showed better results. In conclusion, in fact, eucalyptus exerted an allelopathic action on pitaia plants.

A contribution to the physicochemical characterization of Eugenia involucrata DC. fruits to estimate genetic variability

2022-02-22T21:30:27-03:00

Brazil has one of the greatest diversities in native fruit trees, but many species, despite the great environmental and economic potential for small farms, are little studied, such as the cherry-of-the-rio-grande (Eugenia involucrata DC.). The hypothesis of this research was that there is a high genetic diversity due to the propagation by seeds, occurring genotypes that produce better quality fruits which can be used to implement genetic improvement programs and the production of seedlings with better productive performance. So, this study aimed to characterize fruits of this species' genotypes and to evaluate the genetic divergence applying multivariate analysis techniques. Genotypes of different ages found in rural and urban areas of the municipality of Serafina Corrêa, Rio Grande do Sul, were evaluated, with 50 genotypes in 2018 and 38 genotypes in 2019, since twelve did not bear fruit. Data were submitted to determine the mean and standard deviation. To assess genetic diversity, the relative contribution of characters was determined by the Singh method; the average Euclidean distance standardized matrix (UPGMA) and dendrograms were generated; and Tocher's optimization method was applied. Results showed that UPGMA and Tocher clustering methods are more efficient in representing the diversity between genotypes. Fruits characteristics varied from one year to another, due to the combination of biotic and abiotic factors (water regime), resulting in changes of characters with greater contribution in the divergence and formation of similar groups. The content of total soluble solids (TSS) in 2018 and fruit mass in 2019 harvest were characters that most contributed to the genetic divergence. It was concluded that the physicochemical characters of fruits revealed the existence of genetic divergence among genotypes, allowing the selection of agronomically superior plants.

Base temperature and plastochron are influenced by the development phase in biquinho pepper cultivars

2021-09-13T21:18:07-03:00

The objective was to estimate the base temperature and determine the plastochron for Capsicum chinense cultivars during the vegetative and reproductive development phases at different planting times. The experiment was conducted in a randomized block design, 2x4 factorial scheme, cultivars of biquinho pepper (“BRS Moema”, “Airatema Biquinho Amarela”) and growing seasons (E1-E2-E3-E4). The Air temperature was monitored during the vegetative and reproductive phases of the crop. Tb was determined by the minimum mean square error method (QMe). For both phases of the crop development, plastochron was determined by linear regression between the number of nodes and the accumulated thermal sum (Sta). Tb and plastochron were not influenced by the cultivar. In the vegetative phase, Tb and plastochron were dependent on the sowing season, presenting on average Tb (16.8°C) and plastochron (43.6°C day^-1). In the reproductive phase both Tb and plastochron were similar at all sowing times, with averages of 16.7°C and 64.4°C day^-1 plastochron, for base temperature and plastochron, respectively. Therefore, the emission of nodes is not influenced by the cultivar, but by growing season. With the plastochron values found it is concluded that the development of biquinho pepper is more accelerated during the vegetative phase than the reproductive one.

Mechanical properties of pumpkin seeds

2022-02-07T09:58:37-03:00

Due to the lack of information on the mechanical properties of pumpkin seeds and the need to develop equipment that can be used more efficiently for its processing, the objective of this project was to study the mechanical properties of commercial pumpkin seeds. Pumpkin seeds (Cucurbita moschata) from the commercial cultivars ‘Rajada Seca Melhorada’ and ‘Jacarezinho’ with moisture content ranging from 0.670 to 0.094 decimal dry basis (db) and 0.923 to 0.033 decimal (db), respectively, were used. The determination of the compressive strength of the seeds was carried out by means of uniaxial compression tests. The seeds were compressed in their natural resting position, at a constant speed (force application rate) of 0.0001 m s^-1. The average force for deformations in the 'Rajada Seca Melhorada' was 43.90 and 0.56 N and for 'Jacarezinho' between 13.20 and 0.20 N, and the values of the proportional deformity module from 8.05 to 23.68 x 10⁷ N m^-2 cultivar 'Rajada Seca Melhorada' and 2.05 to 21.64 x 10⁷ N m^-2 for 'Jacarezinho'. It is concluded that the necessary force for deformation of pumpkin seeds decreases with the increase of the moisture content. There is an increase in the values of the proportional deformity module with the reduction of the moisture content, for the cultivar ‘Rajada Seca Melhorada’ and ‘Jacarezinho’. It can be seen that the seeds of the pumpkin 'Rajada Seca Melhorada' have a greater resistance to the deformation force in relation to 'Jacarezinho'.

Phenotypic plasticity of Aloysia citrodora: anatomical changes to water availability and seasons

2022-01-24T09:40:27-03:00

The objective was to evaluate the anatomical changes of the leaves of Aloysia citrodora submitted to different water availability during the seasons. The experiment was conducted in a greenhouse, in a randomized block design, bifactorial 4x4, with four seasonal factors (autumn, winter, spring, and summer) and simulations of water availability (25, 50, 75 and 100% of field capacity) with four repetitions. They were evaluated in μm: the thickness of the adaxial and abaxial cuticles, adaxial and abaxial epidermis, palisade and lacunous parenchyma, mesophyll and leaf thickness of the transversal section and the mesophyll and thickness of the main rib and the length and width of the vascular system. In the autumn season, there was a reduction in the width of the vascular system and the thickness of the adaxial cuticle under greater water availability. In winter and under low water availability, there was a reduction in the thickness of the cuticle and adaxial epidermis, lacunous parenchyma, mesophyll and leaf thickness, mesophyll and main rib thickness. In the spring with greater water availability increased in the adaxial and abaxial epidermis, mesophyll and thickness of the main rib, and length of the vascular system; and low water availability provided the greater thickness of the adaxial cuticle, palisade parenchyma, and leaf thickness. In the summer season with the greatest water availability, there was an increase in leaf thickness and adaxial cuticle and a reduction in palisade parenchyma, while low water availability increased the thickness of leaf mesophyll.

Nutrient omission on growth and leaf contents of blackberry

2021-12-15T15:07:09-03:00

Cultivation of blackberry has gradually expanded in Brazil, due to their rusticity and low production cost; thus, it stands out as an excellent option for product diversification. There is a need to improve technical information on the management of this crop, especially mineral nutrition. Knowledge of the visual symptoms of nutritional deficiency and foliar contents of the nutrients allows helps farmers to choose the most adequate fertilization for plants. This study aimed at evaluating nutritional aspects and effects of nutrient omission on the growth of BRS Xingu blackberry. Treatments consisted of complete solutions and individual omission of the following nutrients: nitrogen (N), phosphorus (P), potassium (K), calcium (C), magnesium (Mg), boron (B), manganese (Mn), zinc (Zn) and iron (Fe). The following variables were evaluated: leaf dry matter, root dry matter, total dry mass, macro- and micronutrients contents in leaves and visual symptoms of nutrient deficiency. Macronutrient and B deficiencies limit growth of blackberry. B omission led to the highest decrease in plant growth, besides leaf wrinkling, a fact that shows that BRS Xingu is susceptible to its deficiency. Correlation was found between N and Ca, N and P and B and Ca leaf contents. Low leaf contents of N, K, Ca and B were observed when these nutrients were omitted from the solution.

Double-phase culture medium and growth regulators in the micropropagation of blackberries

2022-02-28T18:25:18-03:00

Micropropagation is a technique that consists of producing disease-free and genetically uniform in vitro plants, which are produced in a shorter period of time than conventional propagation methods. The purpose of this study was to evaluate the effect of the consistency of the culture medium and the concentrations of BAP on the multiplication of sprouts, and concentrations of IBA on in vitro rooting of the Ébano and Tupy blackberry cultivars. The experiments were divided into three parts: In the first stage, culture media with solid, liquid, and double-phase texture were evaluated aiming at selecting the best culture medium in relation to quantity and quality of the sprouts. In the second stage, BAP concentrations were analyzed aiming at increasing the quantity of sprouts. In the third stage, IBA concentrations were evaluated aiming at optimizing root formation in the cultivars. The double-phase and liquid culture did not differ in the number of sprouts and leaves per explant and length of sprouts. The highest multiplication of sprouts on double-phase medium occurred with 5 μM L^-1BAP. Rooting was stimulated with the use of IBA and the best concentration was estimated at 1.1 μM IBA. The
multiplication of Ébano and Tupy cultivars can be carried out in double-phase MS medium with 5 μM L^-1 BAP and rooting in MS medium with 1.1 μM L^-1 IBA.

Precision agriculture tools for liming management in mango orchards in the Brazilian semiarid region

2022-02-21T10:06:35-03:00

Optimizing the recommendation for the management of Liming Demand (LD) is essential for cost reduction and increased yield mango. Therefore, the objective of this study was to delimit management zones for the limestone recommendation in areas of irrigated mango in the Brazilian semiarid using precision agriculture techniques. The experiment was carried out in three commercial mango orchards located in the region of the San Francisco Valley, Brazil. Soil samples were collected in 0.0-0.2 m and 0.2-0.4 m depths following regular grids where the number of samples varied from 50 to 56. Soil analyses were performed. The kriging and inverse distance weighting method were used to interpolated the maps. The LD map was performed from the potential cation exchange capacity (T) and bases saturation (BS) maps. It was verified that the Mandacaru area obtained 63.42% of the field requiring liming, being subdivided into four management zones. The Sempre Verde area obtained 1.20% of the area requiring liming and the Barreiro de Santa Fé area did not present a need for the LD map. The use of precision farming techniques to delineate management zones was adequate to separate the areas into smaller and more homogeneous zones, for a more precise recommendation of liming demand.

Joint application of fungicide and rhizobacteria on tomato seeds

2022-02-07T21:01:59-03:00

Tomato (Lycopersicon esculentum) is a vegetable that stands out among the others for being one of the most consumed and industrialized. Among the technologies for increasing crop productivity, the treatment of seeds with fungicides and or rhizobacteria that promotes plant growth stands out. The objective of the work was to evaluate the effect of the combined application of fungicide and rhizobacteria on the germination and vigor of tomato seeds. The assays were mounted in DIC in a factorial scheme 10 x 2 + 1 (10 rhizobacteria, with or without fungicide and additional treatment: fungicide only), with four replications. The following characteristics were evaluated: water content, germination, first germination count, germination speed index (IVG), seedling emergence and accelerated aging. In general, the treatment of seeds with rhizobacteria stimulates the physiological quality of tomato seeds. The rhizobacteria Paenibacillus lentimorbus-69 and Bacillus subtilis-34 proved to be compatible with the fungicide, favoring the germination and vigor of the seeds in relation to the treatment with fungicide

Performance of colored pepper cultivars under different concentrations of nutrient solution

2022-02-07T22:02:00-03:00

Knowledge on the nutritional requirement of the crop under cultivation systems adapted to local realities,
in addition to the adequate availability of nutrients in nutrient solution, is of fundamental importance both
for plant growth and for the production of quality fruits. Thus, the objective of this study was to evaluate the production performance of colored bell pepper cultivars in an open hydroponic system under different concentrations of nutrient solution. The experiment was carried out in a greenhouse at IFAL, Piranhas Campus, in a completely randomized experimental design with four replicates and in split plots, with plots containing three concentrations of nutrient solution (75%, 100% and 125%) and subplots containing three bell pepper cultivars (All Big, Sucesso and Beti-R). Concentration of nutrients at 75% of the standard nutrient solution differed from the other concentrations for plant height, stem diameter, leaf area and fresh and dry mass of the plant. The total number of fruits and number of marketable fruits were higher in the Beti-R and Sucesso hybrids when subjected to concentrations of 75% and 100%, respectively. The total yields of the Beti-R and Sucesso hybrids were higher at
the concentration of 75%, with maximum values of 24.19 t ha^-1 and 17.11 t ha^-1, respectively. The concentration of 100% of the standard solution promoted higher results for the All Big cultivar.

Genetic control of plant size-related traits and fruit in ornamental pepper (Capsicum annuum L.)

2021-12-16T16:01:48-03:00

Peppers present a very diversified market and have a high economic and nutritional value. The study of genetic control of quantitative traits helps to conduct an efficient breeding program. This study aimed to estimate the genetic parameters and gene effects involved in the inheritance of morpho-agronomic traits in ornamental pepper (Capsicum annuum L.). The experiment was carried out in a greenhouse, at the Plant Biotechnology Laboratory, at the Federal University of Paraíba. Two accessions of ornamental pepper (C. annuum L.) belonging to the vegetable germplasm bank of the Federal University of Paraíba were used as parents: UFPB 347 and UFPB 356. The experimental design was completely randomized, with five plants of each parent being evaluated, 20 plants of generation F₁, 90 plants of generation F₂ and 40 plants of RC₁ and RC₂. Foram avaliados 19 caracteres quantitativos referentes à planta, flor e fruto. Os dados obtidos foram submetidos à análise de geração, e os efeitos dos modelos foram submetidos ao teste t no nível de 5% e 1% de significância. Alta herdabilidade em sentido amplo foi encontrada para comprimento da corola, diâmetro das pétalas, peso do fruto, comprimento do fruto e espessura do pericarpo. Para herdabilidade restrita, apenas o comprimento da corola apresentou herdabilidade alta. O modelo aditivo-dominante (m, a, d) foi adequado para explicar os parâmetros genéticos da maioria das características avaliadas, com exceção do comprimento da antera e do teor de matéria seca, para os quais o modelo completo foi interpretado.

Palavras-chave: Capsicum annuum , análise de geração, herança.

Growth and mineral nutrition of banana seedlings cv. Grand Naine inoculated with arbuscular mycorrhizal fungi

2021-11-22T08:18:01-03:00

This study aimed to verify the influence of FMAs on the levels of macro and micronutrients, and growth of micropropagated banana seedlings submitted to doses of P. The experimental design adopted was randomized blocks, in a 5 x 5 factorial arrangement, with factors inoculation with AMFs (G. clarum, G. margarita, G. albida and C. etunicatum and the control without AMF) and P doses (0, 50, 100, 200 and 400 mg kg-1). The association of different species of FMAs can favor the growth of banana seedlings, with greater nutrition. The application of P doses provided greater growth of the micropropagated banana seedlings, regardless of inoculation with AMF. Seedling production associated with G. margarita can favor the growth of plants submitted to low doses of P applied to the soil. The interaction of G. clarum with Musa spp. seedling production does not seem to favor plant growth. Mycorrhizal colonization together with phosphate fertilization contributed to the quality of banana seedlings. The inoculation with C. etunicatum favored the increase of K contents in the aerial part of the plants. The increase in P doses decreased the levels of N and S in all treatments. It caused a reduction in the leaf contents of Mn, B and Fe. The doses of P did not interfere in the leaf contents of Cu and Zn. The FMAs favored the levels of Cu, Zn, Mn and B in banana leaves; favored the increments of Cu, Fe, Zn and Mn contents in banana seedlings, varying with the doses of P.

Production of Acalypha wilkesiana seedlings using stem cuttings

2022-02-27T23:31:30-03:00

The objective of this work was to evaluate the rooting of cuttings of Acalifa (Acalypha Wilkesiana) with different concentrations of indolbutyric acid (IBA). The matrix plant from which the cuttings were taken, is planted as a hedge and located at the biology institute of the Federal Rural University of Rio de Janeiro in the city of Seropédica-RJ. The experimental design was completely randomized, in a 3x3 factorial, with three different concentrations of IBA (0, 1000 and 2000 mg L^-1or 0, 2000 and 4000 mg L^-1 for 15 seconds) and three types of cuttings (herbaceous, semi-woody and woody), with three replications and ten cuttings per plot. The experiments were carried out at two different times, namely: autumn and winter / spring. The following were evaluated: percentage of live cuttings, rooted, with callus and sprouting, number of roots per cut, length of the largest root. Acalypha wilkesiana can be propagated by stem cuttings, whether woody, semi-woody or herbaceous cuttings. However, herbaceous cuttings have a lower percentage of survival and rooting. Also, is a species of easy rooting through cutting of stems, dispensing with the use of AIB. Stems collected in the autumn period yield greater efficiency and productivity in the propagation of cuttings by cuttings.

Sources and rates of organic substrates in the production of pear Cascatense on quince ‘CP’

2022-02-28T08:58:48-03:00

The nutritional state of cultivated plants can be influenced, due to the poultry litter doses and basalt powder, thus affecting its proper growth. This work aimed to evaluate the nutritional efficiency of pear, cultivated in different poultry litter doses and basalt powder. The experiment was conducted in the orchard of the fruit growing sector of the Department of Agronomy at the Universidade Estadual do Centro-Oeste, Guarapuava- PR, in 2010, spaced 2.5 x 0.5 m, with the following treatments in the planting hole and reapplied in August of 2012: T1) without fertilization; T2) 2 kg of poultry litter; T3) 2 kg of poultry litter + 2 kg of basalt powder; T4) 4 kg of poultry litter; T5) 4 kg of poultry litter + 2 kg of basalt powder. Samples of the root system, and the shoot segmented in side branches and trunk were collected in January / 2014 (1,190 days) for chemical analysis of nutrient content and dry matter. With these results were calculated the indexes: absorption efficiency; transport efficiency and nutrient utilization efficiency. The treatment 4 kg of poultry litter, result in a higher absorption efficiency ratio for N, and higher utilization efficiency index for S. The transport efficiency suffered a little variation due to the used doses.

Chemical thinning of peach trees

2021-10-19T09:34:42-03:00

Peach tree thinning is essential to harvest quality fruits and to keep balanced production for several years. Manual thinning of peach trees demands much work force and increases production costs. Chemical thinning may be an alternative solution, but efficiency depends on doses and species. This study aimed at evaluating the effect of metamitron – applied at different concentrations – on chemical thinning of peach trees in the south of Brazil. The experiment was carried out in a commercial peach tree orchard where ‘Sensação’ cultivars, in Morro Redondo, Rio Grande do Sul (RS) state, Brazil. The following metamitron concentrations were applied at concentrations of 100 mg L^-1, 200 mg L^-1, 300 mg L^-1, 400 mg L^-1, manual thinning was carried out 40 days after full bloom (DAFB) and to the treatment where the plants have no thinning. Fruit abscission, effective fructification, total number of plants per plant, production per plant, mean mass and fruit diameter were evaluated. Concentrations of 300 and 400 mg L^-1metamitron 40 DAFB provides promoted high fruit abscission, besides decreasing the number of fruits and production. Therefore, concentrations of 100 and 200 mg L^-1 of metamitron 40 DAFB provides results in an efficient thinning practice similar to manual thinning for production, mass and fruit diameter.

Foliar application of titanium on potato crop

2022-02-22T14:19:17-03:00

Although titanium (Ti) is not considered a nutrient, researches demonstrate that Ti leaf application can provide beneficial effects on plants growth. The objective of this study was to evaluate the influence of foliar applications of Ti levels on the metabolism, nutrient uptake and yield of potato crop, Agate cultivar. The experiment was conducted in a randomized complete block design with five treatments and four replications. The treatments were composed of 0, 10.2, 15.3, 20.4 and 22.9 g Ti ha^-1, divided into three applications during the growth stage, tuberization stage and tuber filling stage. Foliar applications of Ti increase the chlorophyll content (Spad value) in the tuber filling stage. Ti levels do not interfere with N, Zn and Cu nutrient accumulation. Increasing Ti levels linearly reduce the Mn, lipid peroxidation (PL) and urease content and increase the activity of peroxidase (POD), nitrate reductase (ANR), catalase (CAT), proline and Fe content in the growth stage, with maximum level around 3 to 6 g Ti ha^-1. In the tuberization stage, at high levels of Ti, there is an increase in urease activity and CAT while ANR has its lowest value. In the tuber filling stage, high Ti levels are related to high Fe, Mn, high ANR and superoxide dismutase (SOD) activity and low PL activity. The ideal level of titanium applied by leaf for greater yield of tubers is 11.3 g of Ti ha^-1.

Harvest interval for phytomass production of peppermint transplanted in summer and winter

2022-02-23T17:47:03-03:00

The objective of this study was to determine the appropriate harvest interval for the phytomass production of peppermint (Mentha x piperita L.) transplanted in summer and winter. Two experiments were carried out in soilless cultivation, one with transplantation in summer and the other with transplantation in winter, in a completely randomized design, with five harvest intervals (30, 45, 60, 72, and 90 days) and four replicates. Fresh and dry matter weights of leaves, branches and shoots were determined. The fresh matter weight of peppermint leaves and the daily growth rate of this trait were similar between the harvest intervals for the transplantation performed in the summer. The dry matter weight of leaves was higher for the intervals of 72 days (90.80 g plant^-1) and 90 days (90.24 g plant^-1). For the transplantation performed in winter, the fresh matter and dry matter weights of leaves were higher for the intervals of 60 days (660.54 g plant^-1, 107.14 g plant^-1) and 90 days (630.40 g plant-1, 105.95 g plant^-1). The same was observed for the daily growth rates of these traits. Peppermint harvests at 60-day intervals in winter transplantation are more appropriate for phytomass production. In summer transplantation, one can opt for the 45-day interval.

Characterization of organic composts produced by family farming for lettuce cultivation

2022-02-23T17:46:51-03:00

The use of organic compost in the cultivation of lettuce by family farming can be carried out in a sustainable way with the use of residues from the property, through composting. For efficient and safe use of these residues, it is necessary to monitor the composting process and adopt good agricultural practices for the production of safe food. Therefore, the objective was to identify and quantify contaminating microorganisms and to evaluate the chemical characteristics of organic compounds and their effects on the cultivation of lettuce produced in an organic system. Six periods of lettuce cultivation were studied using the organic compost produced in the planting fertilizer and cover. The results obtained for the fresh mass and the chemical analyzes of the compost, the soil and the plant were compared in a qualitative way. The results obtained from microbiological analyzes were compared to current legislation. The composition of the material used and the handling of the composting process influenced the chemical characteristics of the organic compounds applied to the soil. Organic compounds were efficient for plant nutrition, except for boron. The presence of thermotolerant coliforms was above the maximum acceptable limit, indicating contamination of the compound. The organic compost was not properly composted in most cycles. The use of organic compounds proved to be a sustainable alternative in the production of organic lettuce on family farms, but the study indicated the need for technical training.

Growth and production of lettuce on substrates based on detritivorous earthworms drilocomposts

2022-02-23T17:46:36-03:00

Alternative plant growing inputs have been increasingly sought out to reduce the economic-environmental impacts of intensive use of synthetic fertilizers in conventional agriculture. This study aimed to evaluate the production components of lettuce in response to the use of earthworm compost in substrate compositions. The experiment was carried out in a greenhouse using a completely randomized design in a 3 x 5 factorial scheme, with six replications, testing three earthworm species (Eisenia andrei, Eudrilus eugeniae, and Perionyx excavatus) and five drilocompost ratios (0%, 25%, 50%, 75%, and 100%), produced by these species and added to the composition of substrates by mixing them with soil. Production components evaluated comprised total and commercial numbers of leaves, commercial fresh weight, as well as shoot and total fresh and dry weights. Lettuce production components increased as the drilocompost ratio in substrates was raised, regardless of the earthworm species. Moreover, the addition of 25% this drilocomposted material in the dystrophic soil was enough to improve its fertility condition. In general, substrates prepared with worm castings from Perionyx excavatus and Eudrilus eugeniae were more efficient in increasing lettuce production components than that from Eisenia andrei.

General aspects of tomato culture and phosphate fertilization: a systematic review

2022-02-28T19:16:58-03:00

O tomate ( Solanum lycopersicum L.) is at the top of the ranking among the most consumed vegetables in the world and can be grown in open fields and, mainly, in agricultural greenhouses. Therefore, the adjustment of phosphate fertilizer in its cultivation can influence higher yields, fruit quality and nutritional status. In view of the socioeconomic importance of tomatoes due to their antioxidant properties, bioactive compounds, carbohydrates, proteins, minerals and the guarantee of jobs for farmers, this literature review seeks to present a study that provides technical and scientific data on general and the important role of phosphate fertilization in tomato cultivation. The main focus of this study is justified by the absence of studies that analyze the general aspects and the responses of the tomato in function of the water deficit and doses and sources of phosphorus. Through the analysis of secondary data available in the literature related to the theme, there is a difficulty in adjusting the phosphate fertilizer according to the appropriate choice of doses and sources to be applied. Furthermore, as it is a vegetable sensitive to water deficit, fruit yield and quality can be influenced by the amount of water that is applied and the management of irrigation in combination with the correct amount of fertilizer.