ABSTRACT The use of filler liming in the sowing furrow can improve the chemical characteristics of the soil and, together with nitrogen fertilization, increase common bean yield. The objective of this study was to determine the effect of filler liming of the sowing furrow along with nitrogen topdressing fertilization on the yield of common bean, cultivar Pérola, irrigated by central pivot, in the Cerrado Region. The field experiments were conducted for three consecutive cropping years, in a randomized block design with four replications, in a 2x4 factorial scheme, consisting of two doses of nitrogen topdressing fertilization (zero and 60 kg ha-1 of N) and four doses of filler liming application in the sowing furrow (0, 200, 400 and 600 kg ha-1 of CaCO3). The plant density (PD), number of pods (NP), number of grains (NG), mass of 100 grains (M100) and, grain yield (GY) were evaluated. The use of 60 kg ha-1 of N provided greater M100 and GY. The increase of the filler liming doses in the sowing furrow led to a reduction of the NP. The filler liming dose of 200 kg ha-1 provided higher values of NG and M100, and when combined with the nitrogen topdressing fertilization, improved the GY of the common bean.

ABSTRACT The aim of the present study was to determine the beekeeping potential of Croton heliotropiifolius Kunth (Euphorbiaceae) based on flowering strategy, floral characteristics, available floral resources, and the individuals frequencies and foraging activities of Apis mellifera L. on its flowers in Fazenda Ingazeira, Brazil. Each C. heliotropiifolius plant possessed inconspicuous diclinous flowers clustered into 560 ± 60 dense terminal inflorescences containing 59 ± 12 pistillate and 160 ± 26 staminate flowers. Although both types of flowers produced nectar (pistillate: 2.8 ± 0.8 μL ; staminate: 0.3 ± 0.06 μL ), A. mellifera workers mostly visited staminate flowers (98%) during the peak visitation period (08:00-11:00 h). Moreover, during the foraging period, each plant produced approximately 5.376 × 10 8 pollen grains, ensuring approximately 33 visitation cycles from a colony of A mellifera workers that picked up an average of 405 pollen grains per visit per flower. Further, C. heliotropiifolius showed an annual cornucopia flowering strategy with high flower production for five months, which is an important characteristic that ensures floral resource availability in the environment. These findings suggest that C. heliotropiifolius has a great potential for apiculture in this region.

ABSTRACT This study was carried out with the objective of evaluating the water relations, photosynthetic pigments and growth of passion fruit cv. BRS Rubi do Cerrado, as a function of the cationic nature of irrigation water and exogenous application of hydrogen peroxide. The experiment was carried out under greenhouse conditions in Pombal – PB, Brazil. The experimental design was randomized blocks, in a 6 × 4 factorial scheme, corresponding to six cationic nature of water - CNW (S1 - Control; S2 - Na+; S3 - Ca2+; S4 - Na++Ca2+; S5 - Mg2+ and S6 - Na++Ca2++Mg2+) and four concentrations of hydrogen peroxide - H2O2 (0, 20, 40 and 60 μM), distributed in a randomized block design with four replicates. Plants in the control treatment (S1) were irrigated using water with electrical conductivity (ECw) of 0.3 dS m-1, while those of the other treatments (S2; S3; S4; S5 and S6) were subjected to ECw of 3.0 dS m-1, prepared with different cation(s). Application of 60 μM of H2O2 reduced the percentage of intercellular electrolyte leakage in plants irrigated with water of calcic composition. Salinity of water composed of sodium, sodium+calcium and sodium+calcium+magnesium, and H2O2 concentrations of 40 and 60 μM resulted in lower leaf water potential. The biomass accumulation of passion fruit was more sensitive to the variation of the electrical conductivity of the water. Regardless of the cationic nature, the use of water with electrical conductivity of 3.0 dS m-1 produced passion fruit seedlings with a Dickson quality index higher than 0.2, considered acceptable.

ABSTRACT Corn, one of the main grain crops in Brazil, needs to have its nutritional requirements fully satisfied to achieve high biological productivity. Thus, the objective of this work was to evaluate the influence of increasing doses of poultry litter biochar on nutrient concentrations in the leaves of hybrid corn BRS 2022 and in the soil after harvest. The experiment was carried out in a completely randomized design, with four replicates, evaluating six doses of biochar (0; 2.02; 4.05; 6.07; 8.10 and 10.12 t ha-1) and the plots composed of one plant per pot with a volume of 20 dm3. The collection of leaves for leaf diagnosis was carried out at the time of flowering, removing the opposite leaf from the ear base in the middle third region. These leaves were dried in a forced air circulation oven, 65 °C, for a period of 48 hours, ground, sieved through 20 mesh and analyzed for the concentrations of macronutrients in the leaf tissue. At the end of the experiment, 83 days after corn sowing, soil samples were collected as a function of the treatments and then analyzed chemically. Biochar application promoted an increase in the leaf contents of N, P and K, resulting in improvements in the nutritional status of plants for these nutrients. The chemical characteristics of the soil, analyzed after the corn harvest, revealed that there was an influence of the doses of biochar on the levels of calcium, organic carbon, potassium and phosphorus.

ABSTRACT Yellow passion fruit is a fruit species widely cultivated throughout the Brazilian semi-arid territory, but its yield is affected by the quality of the waters of this region. In this context, the objective was to evaluate the gas exchange and production of passion fruit cv. BRS Rubi do Cerrado irrigated with waters of different cationic natures. The study was conducted in drainage lysimeters under greenhouse conditions in Campina Grande, PB, Brazil, in a randomized block design, and the treatments were eight cationic natures of irrigation water (S1 - Control; S2 - Na+; S3 - Ca2+; S4 - Mg2+; S5 - Na+ + Ca2+; S6 - Na+ + Mg2+; S7 - Ca2+ + Mg2+ and S8 - Na+ + Ca2+ + Mg2+) with three replicates. Plants in the control treatment were irrigated with water of low electrical conductivity (ECw = 0.4 dS m-1), while those of the other treatments were irrigated using water with ECw of 3.5 dS m-1. The treatments Na+ + Ca2+, Na+ + Mg2+ and Ca2+ + Mg2+ were prepared in the equivalent ratio of 1:1, and Na++Ca2++Mg2+ in the ratio 7:2:1, respectively. Water salinity of 3.5 dS m-1 reduced gas exchange, and stomatal conductance and transpiration were the most sensitive variables of passion fruit. The number of fruits of passion fruit cv. BRS Rubi do Cerrado decreased with water salinity, regardless of the cationic nature. The waters of calcic and calcic+magnesian nature caused the greatest deleterious effects on the production variables of passion fruit, at 259 days after transplanting.

ABSTRACT The objective of this work was to characterize the physical and physicochemical parameters of pequi powders obtained by means of convective drying at different temperatures (50, 60, 70 and 80 °C) and pulp layer thicknesses (0.5, 1.0 and 1.5 cm). Initially, the physicochemical characterization of fresh pulp was carried out, followed by convective drying under the conditions mentioned, until the equilibrium moisture content and subsequent disintegration to obtain the powders. Subsequently, the physical and physicochemical properties of the obtained powders were analyzed and the best powder was selected based on reduced moisture content and water activity and lower peroxide index. Pequi pulp showed a high fat content and a yellowish color; with the increase in drying temperature, there were reductions in the moisture content, water activity and protein content of the powders. As for the color parameters, the powder showed a darkening with the increase in drying time; the water adsorption isotherms of the selected pequi powder were classified as Type II, and the GAB model showed the best fits. The pequi powders showed good solubility and low cohesiveness. The powder that showed good flowability was produced at a drying temperature of 60 °C and with pequi pulp layer thickness of 0.5 cm.

ABSTRACT The quality parameters of cassava roots vary between cultivars and depend on abiotic factors, such as plant nutrition. However, the magnitude of how these factors interfere is not yet well defined, especially for phosphorus (P), which is a nutrient directly linked to the synthesis of sugars and starches in plants. Thus, the objective of the research was to evaluate the quality of roots of table cassava cultivars fertilized with doses of P in the Brazilian semiarid. The research was carried out at the Rafael Fernandes experimental farm, Mossoró, RN, Brazil, from June 2018 to April 2019. The experimental design used was in randomized blocks, arranged in subdivided plots and with four replications. Doses of P (0, 60, 120, 180 and 240 kg ha-1 of P2O5) were applied in the plots, and in the subplots, the table cassava cultivars (Água Morna, BRS Gema de Ovo, Recife and Venâncio). Firmness, elasticity, titratable acidity, soluble solids, total soluble sugars, starch and cooking were all evaluated. The quality of table cassava roots varied depending on the cultivar and the dose of P. Doses of P between 120 and 240 kg ha-1 of P2O5 increase the starch content and reduce the cooking time of table cassava roots.

ABSTRACT Green manuring is an important management strategy in tuberous vegetable production systems, since it improves the physical, chemical and biological properties of the soil and, consequently, increases in crop productivity and ecosystem balance. The objective of this work was to evaluate the agro-economic efficiency of carrot cultivation as a function of Calotropis procera biomass amounts incorporated into the soil during two growing seasons in a semiarid environment. The experiments were conducted in an experimental design of randomized complete blocks, with four treatments and five replications. The treatments consisted of four C. procera biomass amounts (20, 35, 50 and 65 t ha-1) incorporated into the soil. In each experiment, one plot with carrot without fertilization (control) was planted, for the purpose of comparison. The characteristics evaluated in the carrot were productivities of total and commercial roots, classified productivity of roots and production economic indicators. The maximum productivity of carrot roots of 35.90 t ha-1 was possible with the incorporation of 47.60 t ha-1 of C. procera biomass into the soil. The maximum net income of R$ 33.744,07 ha-1 in the cultivation of this vegetable it was achieved with the addition of the C. procera biomass amount to the soil of 42.81 t ha-1. The return rates obtained for the carrot cultivation in these optimized quantities were 1.53 and 1.28, respectively, of those achieved in the control treatment (without fertilization).

ABSTRACT The common bean exhibits wide genetic variability for technological quality traits, mineral concentrations, and bioactive compounds. For this reason, investigating the correlations between those traits in common bean lines of different gene pools contributes to the progress of biofortification programs. In the present study, two recombinant inbred line populations of Mesoamerican and Andean common bean were evaluated at the F5:7 generation. Technological quality was evaluated based on mass of 100 grains and seed coat color, which was determined using a colorimeter that analyzed the L* (white to black), a* (green to red) and b* (blue to yellow) values. The concentration of six minerals and bioactive compounds (phytates and phenolic compounds) was evaluated and used to characterize the nutritional composition of the lines. The evaluated common bean lines differed (p ≤ 0.05) for all technological quality traits, mineral concentrations, and bioactive compounds, except for the zinc concentration in Andean beans. Seed coat color (L*, a*, and b* values) was highly correlated with most of the evaluated minerals and with the phytates in Mesoamerican beans. In Andean beans, seed coat color (L*, a*, and b* values) was correlated with the concentrations of potassium, magnesium, iron, and phenolic compounds. The nutritional composition of common bean lines of different classes is variable: black beans have higher concentrations of potassium, phosphorus, calcium, zinc, and phytates; carioca beans stand out with high magnesium concentration; and cranberry beans have higher concentrations of potassium, magnesium, and iron.

ABSTRACT The objectives of the tests were to evaluate concentrations of indolebutyric acid (IBA) combined with different types of cuttings and grafting methods on the vegetative propagation of cajazeira-dejabuti (S. testudinis). The experiment with stem cuttings was conducted in a greenhouse with an intermittent misting system. The experimental design was completely randomized in a 5 x 6 factorial arrangement consisting of five cutting types: apical, medial, basal, stratified, and tanchan, and six IBA concentrations: 0, 1,000, 2,000, 3,000, 4,000, and 5,000 mg kg-1, with four replications of ten cuttings. The experiment with the root cuttings followed a randomized block design composed of six IBA concentrations (0, 1,000, 2,000, 3,000, 4,000, and 5,000 mg kg-1) with four replications, evaluating after 120 days the percentages of live, sprouted, rooted, and calloused cuttings, and the number and dry mass of roots and sprouts. Five grafting methods (chip budding, shield budding, cleft grafting, wedge grafting, and splice grafting) were tested by evaluating the graft success and sprouting percentages at 30 and 60 days after grafting, respectively. Statistical analyses were performed using the Kruskal-Wallis non-parametric test. The IBA concentrations of 0, 2,000, 3,000, and 5,000 mg kg-1 increased the number of sprouts in tanchan cuttings. The tanchan cuttings showed the highest survival and percentage of sprouts regardless of the IBA concentration. The IBA concentration of 2,200 mg kg-1 promotes higher rooting rates in root cuttings. Splice grafting provides higher graft success and sprouting rates.