Comunicata Scientiae

Ornamental potential of species from the ferruginous Campo rupestre of the Carajás National Forest, Brazilian Amazon

2021-02-08T15:05:33-03:00

The flora of the ferruginous Campo rupestre that occur over the immense iron deposits of the Carajás National Forest is very unique, with several endemic and rare species. This vegetation is directly affected by mining activity, as a result of vegetation suppression and the profound disfigurement of habitats. The objective of this work was to identify the ornamental potential of the flora of the ferruginous Campo rupestre, as a strategy for ex situ conservation of ecosystem species. The species present in ten plots of 5 x 5 m were surveyed in different areas of the ferruginous Campo rupestre on the N1 plateau and the ornamental potential of each species was evaluated following a characterization key, considering morphology and habitat of occurrence. Subsequently, the species were compared with those already present on the market, as ornamental, based on the literature and on sites specialized in the sale of ornamental plants in Brazil. A total of 33 species with ornamental potential were found, distributed in 32 genera and 19 families. Most species showed high functionality for ornamentation and similarity with nationally consolidated ornamentals. Catasetum planiceps, Cyrtopodium andersonii, Epidendrum nocturnum, Mandevilla scabra, Norantea guianensis and Sobralia liliastrum have a consolidated ornamental market. The data collected support ex situ conservation strategies of the flora of the ferruginous Campo rupestre, such as its valorization, local commercialization and income generation for small extractivists in the region.

Methods of applying hydrogen peroxide to soursop seedlings irrigated with saline water

2021-02-08T15:05:30-03:00

The acclimatization of plants to salt stress, through the application of hydrogen peroxide, occurs due to the activation of the antioxidant defense system. In this sense, the aim of the study was to evaluate the levels of photosynthetic pigments and the photochemical efficiency of soursop seedlings under irrigation with saline water and different methods of applying hydrogen peroxide. The study was carried out in greenhouse conditions, in a 5 x 4 scheme, with five levels of electrical conductivity of irrigation water - CEa (0.6; 1.2; 1.8; 2.4 and 3.0 dS m^-1) and four methods of application of hydrogen peroxide-MA (without application of H2O2, application via seed soaking, application via leaf spray and application via seed soaking and leaf spray). The salinity of irrigation water up to 1.4 and 1.1 dS m^-1 caused an increase in the synthesis of chlorophyll b and carotenoids, respectively. Irrigation with water from 0.6 dS m^-1 reduced the synthesis of chlorophyll a and total of soursop plants. The application of 20 μm of H2O2 via seed imbibition results in an increase in the contents of chlorophyll a and b, total, maximum and variable fluorescence of soursop seedlings. Soaking the seeds with hydrogen peroxide increased the initial fluorescence of chlorophyll in plants irrigated with water 1.2 dS m^-1.

Growth and nutritional diagnosis of Rosemary plants submitted to nitrogen and sulfate fertilization

2021-02-08T15:05:36-03:00

Studies on the cultivation of medicinal plants are of relevance to the population since they are primary sources of medication. Among these plants stands out the rosemary (Rosmarinus officinalis L.) for having diverse therapeutic properties. The objective of this work was to evaluate the initial growth and nutritional status of rosemary plants grown with different co’ncentrations of nitrogen and sulfur. The treatments were distributed in a 4x2 factorial scheme with four nitrogen doses: 105, 210, 315, and 420 mg L-1 of nitrogen combined with two sulfur doses: 32 and 64 mg L-1 with seven replications totaling 56 experimental units. The seedlings were obtained through asexual propagation (cuttings), originating from parent plants. The experimental units were arranged in a completely randomized design. Growth evaluations were carried out at 120 days of cultivation, using: plant height (HT) stem diameter (DS), root dry matter mass (RDM), stem dry matter mass (SDM), mass leaf dry matter (LDM), total dry matter (TDM), shoot dry matter mass (SDMS). The data obtained were subjected to analysis of variance and depending on the level of significance in the F test, the study was carried out using the means test (Tukey 5%). The agronomic characteristics (HT), (DS), (RDM) and (MDMAP) were significant for N. Only (RDM) showed significant interaction for the doses of N and S. The dose 420 mg L-1 promoted the highest concentrations in the components leaf and stem. The lowest dose 105 mg L-1, N promoted the highest concentrations of S in the leaf and stem. The assimilation of S by the rosemary plants was dependent on the doses of N.

Stability and adaptability of sweet orange using mixed models

2020-12-29T15:06:18-03:00

Evaluations with sweet oranges are usually performed in several harvests and places to verify the differential behavior according to the environmental variations. This makes the selection by traditional statistical methodologies more and more difficult since they have limitations in the case of data unbalanced, common in citrus during the experimental phase due to the possibility of plot loss over the years. The objective of this work was to estimate the temporal stability and adaptability of sweet orange genotypes cultivated in eight crops under the edaphoclimatic conditions of Rio Branco, Acre. The experimental design used was in randomized blocks containing 55 genotypes and three replications. Four agronomic characteristics were evaluated during eight harvests. The genetic parameters were estimated using the REML/BLUP methodology. After detecting the presence of significant interaction between genotypes and environments, stability and adaptability analyzes were conducted by the methods of the harmonic mean of the genotypic values (HMGV), the relative performance of the genetic values (RPGV) and the harmonic mean of the relative performance of the genotypic values (HMRPGV). The HMRPGV can be used to select stable, adapted and productive sweet orange genotypes. The number 48, 19, 5, 14, 2, 47 and 37 sweet orange genotypes can be selected for cultivation in an environment similar to the one studied, as they simultaneously present high stability, adaptability and productivity.

Morphophysiology of the passion fruit ‘BRS Rubi do Cerrado’ irrigated with saline waters and nitrogen fertilization

2021-02-08T15:05:28-03:00

This study aimed to evaluate the gas exchanges and growth of the purple passion fruit cultivar ‘BRS Rubi do Cerrado’ as a function of the salinity levels of the irrigation water and nitrogen fertilization. The research was conducted in pots adapted as drainage lysimeters, placed within a plant nursery, using a Regolithic Neosol of sandy texture, in the municipality of Pombal-PB, Brazil. A randomized block design was used, testing five levels of electrical conductivity of irrigation water (0.3, 1.1, 1.9, 2.7, and 3.5 dS m-1) associated with four doses of nitrogen (50, 75, 100, and 125% of the recommendation). The irrigation water salinity above 0.3 dS m-1 compromised the leaf area and the relative water content of the purple passion fruit ‘BRS Rubi do Cerrado’. High doses of nitrogen enhance the deleterious effects of irrigation water salinity on stomatal conductance, transpiration, internal CO2 concentration, CO2 assimilation rate, number of leaves, stem diameter, and height of purple passion fruit plants. When waters with salinity levels of up to 1.3 dS m-1 are used, the dose of 125 mg of N kg-1 of soil is recommendation for providing increases in the CO2 assimilation rate of the purple passion fruit ‘BRS Rubi do Cerrado’ at 70 days after sowing (DAS). Water salinity increases electrolyte leakage, regardless of nitrogen doses.

Concentrations of indolebutyric acid on air-layering of guava cv. Paluma

2021-02-08T15:05:26-03:00

Nowadays, the predominant technique for the commercial propagation of guava seedlings is through cuttings, using herbaceous cuttings that need a specialized infrastructure with intermittent misting, clean water, exhausters, water filters, and fans. As an alternative to plant propagation by cuttings, this study aimed to evaluate the influence of concentrations of indolebutyric acid (IBA) on the rooting of branches of the guava cv. Paluma by air-layering. The experimental design was in randomized blocks, with four replications and 10 air layers per plot. The treatments consisted of six concentrations of IBA powder mixed with industrial talcum: 0, 1,000, 2,000, 3,000, 4,000, and 5,000 mg.kg-1. Four adult guava parents that were in the off-season period were used. For the preparation of the air layers, the stems were girdled with a 4.0 cm width, using a steel blade, by removing the bark until exposing the cambium region, followed by IBA application and wrapping of the branches with a plastic bag containing moist organic substrate. The following variables were evaluated 120 days after air-layering: percentage of rooted and callused air layers, longest root length, and root dry matter. The analysis of variance indicated no significant differences between the IBA concentrations for all variables, but the rooting percentages were high (68.6 to 92.2%) regardless of the application of the exogenous auxin.

Fruit quality of Tahiti acid lime and Sicilian lemon trees grown on different rootstocks and spacings in the semi-arid region

2021-03-14T21:01:54-03:00

The objective of this work was to evaluate the fruit quality of Tahiti acid lime and Sicilian lemon trees grown
on different rootstocks and planting spacings in the semi-arid region of the state of Minas Gerais, Brazil. Two
experiments were conducted, using Tahiti acid lime tree scions (Citrus latifolia Tanaka) (1) and Sicilian lemon
trees scions [Citrus limon (L.) Burm] (2). A randomized block design was used, with a 6×2 factorial arrangement consisted of six rootstocks: Cravo Santa Cruz lemon (Citrus limonia Osbeck), Swingle citrumelo [Citrus paradisi Macfaden × Poncirus trifoliata (L.) Rafinesque], Indio citrandarin and Riverside citrandarin [Citrus sunki (Hayata) hort. ex Tanaka × Poncirus trifoliata (L.) Rafinesque], Hybrid TSKC × (LCR × TR) - 059 [Citrus sunki (Hayata) hort. ex Tanaka × (Citrus limonia Osbeck × Poncirus trifoliata (L.) Rafinesque)], and Sunki Tropical tangerine [Citrus sunki (Hayata) hort. ex Tanaka]; and two planting spacings: 6.0 × 4.0 m and 6.0 × 2.0 m, with three replications and four plants per plot. The physical and chemical characteristics of fruits were evaluated. Most quality characteristics of Tahiti acid lime and Sicilian lemon are not affected by the different rootstocks and spacings used, but the fruits present excellent quality for the national and international markets. Tahiti acid lime plants grown on less vigorous rootstocks under denser spacings have fruits with higher pH, whereas those grown on more vigorous rootstocks have fruits with thicker mesocarps and lower soluble solid contents. The use of Sunki Tropical tangerine rootstock results in bigger Sicilian lemons, however, with lower soluble solid contents, whereas an opposite result is found with the use of Swingle citrumelo rootstocks.

Water content of pomegranate seeds subjected to storage and packaging periods

2021-03-14T21:03:32-03:00

The worldwide demand for unconventional fruits, such as pomegranate (Punica granatum L.), has been growing due to their nutraceutical characteristics. Given the social and industrial importance of the crop, information about the seed storage conditions should be elucidated to technify its cultivation. The objective of this work was to evaluate, by determining the water content, the behavior of pomegranate seeds when stored in different periods and packages. The seeds were separated into 2 lots: seeds with sarcotesta and for another lot, seeds without sarcotesta. The storage periods used were: 0, 30, 60, 90 and 120 days, in 3 types of packaging (polyethylene, paper bags and glass bottles), which were stored in BOD at 5±0.2ºC and relative humidity 35±2%. After storage periods, the seed water content was evaluated. Throughout storage periods, polyethylene containers reduced the water content of seeds with and without sarcotesta. Paper bags did not preserve the water content of both types of pomegranate seeds. The water content of pomegranate seeds with and without sarcotesta was better conserved when glass containers were used for storage.

Are biomass partitioning and nutrient accumulation in industrial tomato influenced by NPK fertilization?

2021-03-14T21:13:16-03:00

This study aimed to evaluate the uptake, accumulation, and partitioning of nitrogen (N), phosphorus (P), and potassium (K) in the tomato crop fertilized with doses of NPK. The main plots consisted of three doses of N: 90, 135, and 180 kg ha-1, P: 270, 405, and 540 kg ha-1, and K: 225, 337, and 450 kg ha-1 (equivalent to 50, 75, and 100 % of the fertilization recommendation for industrial tomato), while the subplots consisted of the evaluation periods: 20, 40, 60, 80, and 100 days after transplanting (DAT). The dry matter and the accumulation of N, P, and K were characterized in the different plant components (leaves, stems, fruits, and total). The order of nutrient uptake for the hybrid BRS Sena was defined as K> N> P. The dose corresponding to 50 % NPK resulted in the maximum accumulation of total dry matter of 400 g per plant at 64 DAT and the total accumulation of 10, 1.14, and 14.51 g per plant of N, P, and K, respectively. The intermediate dose of NPK resulted in the maximum accumulation of total dry matter of 468 g and accumulations of 14, 1.6, and 19 g per plant of N, P, and K. At 100 % of the NPK recommendation, there was 514 g per plant of total dry matter, with maximum accumulations of 15, 1.6, and 18 g per plant of N, P, and K. The maximum accumulation rate of N, P, and K occurs at 60, 64, and 70 DAT for the fertilization recommendations corresponding to 50, 75, and 100 % NPK, respectively.

Postharvest conservation of ‘Sunrise Solo’ papaya under cassava starch coatings added with ginger essential oil

2021-03-14T21:17:48-03:00

The use of biodegradable coatings associated with essential oils with fungicidal action can be an efficient alternative in the conservation and reduction of postharvest losses of papaya, a very perishable fruit susceptible to decay. In this sense, the objective of this work was to evaluate the postharvest conservation of papaya under cassava-based starch biodegradable coatings, added with essential oil (EO) of ginger. The experimental design was the completely randomized in a split-plot scheme, with the plot consisting of 5 coatings applied to ‘Sunrise solo’ papaya’ harvested in the light green maturity stage: (control (without coating); 2% cassava starch (S2%); S2% + 0.15% ginger essential oil (EO); S2% + 0.30% EO and S2% + 0.45% EO) and in the subplot the days of storage: (0, 3, 6, 9 and 12 days), with 4 replications. Papaya coated with S2% + 0.30% EO showed a delay in color evolution, lower weight loss, maintained the levels of soluble solids and ascorbic acid, in addition to reducing the incidence of decay and increasing the purchase intention, thus increasing postharvest life in 4 days as related to control fruits. The use of 2% starch coating added with 0.30% ginger essential oil is a viable, sustainable and low-cost alternative for maintaining the quality and adding value to ‘Sunrise solo’ papaya as a clean technology.

Analysis of baculovirus spodoptera virulence in fall armyworm fed with cassava leaves

2021-03-14T16:39:27-03:00

The fall armyworm, Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae) is considered the main pest of corn (Zea mays L.) in Brazil and feeds on several other plant species, including cassava (Manihot esculenta Crantz). The food substrate influences the control efficiency of baculovirus and there aren’t studies on the effects of the application of baculovirus Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) on cassava leaves in the mortality of S. frugiperda larvae. The main objectives of this study were to evaluate the efficiency of SfMNPV isolate 6 on S. frugiperda larvae fed on corn and cassava leaves. The food substrates were treated with three baculovirus concentrations (2 x 10⁵, 2 x 10⁶ and 2 x 10⁷ OB mL^-1) of a semipurified suspension, and of a commercial formulation (CartuchoVit^®), both containing SfMNPV isolate 6, and then were offer to S. frugiperda second instar larvae. The semipurified virus was more virulent than the commercial formulation, regardless of the food substrate provided to insects, when concentrations of 2 x 10⁵ and 2 x 10⁶ OB mL^-1 were used. However, there was no difference between treatments when baculovirus suspension of 2 x 10⁷ OB mL^-1 was use and the mortality rates were higher than 91%. The mortality was higher when the larvae fed on cassava leaves treated with SfMNPV. Therefore, the food substrate increased the efficiency of SfMNPV, which promises the use of this virus in the management of S. frugiperda in cassava crops.

Physiological and biochemical indicators of Physalis angulata L. plants submitted under salinity

2021-03-14T20:56:11-03:00

Saline environments may limit the growth and yield of agricultural crops, mainly in arid and semiarid regions, causing negative impacts to the plant physiology. Therefore, the objective of this work was to evaluate the growth and physiological and biochemical indicators of Physalis angulata L. plants grown in hydroponic nutrient solutions with different salinities. The experiment was conducted in a greenhouse in a floating hydroponic system, using a completely randomized design. The treatments consisted of five levels of electrical conductivity (EC) of the nutrient solution (EC0 = 0.00 – Control; EC1 = 1.80; EC2 = 3.60; EC3 = 5.40; and EC4 = 7.2 dS m-1). Plant gas exchanges, water relations, total chlorophyll contents, organic solute accumulation, and growth parameter were evaluated at 35 days after the application of the treatments. The salinity of the nutrient solution had significant effect on the variables analyzed, denoting adaptation of the plants up to the EC of 2.10 dS m-1.
Decreases in photosynthetic rates at the highest salinity levels affected the plant growth, causing pronounced decreases. The P. angulata plants showed osmotic adjustment after the induction of a severe salt stress at 35 days after sowing; they accumulated organic solutes that increased leaf turgidity, even at lower salinity levels, maintaining the plant water status.

Summer squash morphophysiology under salt stress and exogenous application of H2O2 in hydroponic cultivation

2021-03-14T21:31:14-03:00

Summer squash is a vegetable of significant acceptance in the market due to its economic and nutritional
importance, with the potential for expansion in the food industry. In this context, this study aimed to evaluate the gas exchange and growth of summer squash plants subjected to a saline nutrient solution and exogenous application of hydrogen peroxide. The study was conducted in a greenhouse in Pombal – PB. The cultivation system used was the Nutrient Film Technique (NFT) hydroponic system. The experimental design was completely randomized, in a 4 x 4 factorial arrangement, whose treatments consisted of four levels of electrical conductivityof the nutrient solution - ECns (2.1, 3.1, 4.1, and 5.1 dS m-1) and four concentrations of hydrogen peroxide – H2O2 (0, 20, 40, and 60 μM), with three replications. The increase in the nutrient solution salinity from 2.1 dS m-1 reduced the leaf area and transpiration of the summer squash plants. Hydrogen peroxide at a concentration of 40 μM increased the root length, the instantaneous carboxylation efficiency, and the CO2 assimilation rate when the plants were subjected to the saline solution of 2.1 dS m-1. Also, the application of 60 μM H2O2 mitigated the effect of salt stress on the internal CO2 concentration and stomatal conductance of the summer squash plants.

Cytokinins induce the development of Campomanesia pubescens root cuttings

2021-03-15T16:40:13-03:00

The gabirobeira (Campomanesia pubescens) is a species native to Brazilian Cerrado with great potential but is threatened to extinction and remains wild. The nursery plant production is an alternative to solve those problems and the use of plant growth regulators can support vegetative propagation. The objective of this work was to evaluate the effect of cytokinin concentrations on the vegetative propagation of C. pubescens root cuttings. The concentrations of the cytokinin 6-Benzylaminopurine were: 0.0 (Control), 1.0; 2.0 and 4.0 mg L^-1 diluted in NaOH solution (6 mol L^-1). The cuttings with standard size of 5 cm were dipped in the concentrations for 15 seconds and transplanted in bags containing the substrate Bioplant. After 140 days the number of shoots, length of the shoots, number of leaves, length of the leaves, the diameter of the main stem, the diameter of the main root, the total number of roots, length of the main root, total fresh matter and total dry matter, were evaluated. The experiment was conducted in a completely randomized design, with fifteen replicates per treatment. The data were submitted to analysis of variance and the effects of the concentrations tested and adjusted by regression equations. The lower concentrations of cytokinin were beneficial to the development of the cuttings, while higher concentrations inhibited their development.

Selection of genotypes with ornamental potential in an F4 population of ornamental peppers (Capsicum annuum L.) based on multivariate analysis

2021-03-15T16:39:52-03:00

Abstract: The commercialization of ornamental pepper plants has been growing in the national and international floriculture markets. In spite of this growth, there are still few available cultivars for ornamental purposes, suggesting a need for improvement programs in this segment. Given the exposed, this work aimed to select genotypes with ornamental pepper potential using multivariate analysis. The work was performed in a plant nursery at the Campus of Agricultural Sciences of the Federal University of Paraíba (UFPB). One segregating F₄(17.15) population was used, analyzing 16 qualitative and quantitative morphological descriptors. The experimental design was completely randomized. 45 plants belonging to an F₄ segregating population were evaluated. Singh’s criterion was adopted to quantify the relative contribution of the characteristics. Afterward, Tocher’s clustering method based on the generalized distance of Mahalanobis was used for the quantitative variables. Gower’s distance was employed for the qualitative variables, and afterward, a joint analysis with qualitative and quantitative data was performed, using the sum of distances of both types of variables. Furthermore, a non-metric multidimensional scaling was applied. Based on qualitative traits 14 clusters were formed. Multidimensional scaling based on quantitative traits the most divergent genotypes were 17, 12, 36, 23, and 19. According to the analysis performed the genotypes 12, 16, 19, 15, 29, 41 and 44 are indicated to open line in F5 generation.

Keywords: diversity, gower, Mahalanobis, ornamental plants

Tank mixture of pesticides for Tuta absoluta and Neoleucinodes elegantalis control in tomato crop

2021-03-15T16:39:30-03:00

The use of pesticides in tank mixtures is important to reduce application costs and increase pest control, mainly. The objective of this study was to evaluate the influence of manganese foliar fertilizers on the effectiveness of the chlorantraniliprole (Chlt) to control tomato leaf miner and tomato fruit borer in tomato crop and to evaluate the possible effects of these mixtures on plant physiology. The experiment was conducted in a greenhouse, on randomized block design with eight treatments and four replications each. The treatments were: 1 – Chlt; 2 – Chlt + MnSO₄; 3 – Chlt + Mn(NO₃)₂; 4- Chlt + Break-Thru (BTH); 5 - Chlt + MnSO₄ + BTH; 6 – Chlt + Mn(NO₃)₂ + BTH; 7 – Chlt + MnSO₄ + Mn(NO₃)₂ + BTH; 8 - Control. The physical chemical properties, physiological effects, pesticide efficacy and yield were evaluated. The results showed that the use of chlorantraniliprole in mixture with adjuvant and foliar fertilizers did not influence its efficacy against Tuta absoluta and Neoleucinodes elegantalis. Also, the mixture did not influence the chlorophyll content and all the nutrients content were in appropriate levels. We conclude that tank mixture with manganese foliar fertilizers do not have influence over the efficacy nor the physiological characteristics. The physical chemical evaluations changed according to each manganese salt add in the mixture.

Growth and initial development of passion fruit plants in different concentrations of biostimulants

2021-03-15T16:39:09-03:00

The objective of this research was to evaluate the vegetative growth of yellow passion fruit seedlings, propagated by seeds, regarding the rates of use and application of two biostimulants in two types of soil. The experiment was carried out at the State University of Piauí (UESPI) / Campus de Corrente, with Passiflora edulis as a research culture, on a 50% brightness screen. The completely randomized design consisted of four treatments arranged according to the following application doses (0, 4, 8, 12 and 16 mL), using the biostimulant Solofull® and Stimulate® via soil, with six replicates per treatment, totaling 24 units experimental. The soil used came from two situations, soil 1 (area in the process of degradation, Gilbués - PI) and soil 2 (pasture area, Corrente, PI). At 65 days after sowing, height, stem diameter, number of true leaves, leaf area, plant height ratio and stem diameter and root length were evaluated. The data were submitted to analysis of variance. The application of the Stimulate® biostimulant in seedlings produced in soil cultivated by pasture, promoted the best development of the aerial and root system of the plants.

Incubation period and fungi identification in seeds of Salvia hispânica L.

2021-03-15T16:38:48-03:00

Seed sanitary quality is an essential factor in crop success, and through the evaluation of fungi contamination of seeds, measures can be adopted to control and avoid the transferability of this contamination to the plants. Equally important is the method used to verify the occurrence and identify the species, especially when it comes to crops that have not yet been studied, such as chia, which has a mucilaginous layer that may present some interference in the development of fungi. This study's objective was to identify the genera of fungi present in lots of saved chia seeds, define the best period for their evaluation and its transmissibility to the plantlet. Eight lots from saved seeds of chia were analyzed into two evaluations at seven and 14 days of incubation via the Blotter test method, in which fungi were identified by their reproductive structure using a stereomicroscope. Besides, the transmissibility rate from seed to plantlet of the most incident fungus was evaluated, through the direct isolation method. All estimated seed lots of chia showed fungi contamination, with emphasis on Fusarium sp., Phomopsis sp., Penicillium sp., and Aspergillus sp. The best evaluation period to Phomopsis sp. its at 14 days of incubation by the Blotter test method. The genus Fusarium sp. presents a high transmissibility rate from seed to plantlet.