ABSTRACT Plants synthesize specialized metabolites to defend themselves against pathogens. These active compounds, when isolated and identified, can be used as template for fungicide development. Based on field observations, Heteranthera reniformis (kidney leaf mudplantain) could potentially synthesize compounds with antifungal activity. The goal of this study was to evaluate the fungicidal activity of H. reniformis leaf extracts on Bipolaris oryzae development. The activities of hexane, ethyl acetate, and methanol extracts of H. reniformis leaves were tested on mycelial growth, sporulation, and colony morphology. Due to the highest inhibition of B. oryzae sporulation, methanol extract was chosen for concentration tests. The effect of methanol extract on B. oryzae spore length and germination was also evaluated. Methanolic extract was the most active in inhibiting B. oryzae sporulation. The morphology of the colonies is altered when the fungus grows in medium containing H. reniformis leaf extracts. Higher concentration of methanol extract stimulates mycelial growth and suppresses B. oryzae sporulation. There are reductions in length and number of germinated B. oryzae spores caused by methanol extract of H. reniformis leaves. Methanolic extract has compounds with antifungal activity and should be subjected to bioassay-guided isolation for purification and identification of these active compounds.

ABSTRACT Gypsum is widely used in agriculture to supply nutrients to the soil-plant system. However, the excessive use of gypsum may lead to a reduction of cationic soil nutrients such as potassium in the most superficial soil layer. Thus, the objective of this study was to evaluate the feasibility of using gypsum and potassium for cauliflower crop nutritional status and commercial production. The experiment was conducted in 5×5 factorial scheme, corresponding to five K doses (0, 100, 180, 240, 360 kg ha−1 of K2O) and five gypsum doses (0, 500, 1000, 2000, 4000 kg ha−1) in dystrophic Red Latosol. Leaf N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn contents, commercial head mass, diameter and height and peduncle diameter were evaluated. The application of 360 kg ha−1 of K2O resulted in 29.69% more K in cauliflower leaf and 18.94% more commercial head mass compared to the non-application of K. The application of 4000 kg ha−1 of gypsum resulted in reductions of leaf S and Mn and increase in leaf Cu. Based on the results observed, 4000 kg ha−1 of gypsum and 360 kg ha−1 K2O could be required for high cauliflower production.

ABSTRACT Studies that allow the estimation of evaporation in reservoirs represent an important action for the adequate management of water resources. Thus, this study aimed at estimating evaporation in the tropical reservoir Gavião, located in the municipality of Pacatuba, Ceará, Brazil, and to verify the effect of these estimates on the water availability of the reservoir using the VYELAS model. The results of Penman's methods and the Water Balance were compared with the values obtained from the hydrostatic pressure sensor, the most accurate. It was possible to verify that, in relation to the pressure difference method, all the conventional methods overestimate the evaporation in the reservoir. The method that presented estimates closer to those obtained by the pressure difference sensor was that of Penman, based on data from an onboard station in the lake, with a deviation of only 12%. The method of water balance also presented reliable results for monthly average. The two methods usually accepted in the evaporation calculation (water balance ignoring the infiltration; and Penman's method for meteorological station data on land distant from the lake) presented the most disturbing evaporation values significantly altering the water availability. The results of the VYELAS model showed that evaporated flows, estimated by several methods, exceeded the reference flow by up to 83%. The results demonstrate the great sensitivity of the estimate of water availability in relation to the evaporation rate in the lake.

ABSTRACT This study aimed to assess the physical, chemical, and sensory attributes of mango varieties grown under the organic farming. Fruits from ten varieties of mango grown under the organic system in the Chapada Diamantina region, BA, Brazil, were assessed. The following physical and chemical characteristics were assessed: fruit mass, pulp yield, pulp color (L*, C*, and h*), soluble solids (SS), titratable acidity (TA), total carotenoids, and ascorbic acid. The sensory acceptance test was performed with 50 consumers using the nine-point structured hedonic scale and the attributes acidity, sweetness, and firmness of the pulp were assessed using the just-about-right scale. Differences among the varieties of mango grown under the organic production system were observed for physical, chemical and sensory attributes. The varieties showed a percentage of pulp equal or above 60%, which makes them more suitable for processing. According to the PCA analysis, the characteristics soluble solids, total carotenoids, fruit mass, titratable acidity, h* and L* were considered the most important to differentiate the mango varieties evaluated. Ubá and Beta varieties had the highest levels of SS, while Favo de Mel was characterized by the highest values of TA and L*. The varieties Favo de Mel, Palmer, Surpresa, Juazeiro 2, Imperial and Joa had fruits with higher mass and h* values and the varieties Amrapali and Roxa Embrapa 141 had the highest levels of total carotenoids. Imperial, Palmer, Beta and Joa varieties were the most accepted for all sensory attributes.

ABSTRACT Pasta products are generally formulated based on wheat flour, and the insertion of other vegetable raw materials, such as pequi fruit, can provide increased nutritional value, along with differentiated technological and sensory characteristics. Thus, the aim of this study was to produce pasta with different levels of substitution of wheat flour with pequi pulp flour, to determine its proximate composition and to evaluate its technological and sensory properties. Pastas were produced with 5%, 10% and 15% of wheat flour being substituted by pequi pulp flour, and there was also a control group. Technological analyses (cooking time, volume expansion, water absorption, cooking loss, color difference and chromaticity), chemical analyses (moisture, ash, lipids, proteins and total carbohydrates) and sensory tests (acceptance and intention consumption) were carried out. The main results showed that pequi flour promoted an expansion in volume and water absorption in the product; raw and cooked pasta had more intense colors; moisture, ash and lipid content was increased by using pequi flour; and the sensory test scores for the samples with pequi were high in relation to the control samples, with the formulations with the highest content of pequi flour being the best evaluated. It is concluded that the pastas with pequi flour are promising products for the food industry.

ABSTRACT Morpho-agronomic characterization studies aiming at the discrimination and classification of lima bean accessions in relation to the centers of domestication and biological status have been of great importance for conserving the biodiversity of this species. For this purpose, researchers have widely used the multivariate analysis called discriminant analysis, which is not always capable of producing satisfactory results. Computational intelligence-based classifiers are additional tools for understanding complex classification problems. In this study, the objective was to test the use of the decision tree in the classification of lima bean according to the centers of domestication and biological status (cultivated and wild), based on eight phenotypic traits of the seed. Sixty accessions of lima bean from the Phaseolus Germplasm Bank of Universidade Federal do Piauí (BGP / UFPI) were evaluated, and classification was performed using two approaches: conventional statistics with discriminant analysis of principal components (DAPC) and computational intelligence through decision tree (DT). The results showed that the use of DT was efficient to identify patterns in the classification of lima bean accessions, due to its comprehensibility. Seed weight was one of the main descriptors used to explain the origin and diversity of the species. The results found will be useful for studies that involve the conservation of genetic resources, mainly for the maintenance of germplasm banks and in breeding programs. In addition, it is recommended to integrate machine learning algorithms in studies aimed at classifying lima bean.

ABSTRACT Little is known about the management of high-yield clonal Coffea canephora in the Amazonian Region, mainly for nutritional aspects and cultivation system efficiency. This study aimed to evaluate the influence of different nitrogen and potassium fertilization rates on coffee grain yield and fertilizer use efficiency of C. canephora trees. An experiment was performed at an experimental field of the Embrapa Rondônia in Porto Velho (RO), Brazil. It was carried out in a split-plot scheme with six doses of 20-00-20 NPK formulation (0; 250; 500; 1,000; 2,000; and 3,000 kg ha-1) and three years of evaluation (2014, 2015, and 2016). An interaction between fertilizer dose and crop year was observed. Fertilizer doses showed an exponential behavior, with maximum yields of 51, 114, and 79 bags ha-1 at 3,000 kg ha-1 in the crop years of 2014, 2015, and 2016, respectively. Such a behavior impacted average and accumulated yields in the three harvest seasons. As for crop year effect within each fertilizer dose, the highest yield was reached in the second harvest after pruning for renewal of orthotropic stems. Moreover, fertilizer use efficiency by plants decreased exponentially, with the highest value at the lowest dose. Increasing doses of 20-00-20 formulation promoted an exponential increase in grain yield but decreased its use efficiency by C. canephora plants. This management also stimulated a strong biannual production.

ABSTRACT Peppers and bell peppers (Capsicum spp.) are vegetables that have wide genetic variability, as well as a wide range of applications. Studies on genetic diversity help to understand the existing variability and the conservation of genetic resources, allowing breeders to select superior genotypes that meet the needs of breeding programmes. This study aimed to evaluate the genetic diversity among 15 Capsicum genotypes based on morpho-agronomic descriptors and through the Ward-MLM (Modified Location Model) procedure, as well as to indicate the most promising genotypes for breeding programmes. The research was conducted in an experimental area using a randomized block design, with three replications, using nine qualitative descriptors and ten quantitative descriptors. Analysis of variance was performed, and means were subsequently grouped by Scott-Knott’s method. There was a significant difference between genotypes for all traits evaluated, making it possible to select promising genotypes. According to the Scott-Knott grouping test, the number of seeds per fruit had the largest number of groups, with eight distinct groups, while plant height had only two groups. The genotypes GEN18 and GEN21 had the highest average values for fruit wall thickness and thus are indicated for the preparation of sauces. The genotypes GEN14 and GEN16 were the most promising for use for ornamental purposes. The Ward-MLM method made it possible to differentiate C. annuum L., C. baccatum L., C. chinense Jacq., and C. frutescens L. into different groups, and is thus a useful tool to detect genetic divergence.

ABSTRACT Peppers belong to the family Solanaceae and can be used for several different purposes. The use of morphological descriptors associated with multivariate techniques allows identifying pepper progenies that can be recommended for ornamental purposes. This study aimed to select segregating Capsicum annum progenies based on multivariate analyses. The study was conducted in a plant nursery at the Biotechnology and Plant Breeding Sector of the Center of Agricultural Sciences of the Federal University of Paraíba (CCA/UFPB). Twenty F3 progenies of ornamental peppers were used, namely: UFPB 5, 8, 10, 15, 18, 22, 25, 32, 33, 36, 40, 42, 49, 56, 60, 62, 64, 69, 75, and 77, plus four additional controls consisting of the parents UFPB 77.3 and UFPB137 and two commercial cultivars, Etna and Pirâmide. Seventeen plant and fruit traits were evaluated. The experimental design was completely randomized. The data were subjected to a multivariate analysis of variance. All analyses were performed with the software R, version 3.0.3. The results of the multivariate analysis of variance highlighted significant differences between the populations of ornamental peppers. Singh’s (1981) method made it possible to determine that eleven of the seventeen traits studied contributed with 73.7% of the genetic divergence, whereas six traits contributed with only 21.2%. There is genetic diversity among the evaluated progenies. Progenies 5, 10, 22, 33, 49, and 69 are recommended for selection for having ornamental traits for in-pot cultivation. Selection within these progenies is recommended to continue the breeding program of ornamental peppers for in-pot cultivation.

ABSTRACT Biomass produced in agricultural areas stores energy that can be used, contributing to regional development. Among the widely cultivated agricultural species is oats, destined for the production of not only grains and forage, but also biomass. The objective of this study was to characterize oat biomass in terms of the potential for energy generation considering the genetic and cultivation environment variability. Four field experiments were conducted in the state of Paraná and one in the state of São Paulo, Brazil, with black oat (Avena strigosa) and white oat (Avena sativa) cultivars. At the milky grain stage, plants were collected to quantify the production of shoot biomass and its qualitative variables for energy production and energy potential. Biomass yield varied between cultivars and cultivation sites. The mean higher calorific value was 17.9 MJ Kg-1, varying more between cultivation sites than between cultivars, being inversely proportional to the ash content. The contents of carbon, fixed carbon, volatile materials and nitrogen in the biomass did not vary between oat cultivars. The power generation potential varied widely between cultivars and cultivation sites, from 1557 to 3091 KWh ha-1, influenced mainly by the biomass yield, which overlaps the effects of the variations found in biomass quality. We concluded that oats are a species with high potential for use as an energy product, and the selection of the most productive cultivars regionally is crucial.