ABSTRACT Fusarium wilt, caused by soil-borne Fusarium oxysporum f. sp. tracheiphilum (Fot), can reduce cowpea bean yield. Considering that genetic control through resistant genotypes is pivotal for Fusarium wilt control, the aim of the present study was to identify cowpea genotypes that are resistant to Fot from the Germplasm Bank of the Pernambuco Agronomic Institute, Embrapa Middle North, and other producing areas in the North and Northeast regions of Brazil. The cultivar BR-17 Gurguéia was used as a susceptible control and MNC01-649F-2-1 was used as a resistant control. Two experiments were carried out in a completely randomized design in the greenhouse of the Department of Agronomy of the University Federal Rural of Pernambuco. Plants with the first pair of expanded leaves were inoculated with a conidial suspension (106 conidia/mL) using the conidia root-immersion methodology. Fusarium wilt severity in plants was assessed 21 d after inoculation, with the aid of a descriptive scale. In the first experiment, we evaluated the resistance of 38 cowpea genotypes, of which 19 (5 moderately resistant and 14 resistant) were selected for the second experiment. In the first experiment, four genotypes (Canapu PE, Miranda IPA 207, Esperança, and BRS Pujante) did not show any symptoms of Fusarium wilt. In the second, 15 genotypes showed high resistance to Fot, including Canapu PE and Miranda IPA 207, which again had no symptoms of Fusarium wilt. In conclusion, this study identified that the genotypes, Canapu PE, Miranda IPA 207, Esperança, and BRS Pujante have greater resistance to Fusarium wilt.

ABSTRACT Previous investigations showed that diverse varieties of melon may have different attractiveness for bees. Therefore, the objective of this study was to evaluate the composition, frequency and behavior of flower visitors of some melon (Cucumis melo) cultivars (Amarelo, Pele de Sapo, Cantaloupe, Gália) in different conditions (conventional and organic farming, dry and rainy seasons, with and without mulching and introduction or not of honey bee hives) in the main production poles in the Brazilian Northeast (Petrolina-PE/Juazeiro-BA, Pacajus-CE and Mossoro-RN). Observations and collections of flower visitors occurred from 5p.m. to 6p.m, in non-consecutive days. We recorded 12 species of insects, mostly bees. The most frequent was Apis mellifera (99.68%), but other species appeared sporadically (less than 0.5%): Xylocopa grisescens, Trigona spinipes, Plebeia sp., Melipona mandacaia, Frieseomelitta doedereleini, Halicitidae. Apis mellifera was present in all studied cultivars and sites. Xylocopa grisescens appeared in two poles, but not in Pacajus-CE, Amarelo cultivar. In addition, Trigona spinipes, although present in the three poles, was not recorded on Pele de Sapo. The Amarelo cultivar, under organic farming, without the use of mulching, and presence of honey bee hives, in the Petrolina-PE/Juazeiro-BA pole, in the dry season, was the combination of factors showing the largest number of Apis mellifera as the main visitor of melon flowers.

ABSTRACT This study aimed to compare three methods of estimating the optimum plot size to evaluate the fresh matter productivity of pearl millet (Pennisetum glaucum L.), slender leaf rattlebox (Crotalaria ochroleuca), and showy rattlebox (Crotalaria spectabilis). Twenty-seven uniformity trials were carried out with pearl millet, slender leaf rattlebox, and showy rattlebox cultivated alone and intercropped. Fresh matter productivity was evaluated in 972 basic experimental units (BEU) of 1 m × 1 m (36 BEU per trial). The optimum plot size was determined using the methods modified maximum curvature, linear response with plateau model, and quadratic response with plateau model. The optimum plot size differs between methods and decreases in the following order: quadratic response with plateau model (9.94 m2), linear response with plateau model (7.41 m2), and modified maximum curvature (3.49 m2). The optimum plot size to evaluate the fresh matter productivity of pearl millet, slender leaf rattlebox, and showy rattlebox cultivated alone or intercropped is 7.41 m2. This size could be used as a reference for future experiments.

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 Cenostigma pyramidale, a pioneer species presents in all different successional stage (early, intermediate and late) of fifteen natural regeneration areas of Caatinga after land used changed and abandonment was used to investigates the morphological and physiological attributes that are very important to xeromorphic conditions as against herbivories. Leaf samples were collected to evaluate the percentage of the herbivory and index of sclerophylly. Anatomy, histochemistry, total phenolic content, epicuticular wax load, and n-alkanes profile were also performed. The results showed an inverse relationship between the percentage of herbivory and the index of sclerophylly. The leaves showed typical morphological and anatomical characteristics of xeric environments plants such as uniseriate epidermis and trichomes. Furthermore, it was also noticed a decrease in the overall thickness and the tissues according to the advancement of the successional stages. The histochemical revealed the presence of lipidic substances coating the epidermal layers, phenolics compounds stored in secretory structures, and starch in the mesophyll. The concentration of phenolics compounds indicating the difference from health leaves of plants between different stages of regeneration, but no difference when they were herbivored. The amount of cuticle wax did not change significantly with the successional stage. The profile of n-alkanes was characterized by the predominance of nonacosane (C29) and hentriacontane (C31). The C29 content decreases with the advancement of the successional stage, while the C31 content increases. All those attributes have a role to protect the plants to acclimate to the various environmental conditions of Caatinga.

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 The intense anthropization in the lower São Francisco River and surrounding areas can lead to environmental degradation risks and, above all, makes the area more susceptible to soil erosion. This study aimed to identify and correlate the physical and chemical properties able to enhance erosive processes and slope instability in the watercourse margins of the lower São Francisco River, in Sergipe State, Brazil. To this end, disturbed and undisturbed samples of an Entisol-Fluvent soil were collected in the region, specifically in the city of Amparo de São Francisco. Physical (density, porosity, and texture) and chemical (pH, cation exchange capacity, base saturation, micro-, and macronutrients) analyses were performed. All physical properties and organic carbon contents were higher in the surface layers (Ap and AC) compared to the others. Organic carbon, phosphorus, and micronutrients had a negative correlation with soil density, showing higher contents and lower soil densities in the Ap and AC layers. The pedological characteristics of the evaluated soil layers are unable to provide soil resistance to water erosion.

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.