Comunicata Scientiae

Ecophysiology of the Southern Highbush blueberry cv. Biloxi in response to nitrogen fertigation

2020-05-26T18:10:36-03:00

In Brazil, the nutritional requirements of the blueberry are not sufficiently known, thus requiring further research on the management of mineral fertilization. In this perspective, this work aimed to evaluate physiological attributes of Southern Highbush blueberry plants cv. Biloxi as a function of nitrogen fertigation in Brasília-DF. The experiment was conducted from August 2018 to July 2019, in the Fruit Sector of the Experimental Biology Station of the University of Brasilia (UnB), Federal District. This experiment adopted a randomized block design, with four treatments: 10; 20; 30, and 40 g of N plant-1, 8 replications, and 5 plants per experimental plot. The following variables were measured: net photosynthesis rate (A), transpiration (E), stomatal conductance (gs), internal CO2 concentration (Ci), instantaneous water-use efficiency (WUE), carboxylation efficiency (CE), SPAD index (SPAD) and leaf nitrogen (N). There was an effect of the different nitrogen doses applied on the physiological attributes. The plants of the blueberry cultivar Biloxi increased their photosynthetic rates at doses up to 30 g of N plant-1. Nitrogen rates did not influence stomatal conductance nor did they provide improvements in the carboxylation efficiency of the blueberry plants. Under the conditions of the present work, the highest N leaf contents were obtained with the application of 30 g N plant-1, and values above this concentration did not correspond to higher net photosynthesis rates, transpiration, and CO2 concentration in the leaf mesophyll.

Physiological indices and phytomass partition in precocious dwarf cashew clones irrigated with saline waters

2020-05-26T18:14:56-03:00

This research aimed to evaluate the physiological indices and the accumulation of phytomass in clones of precocious dwarf cashew under salt stress during rootstock formation. The experiment was conducted in greenhouse in the municipality of Pombal-PB. The experimental design was in randomized blocks, and the treatments were organized in a 5 x 3 factorial arrangement, constituting the levels of electrical conductivity of the irrigation water - ECw (0.4 -Control; 1.2; 2.0; 2.8, and 3.6 dS m-1) and the clones of precocious dwarf cashew (Faga 11, Embrapa 51, CCP 76), with three replications and two plants per plot. Water salinity higher than 0.4 dS m-1 resulted in a decrease of the relative growth in plant height, leaf area, and phytomass accumulation in the cashew plant. The cashew clones are sensitive to water salinity from 0.4 dS m-1. Among the physiological indicators, the leaf area ratio, the sclerophylly index, and the root/shoot ratio of the precocious dwarf cashew are highlighted as salt stress indicators. The use of water with 0.4 dS m-1 of electrical conductivity is recommended for the formation of cashew rootstocks.

Management of soil cover and its influence on phytosociology, physiology and fig production

2020-05-26T18:29:41-03:00

The fig stands out as an important source of food for the human diet, especially minerals and fibers. Weeds are a major concern in the conduct of fig orchards. Therefore, the objective of this study was to evaluate the effect of management of vegetable cover of soil (CVS) on weed phytosociology, physiological characteristics and fig production. The experimental design was a randomized complete block design with four replications. The treatments consisted of six CVS managements: cover maintenance, weeding, lodging, mowing, application of herbicides diquat and glyphosate. For the constitution of the vegetal cover a consortium of three winter forage species, vetch and black oats sowed and the ryegrass remaining in the area of previous years were used. Thus, we evaluated the phytosociology of weeds present in the area, at two different times, assigning parameters related to frequency, density and abundance, which establish the species importance value index (IVI), besides the dry mass of the aerial part of the weeds. Physiological parameters and total fruit yield were evaluated at the end of the crop cycle. The different CVS management methods influenced the weed community, mainly in the diversity, density and dry mass of the aerial part. There is no interference in the physiological variables of the fig plants and in the total production of fig fruits. We highlight the maintenance of coverage and lodging as the most promising for the management of weeds found fig orchards.

Physiological responses of beet plants irrigated with saline water and silicon application

2020-05-26T18:32:39-03:00

Although not considered an essential element, silicon can be used to increase crop productivity, especially under stress conditions. In this sense, the objective was to evaluate the gas exchange of beet plants irrigated with saline water depending on the application of silicon. The experiment was conducted in a randomized block design, in a 5 x 5 factorial, referring to five levels of electrical conductivity of irrigation water (ECw): (0.5; 1.3; 3.25; 5.2 and 6.0 dS m-1) and five doses of silicon (0.00; 2.64; 9.08; 15.52 and 18.16 mL L-1), with six beet plants as an experimental unit. The effect of treatments on beet culture was evaluated at 30 and 60 days after irrigation with saline water from measurements of internal carbon concentration, stomatal conductance, net photosynthesis rate, instantaneous water use efficiency and instantaneous carboxylation efficiency using the LCpro+Sistem infrared gas analyzer (IRGA). Irrigation with saline water reduced the gas exchange of beet plants at 60 days after irrigation, but at 30 days after irrigation, the use of saline water increased stomatal conductance, transpiration rate and internal carbon concentration. The application of silicon decreased stomatal conductance, internal carbon concentration and efficiency in the use of water, but increased the rate of net photosynthesis, the rate of transpiration and instantaneous efficiency of carboxylation at 30 and 60 days after irrigation.

Production of Formosa papaya seedlings irrigated with wastewater and application of biostimulant

2020-05-26T18:35:53-03:00

Papaya (Carica papaya L.) is one of the leading fruit trees in Brazil, mainly in the Northeast region. However, some regions suffer from water scarcity, making wastewater reuse a viable alternative for crop production. Also, biostimulants may be used to maximize papaya growth and development. Thus, this work aimed to evaluate the use of Acadian® biostimulant in the growth of Formosa papaya seedlings irrigated with different concentrations of fish-farming wastewater. The experiment was block randomized in a 2 x 5 factorial scheme, use and non-use of biostimulant and five concentrations of wastewater (0, 10, 20, 30, and 40%) diluted in potable water, with four replicates. Qualitative data were compared by t-test at 5% probability, and quantitative data were submitted to regression analysis. Results showed that high concentrations of wastewater negatively affect the production of Formosa papaya seedlings. Acadian® negatively influences plant height, number of leaves, and the ratio between shoot and root. However, the seaweed biostimulant positively influenced the chlorophyll content index.

Cymbopogon citratus essential oil has hepato/renal protection and anti-genotoxicity against carbon tetrachloride

2020-05-26T18:43:03-03:00

Nowadays, there is an increasing trend to use aromatherapy for treatment of various diseases. Cymbopogon citratus (Lemongrass) is one of many plants which have been reported to employ successfully in aromatherapy. Herein we decided to explore the protective role of Cymbopogon citratus essential oil (CCEO) against hepato/renal damage and genotoxicity induced by carbon tetrachloride (CCl₄) and the relation of this bioactivity with its chemical constituents. Six main groups of mice (five/each) were examined: I- represents negative control group, II and III- mice received oral treatment with CCl₄(1mL/kg, positive control) and CCEO (0.3 mL/kg, control plant) respectively for five consecutive days and IV-VI- represent groups of mice treated with CCEO at the three concentrations 0.1, 0.2, 0.3 mL/kg plus CCl₄
(five consecutive days treatment). Remarkable adverse effects of CCl₄in all the tested parameters were recorded. These effects were distinguished as an increment in the level of all liver marker enzymes (ALT, AST, ALP, γ-GT), blood urea, and creatinine. Also the oxidative stress biomarkers: malondialdehyde (MDA) and glutathione-transferase GST were affected after CCl₄treatment. Regarding to the genotoxic effect of CCl₄, the percentage of chromosomal aberrations in bone marrow and spermatocyte cells was elevated (p< 0.05) compared with the negative control. Notable antioxidant, hepato/renal protection and anti-mutagenic potency of CCEO against CCl₄were demonstrated with a dose-related relationship. GC/MS analysis demonstrated the presence of 12 phytochemical constituents which in combination play a critical role in its antioxidant/antigenotoxic efficacy. The major components exist were E. Citral (35.13%) and Geraniol (32.83%).

Increase of nutrients export and production of pitaya whit potassium fertilization

2020-07-13T17:51:47-03:00

Characterization works of pitayas show that the potassium (K) is the nutrient most exported, thus, influences in the productivity and quality of this fruit. However, these researches do not report the nutrients export by pitaya's associating the fertilization carried out in the orchard, information that is relevant to make the nutrients reposition adequate at the time of fertilization. The research was carried out to evaluate the supply of K2O in the export of nutrients and productivity of the Hylocereus undatus and Hylocereus polyrhizus pitaya species. The analysis was carried out in the mature fruits harvested in two harvests. Potassium fertilization was performed at doses of 0; 50; 100 and 200 g of K2O per plant. Nutrient export per ton of fruit was calculated from the determination of the nutrient levels and the dry matter of the pitaya pulp. The export of nutrients by the pitaya of the species H. undatus and H. polyrhizus occurs in the following order: K>N>P>Ca>Mg> and Mn>Fe>Cu>Zn>B. These species of pitaya have similar nutritional requirements, enabling them to be receive same fertilization management. The amount of nutrients exported was higher in plants fertilized with potassium due to the higher productivity achieved. Orchards of pitaya that reach high productivity require a greater quantity of nutrients, due to the increase export by the fruits.

Yield of new hemp varieties for medical purposes under semi-arid Mediterranean environment conditions

2020-07-13T17:51:45-03:00

Under the effects of climate change new drought tolerant crops are imperative to introduce in irrigated agricultural areas of Mediterranean countries. In this sense, hemp (Cannabis sativa L.) represents an alternative in many semi-arid agricultural areas of Mediterranean basin because of its low water requirements and cost effectiveness when it is developed under non controlled conditions. The aim of this work was to evaluate the potential yield of five new hemp varieties (Sara, Pilar, Aida, Theresa, and Juani) cultivated under high tunnel conditions in a semi-arid Mediterranean area, and also to study the effect of plant density on active biomass production and cannabinoids biosynthesis (cannabidiol, CBD and cannabigerol, CBG) at different plant positions. The trial was conducted under plastic macro-tunnels during two seasons (2014 and 2015), from May to October. The agronomic response and the chemical profiles of the studied varieties were evaluated at the end of each season. Moreover, it was monitored the differentiation in terms of active biomass production and cannabinoids biosynthesis in different plant organ positions (at upper, medium, and lower). Additionally, during the second season, three different plant densities (PD1, 9,777; PD2, 7,333; and PD3, 5,866 plants· ha-1) were tested in order to define the the best of them for maximizing CBD and CBG productions. The findings highlighted significant differences in yield between cultivars within the CBD and CBG. Moreover, plant density was a determinant factor related to active biomass production and cannabinoids contents, PD3 representing a suitable strategy to maximize the cannabinoids production minimizing the requirements of rooted apical cuttings. These results allowed concluding that these new hemp cultivars together with the adopted agronomic practices in this experience would be very appropriate for CBD and CBG productions, being determinant to consider the plant density and the cultivar for both studied chemotypes.

Morphophysiological characteristics of okra plants submitted to saline stress in soil with organic fertilizer

2020-07-13T17:51:41-03:00

The excess of salts may compromise the growth and physiological functions of plants, but the use of bovine organic fertilizer can mitigate these effects. It was intended was to evaluate the saline stress in soil with and without bovine organic fertilizer on the initial growth, the accumulation of biomass and the gas exchanges of the okra culture. The test was conducted at the UNILAB’s experimental farm, in Piroás, in Redenção – CE city. The treatments were distributed in a completely randomized design with five replications, in a 5 x 2 factorial concerning five irrigation water salinity levels (1.0; 2.0; 3.0; 4.0 and 5.0 dS m-1), in the presence and absence of bovine organic fertilizer. Plant height, stem diameter, root length, a dry mass of shoot, photosynthesis, transpiration and stomatal conductance were evaluated. The bovine organic fertilizer promoted better means in initial growth and biomass in okra plants compared to the control treatment, thus showing efficiency in the attenuation of the salts present in irrigation water. The increase in the saline concentration of the irrigation water reduced the gas exchange (photosynthesis, stomatal conductance and transpiration) in okra plants. Nonetheless, in smaller proportions in the soil with the bovine organic fertilizer.

Physico-chemical properties of different formulations of pequi pulp with milk

2020-07-13T17:51:43-03:00

The objective of this work was to perform the physical-chemical characterization of different formulations of the pequi pulp with the addition of different concentrations of whole milk, in order to identify promising products for commercial use. Three formulations of pequi pulp with whole milk were prepared: PL1- 90% pequi pulp and 10% milk, PL2 - 70% pequi pulp and 30% milk, PL3 - 50% pequi pulp and 50% milk. The formulations were evaluated for physical and physical-chemical parameters of color, water activity, water content, ash, total soluble solids (SST), pH, total titratable acidity (ATT), SST/ATT ratio, ascorbic acid, proteins, lipids, total, reducing and non-reducing sugars. The data obtained were subjected to analysis of variance (ANOVA) and comparison between means by the Tukey test at 5% probability. Among the three tested formulations, the best results were obtained for PL3, where it presented lower total titratable acidity, water activity, red intensity, yellow intensity and chromaticity, however, higher content of total soluble solids, ratio SST/ATT, ash, lipids, sugars (total, dimmer and non-dimmer), luminosity and tint angle. The inclusion of milk in the pequi pulp changed the physical and physical-chemical characteristics of the pulp, and it can be an alternative to add nutritional value to the fruit and consequently a promising product for the market.

Agronomic performance of blackberry cultivars in environmental protection area

2020-07-13T17:51:38-03:00

The demand for blackberry has been increasing due to the results of studies on its nutraceutical properties. Moreover, the rusticity of its plants allows its cultivation with reduced use of pesticides, becoming feasible to grow it in areas of environmental protection (APA). As a non-traditional crop in the country and its requirement in specific climatic conditions, there is a lack of studies about management techniques and the adaptability of cultivars in different regions. Thus, it is necessary to study phenological behavior and fruit quality in potential regions. Therefore, this work aimed to verify the adaptability of blackberry cultivars in environmental protection area in Pinhais – PR (Brazil), with no use of pesticides, as well as to evaluate the quality of the fruits produced under this condition, focusing on the recommendation of the cultivars more adapted and the best destination of fruits produced. For this, the phenological and productive performance of seven blackberry cultivars: Tupy, Guarani, Cherokee, Xavante, Brazos, Choctaw, and Arapaho were observed during the cycles of 2017/2018 and 2018/2019. Brazos cultivar had the earliest harvest period, Guarani and Xavante cultivars were intermediate and Tupy and Cherokee cultivars were later in the region. The highest yields were obtained with the cultivars Tupy, Guarani, Xavante, Cherokee, and Brazos. The harvest period extended from November to January. Tupy cultivar produces larger fruits and is the most recommended for marketing as fresh fruit. Other cultivars are recommended for industrialization.

Phytotechnical parameters and yield of watermelon plants under different irrigation and nitrogen levels

2020-07-13T17:51:40-03:00

Water and nitrogen availability are fundamental for obtaining a high yield of the watermelon plant. However, the appropriate levels of irrigation and nitrogen to be applied according to specific cultivation conditions should be previously determined. The objective of the present study was to evaluate the effects of irrigation and nitrogen levels in fertigation on the phytotechnical parameters and yield of the Top Gun hybrid watermelon plant. The experiment was conducted at São Luiz Ranch, in Bom Jesus (PI), from August 4 to October 15, 2015. The blocks in strips experimental design was used with four repetitions, and the treatments consisted of five irrigation depths (114.17, 156.86, 221.16, 268.87, and 317.09 mm) and five doses of nitrogen in fertigation (0, 50, 100, 150, and 200 kg ha-1). The growth rate of the main and primary branches, leaf area, specific leaf area, stem diameter, dry mass of the aerial part, number of fruits, and commercial production per plant were evaluated. Both hydric and nutritional stress caused decreased growth rates, leaf areas, and specific leaf areas, and the highest growth expressions were found with the combination of a 317.09 mm irrigation depth and 200 kg ha-1 nitrogen. The irrigation depths did not influence the diameter of the stem nor the accumulation of dry mass. Nitrogen doses did not influence the number of fruits and production. The 247.95 mm irrigation depth promoted the highest commercial fruit production of the watermelon plant.

Foliar application of biofertilizer in semi-hydroponic lettuce fertigated with saline nutrient solution

2020-07-13T17:51:34-03:00

Water scarcity in the world is a problem diagnosed especially in countries with large semi-arid regions such as Brazil. Research has been conducted with a view to making use of saline waters as an input for cultivation, particularly in hydroponics, with especial focus on lettuce, the most prominent leafy vegetable in Brazil. The objective of this study was to evaluate the development of lettuce in a semi-hydroponic system fertigated with saline water and under foliar fertilization with biofertilizer. The present study was carried out in a greenhouse located in the experimental area of the Department of Environmental and Technological Sciences (DCAT) of the Federal Rural University of the Semi-Arid Region, in the municipality of Mossoró, RN, Brazil. The experimental design was a randomized complete block design, with treatments arranged in a 2 x 4 factorial scheme, with 4 replicates, two salinity levels of the water used to prepare the nutrient solution (0.5 and 3.5 dS m-1) and four biofertilizer concentrations (0, 20, 40 and 60%) applied by foliar spraying. The evaluated characteristics were: shoot diameter, stem diameter, number of leaves, fresh mass, dry mass, leaf succulence, leaf area and specific leaf area. The use of saline water to prepare the nutrient solution reduces fresh mass and dry mass production in the lettuce crop. The biofertilizer can be applied through the leaves at concentration of up to 20%, promoting greater plant growth.

Macronutrient fertilizers on basil growth and yield

2020-07-13T17:51:33-03:00

The objective of this work was to determine the macronutrient doses that allow the highest phytomass yield and growth of basil plants. The experiment was carried out in the experimental area of the Federal University of Recôncavo da Bahia, in Cruz das Almas, BA, in a greenhouse. The treatments were obtained according to the Baconian matrix statistical arrangement, in which one of the nutrients is supplied in variable amounts, while the others are kept at a referential level. Six nutrients (nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and sulfur (S)) were evaluated in three different doses, and two additional treatments, one with reference doses and another without nutrient addition, totaling 20 treatments that were arranged in a completely randomized design with five replications, totaling 100 experimental units. At 50 days after treatment distribution, the growth parameters were evaluated: Plant height, number of leaves, leaf dry mass, stem, root and leaf area. It was observed that the highest leaf dry mass accumulation was estimated with the dose of 250 mg dm³ of N giving an average of 8.01g per plant, being significantly higher when compared to all other tested elements, this parameter is extremely relevant because the leaves are characterized as the main product of this species. Phosphorus doses allowed significant results in height and leaf area, whereas K favored higher leaf emission. Positive responses were verified for nutrients Ca, Mg and S in all parameters tested at levels above those tested as reference.

Saline water and nitrogen doses in the cultivation of West Indian cherry in the post-grafting phase

2020-07-13T17:51:31-03:00

This study aimed to evaluate the photosynthetic pigments and growth of the West Indian cherry cv. BRS 366 Jaburu in the post-grafting phase as a function of the salinity levels of the irrigation water and nitrogen fertilization under greenhouse conditions, in the municipality of Campina Grande-PB. The study was performed in randomized blocks, consisting of two levels of electrical conductivity of irrigation water - ECw (0.8 and 4.5 dS m-1) and four nitrogen doses (70, 85, 100, and 115% of the recommended dose for the crop), with three replications. The synthesis of chlorophyll a and carotenoids in the West Indian cherry plants was inhibited with ECw of 4.5 dS m-1. Nitrogen fertilization in the estimated doses of 92 and 80% of N reduced the effects of salt stress on the contents of chlorophyll a and b in West Indian cherry plants, at 630 days after transplanting. The increment in nitrogen fertilization increases quadratically the absolute and relative growth rate of the diameter in the rootstock of the West Indian cherry plants under irrigation with saline waters.

Post-harvest storage of ‘Paluma’ guavas produced by plants fertirrigated with nitrogen and biofertilizer

2020-07-13T17:51:30-03:00

The association between mineral fertilizer and biofertilizers can contribute to guavas quality. An experiment was carried out in order to assess, over the days, 'Paluma' guavas physical-chemical quality in function of nitrogen fertilizer and biofertilizer doses. It was adopted a randomized blocks with treatments distributed in a factorial 5 x 2 x 5 referring to evaluation days post-harvest (0, 3, 6, 9 and 12), nitrogen fertilization (50 and 100% culture recommendation) and application of bovine biofertilizer doses by fertigation (0.0, 2.5, 5.0, 7.5 and 10.0%). The physical-chemical quality of 'Paluma' guava fruit was influenced by the association between liquid bovine biofertilizer and nitrogen fertilization. This combination increased soluble solids, titratable acidity, ratio, vitamin C, pH, firmness and loss of fresh mass, but did not affect the pulp percentage. The bovine biofertilizer, together with mineral fertilization, is important to increase the post-harvest quality of 'Paluma' guava.

Chickpea production in response to fertilization with zinc and doses of phosphorus

2020-07-13T17:51:28-03:00

Chickpea cultivation in Brazil has not yet been consolidated, and studies aiming at the adequate nutritional management for this crop are necessary. This work aimed to evaluate the production of chickpea plants (cultivar BRS Aleppo) subjected to fertilization with zinc and P doses. The experimental was completely randomized, with four replications, in a 3 x 5 factorial scheme, corresponding to three fertilization treatments with Zn (without Zn addition; 50% of Zn applied at sowing, via soil + 50% applied at flowering, via leaves; and 100% applied at sowing, via soil) and five doses of phosphorus (0, 60, 120, 180, and 240 kg ha-1 of P2O5). The 100-grain mass (M100), pod mass (MV), number of pods (NV), number of grains (NG), total grain mass (MGT), yield (PROD), dry matter of the shoot part (MSPA) and plant residues (MSRV), and agronomic efficiency (EA) were characterized. There was an isolated effect of the P doses on the M100, MGT, PROD, MSPA, and MSRV characteristics. The application of 240 kg ha-1 resulted in an increase in the production components and a maximum yield of 3,018 kg ha-1, indicating the need to adopt higher doses of P2O5 to increase chickpea production in tropical soils. However, the highest agronomic efficiency was obtained after the application of 60 kg ha-1 of P2O5, along with Zn at sowing.

Water-retaining polymers on the early growth and quality of bushy cashew (Anacardium humile A. St. Hill) seedlings

2020-07-13T17:51:27-03:00

Bushy cashew (Anacardium humile A. St. Hill) is an endemic plant species to the Brazilian Cerrado, a region characterized by scarce and poorly distributed rainfall. The use of hydrogel, a water-retaining polymer that features massive water storage and promotes its release into the environment throughout time may be an alternative to reduce the frequency irrigation in the production of bushy cashew seedlings. This study aimed to evaluate the quality and early growth of bushy cashew seedlings as a function of hydrogel doses. The experimental design adopted was in five randomized blocks, with five hydrogel doses (0; 1,0; 2,0; 3,0; and 4,0 g L-1 of soil), and each plot consisting of 10 seedlings, totaling 250 plants. A Yellow Latosol with sandy-loam texture was used for seedling production. The growth evaluation was performed through the variables of emergence speed index, germination percentage, height, diameter, root volume, number of leaves, shoot dry mass, root dry mass, and the Dickson quality index. The results revealed a positive influence of the hydrogel on the growth and quality of bushy cashew seedlings, notably at the dose of 4 g L-1 of soil.

Pollination techniques in zucchini production in the presence of boron fertilization

2020-07-13T17:51:24-03:00

Zucchini (Curcubita pepo L.), known in Brazil as “abóbora de moita”, belongs to the Cucurbitaceae family and is among the top ten vegetables produced and of highest economic value in Brazil. The present study aims to evaluate the efficiency of different forms of pollination in zucchini plantations subject to boron fertilization. The experimental design used was randomized blocks in a 4 x 2 factorial arrangement, with four replications. The treatments consisted of a combination of four pollination methods (fruiting induced with 2,4-dichlorophenoxyacetic acid (2,4-D); manual pollination; natural pollination by bees and control) and boron fertilization (absent and in the soil at a dose of 2 kg ha-1). The percentage of flowering was evaluated and, of the harvested squashes, the diameter, length and average weight of the commercial fruits (those uniform in terms of shape, size, and color) were recorded. The application of 2,4-D promoted the greatest fruit setting rate, diameter, length and mass in the squash. 2,4-D promoted the development of parthenocarpic fruits and can be used to promote yield gains in zucchini production.

Pruning management of ‘Marselan’ grapevines in the Serra do Sudeste region, in Southern Brazil

2020-07-13T17:51:25-03:00

The agronomical behavior of the ‘Marselan’ grapevine, indicated for the production of high-quality fine wines, is related to the management of the vineyard and the edaphoclimatic conditions of the cultivation region. This work aimed to evaluate the vegetative, productive, and qualitative behavior of ‘Marselan’ grapevines subjected to the Spur Pruning and Double Guyot pruning systems, cultivated in a municipality belonging to the Serra do Sudeste region, RS state, Brazil. The ‘Marselan’ grapevines were conducted in a vertical shoot positioning training system over a ‘Paulsen 1103’ rootstock, in a commercial vineyard located in Encruzilhada do Sul, RS, Brazil. During the 2016/2017 and 2017/2018 cropping seasons the vegetative vigor, the mass of pruned shoots, Ravaz Index, production, and chemical-physical composition of the must were evaluated. The double Guyot pruning system in the ‘Marselan’ grapevines induced a lower plant vigor, promoted an increase in the number of bunches per plant, bunch mass, production, and yield. The pruning type interferes with the vigor and yield of the ‘Marselan’ grapes without altering must quality. In the management of the cv. ‘Marselan’ in the Serra do Sudeste region, Brazil, the double Guyot pruning system is the most indicated.

Dormancy overcoming in seeds of cajá-manga (Spondias dulcis)

2020-07-13T17:51:22-03:00

The propagation of ‘cajá-manga’ (Spondias dulcis) is usually performed by seeds. The presence of dormancy is an obstacle for seedling production and the commercial use of its main product, the fruit. This research aimed to evaluate the use of phytoregulators associated with the scarification of the distal region of the embryo in dormancy overcoming and in the standardization of germination of ‘cajá-manga’ seedlings. Endocarps extracted from fruits of six matrices were subjected to the following treatments: control (T1), mechanic scarification in the distal region of the embryonic axis (T2); all following treatments involved scarification and imbibition in a solution of: water for 6h (T3); GA3 (750 mgL-1) for 6h (T4); GA3 (350 mg L-1) for 12h (T5); Cytokinin (750 mg L-1) for 6h (T6); Cytokinin (350 mg L-1) for 12h (T7); GA3 and Cytokinin (750 mg L-1) for 6h (T8); and GA3 and Cytokinin sowing 25 endocarps in expanded polystyrene trays using a washed sand substrate. The following variables were evaluated: emergence, first emergence count, emergence speed index, mean emergence time, shoot and root length of seedlings, and relative emergence frequency. The experimental design was in randomized blocks, with 9 treatments and four replications consisting of 25 endocarps each. The data obtained were subjected to the F Test at a 1% level of probability, as well as to the Scott-Knott method. The use of mechanic scarification in the opposite region of the embryonic axis, followed by the imbibition in a solution of gibberellin + cytokinin at the concentration of 350 mgL-1 for 12 hours is promising for dormancy overcoming in seeds of Spondias dulcis.

Bell pepper yield as a function of an alternative source of organic matter

2020-07-13T17:51:20-03:00

For a good development and a consequently high production, the bell pepper requires, among other conditions, satisfactory levels of soil fertility. In this perspective, this work aimed to evaluate the parameters of production and productivity of the bell pepper cultivar ‘Casca Dura Ikeda’ cultivated in field conditions, with different doses of buriti stem, in Bom Jesus, Piauí. The experiment was conducted at the Horticulture Department of the Campus Professora Cinobelina Elvas of the Federal University of Piauí (CPCE/UFPI). The experimental design was in randomized blocks with treatments distributed in plots referring to organic fertilization. There were five (5) doses of buriti stem (0, 10, 20, 30, and 40 t ha-1) plus an additional treatment (bovine manure and NPK mineral fertilizer), with four replications and an experimental unit consisting of twenty plants. The following variables were analyzed: number of fruits per plant, mean fruit length, basal diameter, mean thickness of the fruit pulp, mean fruit weight, production, and yield. We concluded that the yield attributes of the bell pepper cv. ‘Casca Dura Ikeda’ are influenced by organic fertilization, and production is increased by the buriti stem doses of 20 t ha-1 and 30 t ha-1 and by the use of the combination of manure and mineral fertilizer.

Chemical soil and leaf properties in yellow passion fruit cultivation with organic fertilization

2020-07-13T17:51:17-03:00

The yellow passion fruit presents a high nutritional demand, and successive cultivations in the same area lead the soil to nutritional exhaustion, creating the need for restitution through fertilizers. In the context of organic managements, alternatives must be sought, which, besides improving soil fertility, can increase the contents of soil organic matter. Therefore, this work aimed to evaluate the effect of organic basal fertilization in passion fruit cultivation on the chemical properties of the soil and nutrient contents of the plant. Two experiments were performed in two rural properties, with soils presenting sandy-loam and clay-loam texture. The experimental design was in randomized blocks (RBD), with 5 treatments and 4 blocks. The treatments consisted of the application of organic compost in different planting hole diameters: 0.4 m; 0.8 m; 1.2 m; 1.6 m, and 2.0 m, and their respective volumes of organic compost: 0.0007 m³; 0.03 m³; 0.06 m³, 0.10 m³; 0.16 m³. The chemical characteristics of the soil and the foliar content of nutrients were evaluated. Soil texture interferes with the effects of organic fertilization. Regardless of the texture, fertilization increases the contents of organic matter and P in the soil. The successive organic cultivation in a sandy-loam soil increases the content of P and provides higher foliar contents of N, P, Ca, Mg, S, B, Cu, Fe, Zn, and Na.

Cutting propagation of ‘Cambona 4’ yerba mate clones

2020-07-13T17:51:15-03:00

The ‘Cambona 4’ yerba mate (Ilex paraguariensis A. St. Hil. - Aquifoliaceae) stands out for the high productivity and soft taste of the raw material obtained. The seedlings come from the controlled crosses of a female and a male plant. In order to guarantee the planting of even more uniform and productive herbs, the cutting is an alternative of propagation. The objective of this research was to evaluate the rooting capacity of apical and subapical cuttings of six ‘Cambona 4’ clones (C7, C8, C9, C10, C11 and C13) in two seasons, in january (summer/autumn) and april (autumn/winter) treated with 2.000 mg/kg of IBA in the form of talc. The cuttings were standardized with 10 cm, keeping a pair of leaves cut in half. The cutting was done in an agricultural greenhouse, with irrigation by intermittent nebulization, the cuttings were placed to rooting in plastic tubes containing carbonized rice husk. After 120 days, it was verified that the cutting season influenced the response of each clone, but for most clones rooting was higher when performed in summer/autumn, with better rates varying between 78.2% to 90.6% (C8, C9, C11 and C13), while in autumn/winter it was from 59.4% to 75.0% (C7, C10, C11 and C13). In the summer/autumn cutting period, subapical cuttings showed greater survival and rooting than the apical ones, but they didn’t differ when performed in autumn/winter. Leaf retention positively influenced the survival.

Phenolic compounds and fatty acids content of some West Algerian olive oils

2020-07-13T17:51:14-03:00

Olive represents the most widespread fruit cultivated in Algeria. Olive oil is the primary source of added fat in the Mediterranean diet with health benefits of which have been verified for millennia. Interest in phenolic compounds in olive oil has increased due to its antioxidant activity, which plays a very important role in human health. The present study is carried out to study the phenolic compounds and fatty acids profile of some olive oils from western Algeria. The quality parameters (acidity, peroxide value, K232, K270), tocopherol analysis, fatty acid composition and phenolic profile were determined by High performance chromatography (HPLC). The results showed that chemlal oil (SBA) recorded the highest level of tocopherol-α with 228.12 mg/Kg. Regarding the fatty acid composition, oleic acid was the most dominant, oil Oleaster (Bensekrane) records the highest percentage (72.80%) of oleic acid. The quantitative data on the phenolic content of the seven samples revealed that chemlal oil (SBA) had the highest level of polyphenols (328.99 mg/Kg). However, Sigoise oil (Sebra1) was characterized by the highest levels of tyrosol and hydroxytyrosol (15.89 mg/kg and 22.42 mg/kg, respectively). The highest concentrations of oleuropein derivatives and ligstroside derivatives were observed in chemlal oil (SBA) and the recoreded values were 105.97 mg/Kg and 83.49 mg/Kg, respectively. Chemlal oil (SBA) was characterized by the highest amount of lignans (35.93 mg/Kg), luteolin (10.16 mg/Kg) and apigenin (5.44 mg/Kg). Oleocanthal was found in all the tested samples and it was higher in Chemlal oil (102.43 mg/kg).

Population structure of Annona coriacea Mart. (Annonaceae) in different Cerrado phytophysiognomies

2020-07-13T17:51:13-03:00

Knowing the regeneration and structure of a species in different phytophysiognomies is extremely important to understand its pattern of occurrence. In spite of its importance, this type of study is still scarce in the Cerrado biome. In this perspective, this work aimed to compare the structure of the arboreal and regenerating strata of Annona coriacea in the cerrado sensu stricto and in the cerradão (savanna woodland). For that purpose, 13 plots of 400m² were installed in each physiognomy. All individuals of A. coriacea were sampled and had their diameter and height measured. The individuals were divided into regenerating and arboreal and were distributed in classes of height and diameter. Furthermore, the absolute density and the basal area of each extract were calculated in each physiognomy. The parameters were compared using the T-test. In total, 130 individuals of A. Coriacea were sampled, with 42 regenerating individuals in the cerrado sensu stricto and 49 in the cerradão. As for the arboreal individuals, 33 were sampled in the cerrado sensu stricto and 6 in the cerradão. All evaluated parameters revealed to be significantly different for the physiognomies. Based on these results, it is possible to affirm that A. coriacea did not present a distribution pattern in the two physiognomies, although it presents a better establishment success in the cerrado sensu stricto. In the cerradão, although the seeds can germinate, the seedlings fail to develop and reach the adult age.

Morphological and physiological changes in papaya seedlings irrigated with saline water and application of humic substances

2020-07-13T17:51:11-03:00

In the northeast semiarid region water with high salt content is very common, which may negatively affect crops growth and development. Thus using possible salt stress attenuators is extremely important because it allows the use of saline waters for agricultural purposes. Among the possible attenuators of salt stress, humic substances stand out. This work was driven in order to evaluate the effect of the application of humic substances as a possible attenuator of salt stress from papaya seedlings irrigation. The experiment was conducted under entirely randomized design with five replications in a 4 x 4 factorial, regarding the four doses of humic substances (5, 10, 15 and 20g), and the electrical conductivity of the irrigation water (ECw 1.5; 3.0; 4.5 and 6 dS m^-1). When it irrigates the papaya seedlings with water of 6.0 dS m^-1 is recommended dose of 20 g of humic substances, which provided growth. Irrigation of papaya seedlings with high salinity (3.0 and 4.5 dS m^-1) allied with application of 20 g of humic substances provide increased CO₂ concentration, transpiration rate, instantaneous water use efficiency, carboxylation efficiency and chlorophyll b content, however, stomatal conductance, net photosynthesis and chlorophyll a content are reduced with increase of the ECw.

Effect of isolates of entomopathogenic fungi in the coconut eye borer

2020-07-13T17:51:09-03:00

The objective of this study was to evaluate the effect of entomopathogenic fungi on adults of Rhynchophorus palmarum (Coleoptera: Curculionidae). The experimental design was completely randomized in a factorial design (5x3) + control, composed of five treatments (isolated IBCB 66, CPATC 032, CPATC 057 and T9, and the commercial product Boveril®) and three concentrations of each fungus (107, 108 and 109 conidia.mL-1). The data of confirmed mortality were submitted to analysis of variance (ANOVA) using the Proc ANOVA of SAS, and the means compared by Tukey test at 5% probability. To determine percentage survival, confirmed mortality data were subjected to Log-Rank test using the Kaplan-Meyer method. Subsequently the values of LC50 and LT50 were estimated submitting mortality confirmed the Probit analysis. For the concentration 108 conidia.mL-1, the isolates CPATC 032 and CPATC 057 caused confirmed mortality of 52 and 44% of the adults of R. palmarum, respectively. At the concentration 109 conidia.mL-1, the isolates CPATC 032 and CPATC 057 caused mortality of 64 and 52% of the insects, respectively. For the CPATC 032 isolate, in the three concentrations tested, the insects had an average survival of 11 to 12 days. The TL50 of isolate CPATC 032 at concentrations 108 and 109 conidia.mL-1 was approximately 17 days. All isolates tested and the Boveril® product are pathogenic to R. palmarum.

Fruit yield and quality of Palmer mango trees under different irrigation systems

2020-07-13T17:51:07-03:00

Mango production has been having a great economical expression in the Brazilian agriculture. However, the economic crisis and increased competitiveness of the international market required improvements in the crop efficiency for its sustainability. In this context, the objective of this work was to evaluate the effect of different irrigation system on the physiology and fruit yield and quality of Palmer mango trees in the semiarid conditions of the Lower Middle São Francisco Valley, Brazil. The experiment was carried out at the Agranvil Farm, in Petrolina, state of Pernambuco, Brazil, with harvests in July 2013 and October 2014. A randomized block statistical design was used, with four treatments replicated in 5 blocks, during two production cycles. The treatments consisted of four irrigation systems: one micro sprinkler under the plant canopy (MSPC); drip system with two lateral lines per plant row (DSLL); one micro sprinkler between plants (MSBP); and ring-shaped drip system around the plants (RSDS). All treatments provided a flow rate of 56 L h-1 plant-1. The physiological characteristics evaluated were: photosynthesis, stomatal conductance, leaf transpiration, and leaf temperature. Fruit yield, quantity, mean weight, volume, soluble solid content, titratable acidity (TA), density, and pulp firmness were evaluated after the harvest. The evaluated treatments presented significant differences for the physiological variables. The treatment DSLL provided higher number of fruits and fruit yield, and the treatment MSBP provided the lowest results for these variables.

Pineapple quality in a traditional cultivation system in different soil classes

2020-07-20T21:24:25-03:00

Pineapple (Ananas comosus (L.) Merril) is considered one of the most important fruits of the tropical and subtropical regions, and the third most-produced in the world due to its high commercial expansion in the world market, in recent years. Therefore, this work aimed to evaluate the influence of landscape position on pineapple quality. The work was developed at the Providência Farm, located in the municipality of Miracema do Tocantins. The following soil parameters were evaluated: hydraulic conductivity - KS, soil bulk density – DS, and total porosity – TP, as well as the following quality attributes: titratable acidity - TA, length and diameter of infructescences, total fresh mass - TM, fresh mass of infructescences – IM, and soluble solids – SS. The analyses were performed at the Agri-Environmental Laboratory of the Agricultural Sciences Complex of the Federal University of Tocantins. Less massive infructescences developed on more porous soils. The variation in the mass of infructescences is not associated with soil types, but rather with soil porosity. Soils with higher KS tend to increase the chances of producing infructescences with high acidity and high levels of soluble solids. The DS did not result in a significant association with the pineapple quality attributes. The infructescences were not affected by the landscape position. No position in the landscape influenced fruit quality. In general, the infructescences showed low acidity and low levels of soluble solids, with length and diameter of infructescences below the standard of the cultivar ‘Pérola’.

Radish production under different shading screens and mulching

2020-07-20T21:30:51-03:00

Shading Screens and mulching may provide a favorable environment for radish growing in regions of adverse climates. This work aimed to evaluate the radish productivity under the influence of different shading screens associated with the presence and absence of mulch in two different years. The experiment was carried out in two different seasons (2017 dry season and 2018 rainy season), in the vegetable garden of Liberdade campus, at the University of International Integration of Afro-Brazilian Lusophony (Unilab), municipality of Redenção-CE. The experimental design was in randomized blocks in a split-plot arrangement, with four repetitions, in which the plots consisted of growing with and without mulching and in the subplots, five shading screens: 50% Black Shading Screen (50% BSS), 50% Red Shading Screen (50% RSS), 30% White Shading Screen (30% WSS), 70% Black Shading Screen (70% BSS) ), and full sunlight (FS). The red shading screens 50% and white 30%, in addition to cultivation under full sunlight, provide higher performance in terms of the number of leaves, tuberous root diameter, tuberous root matter, and the radish crop productivity, regardless of the evaluated period. The applied mulch does not influence the productivity of the rabante, influencing only the gain of dry mass of the aerial part, soluble solids and length of the tuberous root.

Arbuscular mycorrhizal fungi as mitigating agents of salt stress in Formosa papaya seedlings

2020-07-13T17:59:12-03:00

The objective of the present study was to evaluate the effect of mycorrhization on the nutritional, hydric and biochemical components of papaya seedlings, Carica papaia L., from the Formosa Group, Hybrid Tainung Nº 1, submitted to irrigation with saline water. The research was conducted at the Federal Institute of Paraíba, Sousa Campus, from March to December 2018. The experimental design used completely randomized blocks, with treatments arranged in a 4 x 5 factorial scheme, referring to the fungi species: Gigaspora candida, Acaulospora scrobiculata, Dentiscutata heterogama and without mycorrhizae, and the five salt concentrations in irrigation water: 0.0; 10.0; 20.0; 30.0 and 40.0 mmolc L-1 in four repetitions. The characteristics evaluated were: relative water content, water saturation deficit, membrane damage, photosynthetic pigments, concentration and accumulation of nitrogen, phosphorus, potassium, sodium and the relationship between potassium and sodium concentrations in leaf tissue. The species D. heterogama and G. candida presented the highest rates of leaf hydration and the lowest damage to biomembranes at all saline levels. Mycorrhizae increased the absorption of N and P, especially from 30 mmolc L-1 of salt. A greater relationship between potassium and sodium concentrations was evidenced in seedlings mycorrhized with D. heterogama.

Biofertilizer in leaf and drip applications: an alternative to increase tomato productivity

2020-07-20T22:20:46-03:00

The tomato is a species of undetermined growth and extremely demanding in nutrients Therefore, the search of new ways to maximize the use and supply of fertilizers sources and their application mechanisms are important to improve the tomato culture management. The aim of this study was to evaluate the application methods of liquid biofertilizer (BF) and the harvest times throughout cultivation. The experiment was carried out in a randomized block design, in a 3x6 factorial with subdivided plot and seven replications. The treatments were foliar and drip BF application and a control, without application of BF, and harvesting time (85; 92; 99; 106; 113; 120 days after transplanting-DAT). Leaf application resulted in a class I production increase in the second week of harvest (92 DAT), while drip application reflected higher class II and III production in the fourth week (106 DAT). In all treatments, at 92 DAT higher production of large fruits (class I) was observed. Production of average fruits (class II) occurred at 92 and 113 DAT and small fruit (class III) production was concentrated at 113 DAT. The adoption of BF, regardless of the application form, provides an increase in total productivity, with an income up to 35% higher. Therefore, biofertilizer is a good source for nutrition implementation aiming at yields and returns in the tomato production chain.

Quality of guava fruits bagged with different materials in an organic system

2020-07-20T22:29:48-03:00

This study aimed to evaluate the interference of bagging materials on the incidence of insect larvae and the physical and chemical quality of the guava cv. Paluma in an organic system. The experimental design was in randomized blocks with seven treatments and four replications of 25 fruits each. The bagging materials (treatments) were: nonwoven fabric (TNT), transparent plastic bag, white plastic bag, parchment paper, kraft paper, and non-bagged fruits (control). The titratable acidity (TA), ascorbic acid, soluble solids (SS), SS/TA ratio, fresh mass, fruit diameter, fruit length, appearance, and fruit fly incidence were evaluated. Fruit bagging increased the fresh fruit mass, except the tulle bag, which did not change fruit diameter but increased fruit length. There was a high incidence of fruit flies in the non-bagged fruits (100%) and in those with tulle bags (56.53%), reduced to 2.15% when using parchment paper, and reaching the absence of bored fruits when using nonwoven fabric, transparent plastic, and white plastic bags, materials that provided the highest percentages of marketable fruits. All bagging materials did not change the total titratable acidity content and the SS/TA ratio; however, all of them reduced the content of total soluble solids, except the tulle bag. Fruit bagging with nonwoven fabric and parchment paper increased the content of ascorbic acid. Fruit bagging with parchment paper, plastic bag, and nonwoven fabric are efficient in the organic production of guavas for preventing the infection by insect larvae and maintaining the physical and chemical quality of the fruit.

Do planting methods and nitrogen management interfere with the economic viability of the melon crop?

2020-07-20T23:42:51-03:00

Proper crop management results in higher profitability and the verification of economic viability is paramount to the definition of the methodologies used. This study aimed to verify the economic viability of seedlings or seeds use, associated with the inoculation with Azospirillum brasilense and nitrogen in topdressing fertilization in Cantaloupe melon production. The experiment was designed in randomized blocks with eight treatments. The treatments were composed of planting methods (seedling or seed), inoculation with Azospirillum brasilense (with or without), and partial application of 120 kg ha-1 of nitrogen as topdressing fertilization (with and without). It was verified that operations and seed acquisition represent the major cost factors. As for treatments, the use of seedling transplants with topdressing fertilization with nitrogen results in an increase of up to 37.01% in fruit production and, consequently, increases the indicators of economic viability. Also, A. brasilense, although not resulting in significantly higher production, raises the profitability. In this way, the seedling transplant, combined with the nitrogen in topdressing fertilization, results in higher profitability, and the use of A. brasilense is a technique with the potential for use in melon cultivation.

Desiccation tolerance of cambuci seeds

2020-07-20T22:43:46-03:00

This work aimed to evaluate the interference of seed desiccation on the occurrence of root protrusion and the formation of normal cambuci seedlings. Seeds were obtained from mature fruits collected from adult plants and submitted to oven drying with forced air circulation at 30±2°C in order to obtain different water contents. The seeds were then submitted to the germination test in a completely randomized design at 25°C and 12 hours photoperiod, and were weekly evaluated for a period of 90 days, regarding the number of seeds with root protrusion, the number of dead seeds and normal seedlings. At the end the germination speed index (GSI) the mean germination time (MGT) and the average speed of germination (ASG) were calculated. Any of these variables were significantly affected until the water content decreased to 14.9%, whereas at 9.1% and 6.6% water contents, there was a significant reduction of root protrusion and GSI, and a higher percentage of dead seeds. Cambuci seeds tolerate desiccation down to 15% water content without losing viability.

Gas exchanges and water-use efficiency of Nopalea cochenillifera intercropped under edaphic practices

2020-07-20T22:47:58-03:00

The Nopalea forage cactus (Nopalea cochenillifera) is the main xerophilic species cultivated in Brazil, highlighted as a compatible biological element with the semiarid environment. However, studies on its physiological aspects are still scarce. In this context, an experiment was performed in the Pendência Experimental Station, belonging to the State Company of Agricultural Research of Paraíba (EMEPA-PB), municipality of Soledade, state of Paraíba, Brazil, aiming to evaluate the gas exchanges and the water-use efficiency of intercropped Nopalea Cochenillifera plants in the soil under different edaphic managements. The treatments were distributed in randomized blocks, with three replications in a 2 × 5 factorial scheme, corresponding to the soil without and with mulch and five types of cultivation of Nopalea forage cactus, in monoculture and intercropped with forage watermelon, millet, sorghum, and buffelgrass. The analyzed variables were: stomatal conductance, transpiration rate, net photosynthesis rate, and internal CO2 concentration, besides the instantaneous water-use efficiency, intrinsic water-use efficiency, and instantaneous carboxylation efficiency. The use of soil mulch satisfactorily increased the photosynthetic rate of the forage cactus; this type of practice can aid in the productive development of the crop in semiarid zones, whereas the intercropping with buffelgrass and forage watermelon stimulated photosynthesis and the water-use efficiency.

Phenology and productive performance of chamomile in sowing dates and spacing between plants

2020-07-20T23:40:59-03:00

The present work has aimed to evaluate phenology and productive performance of chamomile in a subtropical weather region, sown in different dates and spacings in between plants. The experiment took place in Santa Maria – RS with four sowing dates in the year 2017 (18/03, 28/04, 30/06 and 31/08) and seven spacings along plants in rows (5, 10, 15, 20, 25, 30 and 40 cm), spaced 30 cm between each other. Phenological observations were made every two or three days in two plants per portion while also accounting for the number of nodes in the main stem. The harvest of chamomile floral chapters was performed manually from the beggining of flowering and repeated biweekly until plant maturation. Productivity of dry floral chapters as well as content and productivity of essential oils were evaluated. It was established that sowing dates affect the productivity of dry floral chapters, content and productivity of essential oil from cv. Mandirituba chamomile, with the sowings of March 18th and April 28th presenting the highest values for such variables. Increasing the space between plants from the 10 cm line to 40 cm in lines spaced in 30 cm has shown a linear tendency of decreasing the productivity of dry floral chapters. Spacings between plants did not affect the phenological development of chamomile, however, sowing dates interfered in the thermal time of six evaluated subperiods regarding plastochron and the final number of nodes.

Allometry and morphophysiology of papaya seedlings in a substrate with polymer under irrigation with saline water

2020-07-20T22:56:47-03:00

The availability and quality of the irrigation water are among the limitations for the development of agriculture in the semiarid. Aiming at gathering information on these limitations, this work aimed to evaluate the association between a water-absorbing polymer and water salinity in irrigation frequencies, as well as container volumes on the allometric and morphophysiological indices of seedlings of the papaya (Carica papaya) cultivar ‘Sunrise Solo’. The treatments were obtained from the combination between the water-absorbing polymer (0.0; 0.2; 0.6; 1.0, and; 1.2 g dm-3), the electrical conductivity of the irrigation 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 (0.75 and 1.30 dm3) to study the effects of the container volume, distributed in a randomized block design. At 55 days after sowing, the following characteristics were evaluated: ratio between stem height and diameter; ratio between shoot and root dry matter; root density; leaf blade area; ratio between total leaf area and root dry mass; specific leaf area; leaf area ratio; leaf mass ratio; and Dickson quality index. The allometric and morphophysiological indices were damaged by the increase of water electrical conductivity and favored by the application of the polymer and a higher irrigation frequency. In the production of papaya seedlings, a daily irrigation frequency must be prioritized, using containers of 0.75 or 1.30 dm-3, water with electrical conductivity up to 2.6 and 1.9 dS m-1 when irrigated daily or in alternate days, respectively, and 0.6 g dm-3 of polymer.

Controlled-release fertilizer increases growth, chlorophyll content and overall quality of loquat seedlings

2020-07-20T23:04:40-03:00

Eriobotrya japonica (Thunb.) Lindl. (Rosaceae), commonly known as the loquat tree, is widely cultivated due to production of edible fruits, which can be consumed fresh or processed into different food products. Enhancement of loquat seedlings quality is an important issue for more efficient propagation protocols, including rootstock production. The objective with the present study was to assess the effects of increasing doses of controlled-release fertilizer on loquat seedlings growth, quality and chlorophyll content. Seeds were sowed in containers filled with commercial substrate previously treated with different doses of controlled-release fertilizer (N, P, K, Mg, S and micronutrients): 0.0 (control), 2.5, 5.0, 7.5 and 10.0 kg per cubic meter of substrate (kg m-³). Seedlings were evaluated 182 days after sowing and the data were submitted to polynomial regression analyses. Increasing doses of the fertilizer promoted increasing linear behavior on seedlings height, root collar diameter, leaf area, roots and shoots dry mass and Dickson quality index. Chlorophylls a, b and total chlorophylls increased up to the dose of 7.5 kg m-³, followed by a decrease at the dose of 10 kg m-³. The dose of 10 kg m-³ promoted the highest values of Dickson quality index and growing variables on loquat seedlings.

Application strategies of saline water and nitrogen doses in mini watermelon cultivation

2020-07-20T23:08:31-03:00

Salt stress is highlighted as one of the limiting factors for the establishment of agriculture in the semiarid region of Northeastern Brazil. In this context, it is essential to look for new strategies aiming at minimizing the effects of salt stress on the crops. The present work aimed to evaluate the photochemical efficiency, photosynthetic pigments, and growth of the watermelon cv. Sugar Baby under different use strategies with saline waters and nitrogen fertilization. The experiment was conducted in a protected environment at the Center of Technology and Natural Resources of the Federal University of Campina Grande, municipality of Campina Grande, Paraíba. An experimental design in randomized blocks was adopted, arranged in a 6 x 2 factorial scheme, with six management strategies of water salinity and two nitrogen doses (corresponding to 50 and 100% of the recommendation), with five replications. Two salinity levels of the irrigation water were studied, one with low and another with a high level of electrical conductivity of the water (ECw = 0.8 and 3.2 dS m-1). The watermelon cv. Sugar Baby expressed higher sensitivity to salt stress in the flowering phase, with a decrease in the synthesis of chlorophyll b, chlorophyll total, and carotenoids. The 50% dose of N provided an increment in the initial fluorescence, stem diameter, and the number of leaves of the watermelon cv. Sugar Baby. The length of the main branch of the watermelon plants decreased with the salt stress applied in the fructification phase; however, the fertilization with 100% of N stimulated a higher growth when the irrigation with saline waters was performed at the vegetative and flowering phases.

Chemical and mineral characteristics, bioactive compounds and antioxidant activity of blackberries grown in an organic system

2020-07-20T23:11:50-03:00

Blackberry bushes have increasingly drawn producers’ and consumers’ interest since they find their cultivation characteristics, production and nutraceutical qualities advantageous. Both chemical and mineral characteristics, bioactive compounds and antioxidant activity found in blackberries are extremely relevant factors to be considered when cultivars are chosen. Chemical analyses of the nutritional composition of fruit is important, since they can help studies of quality genotypes. Besides, fruit with high nutritional values contribute to human health when they are often consumed. This study aimed at evaluating chemical and mineral characteristics, besides bioactive compounds and antioxidant activity, of different blackberry bush genotypes grown in an organic farming system in Pelotas, Rio Grande do Sul (RS), Brazil. Production, soluble solid content, hydrogenionic potential, total titratable acidity, SS/TA ratio, minerals, phenolic compounds, anthocyanins and antioxidant activity of six blackberry bush genotypes – ‘Tupy’, ‘BRS Xingu’, Selection Black 178, Selection Black 128, Selection Black 112 and Selection Black 145 – were evaluated. It was a randomized block design with three replicates of every plant. Selection Black 178 yielded fruits with the highest value of SS/TA ratio and had the highest accumulated production. The highest anthocyanin content was found in ‘BRS Xingu’. Selection Black 112 had the highest total contents of phenolic compounds and the highest antioxidant activity, whereas ‘Tupy’ exhibited their lowest values. Selection Black 178 adapted well to the organic farming system, a fact that did not happen to Selection Black 128.

Biometrics, physiology, production, and quality of Cantaloupe melons grown with saline waters under semi-arid conditions

2020-07-20T23:20:09-03:00

Brazilian Northeast region emerges as both producer and exporter relevant of cantaloupe melon to several countries; however, this region is vulnerable to salinization problems due to it is inserted in a semi-arid area. This study aimed to evaluate the biometrics, physiological, production and quality of new cantaloupe melon hybrids cultivated with different saline waters under semi-arid conditions. The experiment was conducted using a drip irrigation system in a split-plot randomized design. The plot was different irrigation water electrical conductivity (ECw) levels: 0.5, 2.0, 3.5, and 5.0 dS m-1, while the subplot was two new cantaloupe melon hybrids: Zielo and SV1044. Plant biometrics (stems and leaves analysis), plant physiology (solutes accumulation and gas exchange in leaves), fruit production (number, weight, and yield), and fruit quality (physical and chemical analysis) were investigated. Stem length, leaf numbers, leaf area, and shoot dry mass decreased when ECw increased from 0.5 to 5.0 dS m-1. Also, there was an increase of Na and Cl concentration and reduction of K concentration in leaves due to ECw increase. Gas exchange reduction, losses in fruit numbers, weight, yield, and in quality were observed with the ECw increase. It is possible to conclude that the ECw increase salinizes the soil and increases Na and Cl concentration in plants causing reduction in gas exchange, in growth, and in fruit production and quality. However, the response of cultivated hybrids regarding salinity may be different, as in our study that the Zielo hybrid was less affected by the increase in ECw.

Antibiotic resistance profile of local thermophilic Bacillus licheniformis isolated from Maysan province soil

2020-07-22T17:53:52-03:00

The key concern for public health is that bacterial strains isolated from various ecosystems are immune to antibiotics used in human medicine, thus dramatically limiting therapeutic options and threatening the lives of infected people. The present study aims to reveal the antibiotics profile of fiftysix isolates of local thermophilic Bacillus licheniformis isolated from different environmental soil sites in Maysan city, Iraq. The antimicrobial agent resistance profile of B. licheniformis isolates was performed using the disc diffusion assay according to Kirby-Bauer susceptibility test protocol. The results showed that isolates were resistance against cefepime (n=56; 100%), amoxicillin (n=13; 23.3%) and ampicillin (n=52; 92.9%); and intermediate (n=56; 100%) against cephalothin and naldixic acid. The percentage resistance was low for aztreonam (n=4; 7%), chloramphenicol (n=3; 5%), clotrimazole (n=6; 10%), novobiocin (n=2; 3.5%) and ticarcillin (n=3; 5%). On the other hand, all isolates were sensitive (n=56; 100%) towards the following antibiotics: amikacin, ceftazidime, ciprofloxacin, clindamycin, imipenem, netilmycin, gentamicin, nitrofurantion, rifampin, trimethoprim and vancomycin. The results of this study suggest that the Iraqi thermophilic B. licheniformis isolates are variable in their susceptibility towards the standards antimicrobial agents. Furthermore, the presence of cefepime, amoxicillin, ampicillin, cephalothin and naldixic resistant isolates of B. licheniformis in Iraqi soils is of concern about how resistance could spread to other bacteria, and ultimately to humans.

Estimation of the genetic diversity of jabuticaba trees and association among fruit characters

2020-07-20T23:29:16-03:00

The aim of this study was to evaluate the genetic dissimilarity of different jabuticaba tree accessions from Prudente de Moraes, Minas Gerais State, Brazil, based on fruit characters. The genetic diversity study was carried out based on characters evaluated in fruits, and with the elimination of redundant descriptors, nine characters were selected to estimate genetic divergence and perform clustering. The Standardized Mean Euclidian Distance was used as dissimilarity measure. The clustering methods used were Tocher and the nearest neighbor. Correlation analysis among characters was performed by Pearson correlation (p> 0.05). Accessions 4, 5, 7 and 12 have potential for in improvement programs aiming for productivity. The character that contributed most to the genetic diversity of the accessions were the soluble solids important for the processing industry and for fresh consumption. Genotypes showed variability for most characters analyzed showing the possibility of selection and identification of parents that will be used in future crossings.

Phytomass and quality of yellow passion fruit seedlings under salt stress and silicon fertilization

2020-07-20T23:32:20-03:00

The semiarid region of Northeastern Brazil is characterized by long drought periods, and the use of saline waters appears as an alternative for the expansion of irrigated areas. Associated with the use of these waters, silicon fertilization constitutes an important attenuator of salt stress. In this perspective, this study aimed to evaluate the phytomass production and quality of the passion fruit cultivar ‘Gigante Amarelo’ grown with saline water and silicon fertilization. The experiment was conducted in a plant nursery belonging to the Center of Agrifood Science and Technology, in the municipality of Pombal-PB. A completely randomized block design in a 5 x 5 factorial scheme was used, referring to five levels of electrical conductivity of the irrigation water (0.3, 1.0, 1.7, 2.4, and 3.1 dS m-1) and five doses of silicon fertilization (0; 25; 50; 75, and 100 g of potassium silicate/plant), with four replications and two plants per plot. The phytomass accumulation (leaves, stem, and roots), as well as the total dry phytomass, shoot dry phytomass, root/shoot ratio, and the quality index of Dickson were evaluated. The data obtained were subjected to the F-test at 0.01 and 0.05 level of probability. The electrical conductivity of water from 0.3 dS m-1 caused the decrease of phytomass production in seedlings of the passion fruit cultivar ‘Gigante Amarelo’, although it is possible to produce good quality passion fruit seedlings with water salinity up to 3.1 dS m-1. The doses of silicon fertilization mitigated the effect of salt stress on the root/shoot ratio of plants of the passion fruit cultivar ‘Gigante Amarelo’.

Grafting methods and use of fasteners in monoembryonic, polyembryonic, and multi-stemmed jaboticaba (Plinia jaboticaba (Vell) Berg) seedlings

2020-07-01T15:52:14-03:00

Jaboticaba is a native fruit from Brazil, appreciated for its sweet taste and organoleptic characteristics. The propagation of this fruit species occurs exclusively through seeds, which present high germination rates, although with a long period of juvenility, a fact that favors advances in studies aiming at an early fruiting. This research aimed to study a more adequate and rapid grafting method for the jaboticaba cv. Sabará. The experimental design was in randomized blocks, with 12 treatments consisting of combinations using three types of seedlings (monoembryonic, polyembryonic, and multi-stemmed), two grafting methods (top cleft and splice grafting), and two fasteners (parafilm® tape and circular clip), with three replications consisting of 10 seedlings each. The analyzed characteristics were: monoembryony (%); polyembryony (%), multi-stemming (%), grafting success rate (%), survival (%), scion length (cm), scion diameter (mm), and rootstock diameter (mm). The percentage of monoembryony (46.4%) was higher than the success rates of polyembryony (36%), and multi-stemming (17.6%). The top cleft grafting method of monoembryonic seedlings fastened with parafilm® and circular clip, and polyembryonic seedlings fastened with circular clip were the more suitable for grafting in the jaboticaba cv. Sabará.

Three species of Colletotrichum are associated with anthracnose of pomegranate in Brazil

2020-07-13T17:51:36-03:00

Pomegranate is a fruit rich in vitamins and secondary metabolites used in traditional medicine and industry. However, production losses have been associated the anthracnose, disease caused by Colletotrichum species. This is an important disease of the pomegranate, as it affects the yield and the quality of the fruits. The present study aimed to investigate which species of Colletotrichum are associated with anthracnose disease in pomegranate in the Northeast region of Brazil, using multi-locus phylogenetic analysis and morpho-cultural characteristics. The total DNA extracted was amplified with GAPDH, TUB2, CAL, ACT genes and the ITS-rDNA region. The sequences obtained were used for the construction of phylogenetic trees of Bayesian inference. The mycelial growth rate, size and shape of the conidia and appressories were evaluated for the morpho-cultural characterization of the species. Six isolates were analysis and three species belonging to the C. gloeosporioides complex were identified in this study. This is the first report of C. theobromicola (2) in pomegranate fruit in Brazil and C. siamense (2) and C. fructicola (2) in the world.

Bioregulators on seed germination and seedling growth of sweet basil

2020-07-13T17:51:18-03:00

Basil (Ocimum basilicum L.) plants have multiple uses, ranging from spice to cosmetic purpose, besides being a source of essential oil and aromatic. These plants were commonly propagated by seed, however, few agrotechnologies are used to enhance the seed germination and initial growth in this crop. For this reason, our research aimed to evaluate aspects of seed germination of Ocimum basilicum L. cv. Limoncino, subjected to different bioregulators applied via substrate imbibition. The experiment was carried out in completely randomized design, with four treatments, as follows: T1: control (distilled water), T2: T13 a solution of a product formulated based on indolbutyric acid + naphthalene acetic acid + gibberellic acid (0.2 mL L-1, Liko Química), T3: gibberellic acid (0.5 mM L-1, progibb-400®) and T4: brassinosteroids (0.1 mM L-1). We evaluated: germination rate, germination speed index (GSI), first count, root and shoot length and chlorophyll a, b, total and carotenoids. The bioregulators did not influence germination, first count, GSI and photosynthetic leaf pigment, but application of gibberellic acid and brassinosteroids improve the shoot and root length, respectively. The gibberellic acid and brassinosteroids are promising bioregulators for stimulating initial basil growth.

In vitro germination of pollen grains of three native species from Pampa biome with ornamental potential

2020-07-13T17:51:06-03:00

The aim of this work was to verify the in vitro germination of pollen grains of Angelonia integerrima L., Campomanesia aurea O. Berg and Sesbania punicea (Cav.) Benth in different culture medium and temperatures. For this purpose, flower buds from which pollen was collected and sprayed on plates containing the three evaluated culture medium: M1 - agar and sucrose; M2 - agar, sucrose and H3BO3; M3 - agar, sucrose, H3BO3, Ca(NO3), MgSO4 and KNO3; and two incubation temperatures (20 °C and 30 °C). Data was subjected to analysis of variance after its transformation to square root and means were compared by Fisher’s test (LSD). For the three species, the temperature of 30 ºC provided the highest percentage of pollen grain germination. For A. integerrima, M1 and M3 promoted the highest germination percentages (40.7 % and 56.5 %, respectively). On the other hand, for C. aurea, M2 provided the highest germination average (43.7 %). At last for S. punicea, M3 was the one that provided the highest average (31.62 %). It was concluded that the evaluated species differ in micronutrient requirements for in vitro germination of pollen grains. The temperature of 30 °C was suitable for all three species.