The umbuzeiro is a native Brazilian semi-arid plant with great agroindustrial potential. The characterization of the fruit, as well as the development or improvement of technologies for value aggregation are fundamental for its conservation, dissemination and culinary expansion. The objective was to characterize physically and chemically fruits of umbu and to define the access with greater commercial potential. A completely randomized design was used, with 10 replications, in a total of 4 accessions of umbuzeiro. The fruits were selected prioritizing uniformity of fruit size and maturation stage. Fruit peel color was analyzed; diameter and length; mass of the fruit, the bark, the pulp and the seed; firmness of the fruit, soluble solids contents; pH; titratable acidity and solids/acidity ratio. The values of the pulp yield and the technological index were determined. Significance was verified for all variables, except for soluble solids and pH. The average value of the titratable acidity was 1.3 mg of citric acid 100 mL-1 of juice. The diameter of the fruits varied between 4.0 and 4.5 cm. Fruit mass varied from 33.00 to 43.62 g and access to EPAMIG-C06 was the heaviest. The accesses EPAMIG-C06 and EPAMIG-C18 presented the highest technological index. Based on the results, it was concluded that the accesses present potential to the pulp industry due to the size and characteristics of the fruits. The umbu accesses under study presented small variation for solubility and pH. For in natura consumption and/or processing, the access EPAMIG-C06 stands out due to attributes of commercial interest.

The continuous use of KCl may not be sustainable in the long term in agricultural systems. High doses used in crops accumulate in the soil and plants, hindering the metabolic processes of soil organisms. This study assessed the soil microbial activity in response to the application of K sources in banana crop and effects on microbial C. The experimental design was completely randomized with four K sources: potassium nitrate (KNO3), potassium chloride (KCl), potassium sulfate (K2SO4), and monopotassium phosphate (KH2PO4) at 200 mg kg-1 of K2O, besides the control (without K) and combinations KCl:K2SO4. KCl application increased microbial activity 7 days after incubation, with gradual reduction over time. The isolated application of K2SO4 and the combination KCl: K2SO4 at the ratio 60: 40% increased total CO2 released by the microbiota. K2SO4 source had the highest microbial biomass C (MBC), as well as the 60: 40 combinations. Isolated application of K sources, especially with high chloride concentration, reduces the soil microbial activity and MBC.

As informações referentes às taxas de recuperação do boro pelo extrator em razão das doses adicionadas são escassas e necessárias para os sistemas de recomendação de adubação e corretivos. Esta pesquisa teve o objetivo de determinar as taxas de recuperação desse nutriente com água fervente e CaCl2 fervente em solos dos Estados da Bahia e Minas Gerais, na ausência e na presença de calagem. O experimento foi instalado em casa de vegetação, utilizando tratamentos em esquema fatorial (6 × 2 + 9) × 6, correspondendo a seis solos com e sem calagem, nove solos sem calagem e seis doses de B. Utilizaram-se blocos casualizados, com três repetições. As unidades experimentais foram constituídas por 0,6 dm3 de solo. A calagem foi calculada com base na análise de solo, seguindo a recomendação de calagem usada para o Estado de Minas Gerais. Após 15 dias de incubação, os solos receberam doses de B (0,0; 1,5; 3,0; 6,0; 9,0; e 15 mg dm-3), fazendo-se uma nova incubação por um período de 45 dias. Usou-se ácido bórico como fonte de B. Terminada a incubação, o teor de B disponível foi extraído com água fervente e CaCl2 5 mmol L-1 fervente, sendo a dosagem feita com azometina-H. Foram feitas análises de regressão e correlação para as diversas variáveis. O B extraído do solo com água fervente e o CaCl2 fervente, independentemente da calagem, aumentou linearmente com a elevação das doses aplicadas desse nutriente aos solos. Os extratores água fervente e o CaCl2fervente não são sensíveis à calagem. As taxas de recuperação de B dos solos pelos extratores usados variam de acordo com os teores de matéria orgânica, a quantidade e qualidade de argila e pelo equivalente de umidade. Os extratores utilizados foram altamente correlacionados entre si na extração do B do solo.

Leafy vegetables have a high demand for nitrogen availability; however, excessive nitrogen supply causes economic, environmental and agronomic losses, compromising food security. Given the above, the objective was to assess the agronomic responses of arugula that are associated with different nitrogen sources and doses. The experiment was run under greenhouse conditions. A randomized block design was employed; the blocks were arranged in a factorial scheme (2 × 4), using two sources (urea and calcium nitrate) and four nitrogen doses (0, 40, 120 and 360 mg kg-1), with four replications. Thirty-five days after transplanting, the following were assessed: plant height, number of leaves, shoot fresh mass, root fresh mass, shoot dry mass, root dry mass, shoot/root dry matter ratio, leaf area, and leaf nitrogen content. It was found that nitrogen fertilization optimizes crop development and yield. Doses of 100 to 272 kg ha-1 promote increase in plant height and leaf number, respectively. Under the conditions studied, 200 kg ha-1 of N is recommended as a dose of maximum economic efficiency in arugula production. Calcium nitrate is indicated as the best nitrogen source for the production of the crop.

The objective was to evaluate the production yield and influence of the action of ascorbic acid on the color of dehydrated white and purple sweet potatoes produced in a semi-arid region. The experiment was carried out at the Laboratory of Technology of Products of Plant Origin (TPOV) of the State University of Montes Claros, Janáuba, Minas Gerais, Brazil. Sweet potato roots of the cultivars Brazlândia roxa and Brazlândia branco were used. To determine the action of ascorbic acid on the color of dehydrated white and purple sweet potato, a completely randomized design with 4 replications was used. Analysis of variance was performed in a 2 × 2 factorial scheme, with two cultivars (Roxa and Branca) and absence and presence of ascorbic acid. The results were submitted to statistical analysis using the Sisvar Software. The average yield of white potato was 23% and purple 18.41%. For the variable of soluble solids, no significant differences were observed between the varieties. The sweet potato cultivar Brazlândia Branca showed better yield when submitted to the drying process. The sweet potato cultivar Brazlândia, when submitted to the dehydration process, presented a more yellowish color, however, with less intense coloration in the presence of ascorbic acid.