-The objective of this work was to evaluate the agronomic performance of elite-strains of cowpea cultivars under the conditions of the north of Minas Gerais (MG), Brazil. Fifteen elite-strains and five erect and semi-erect cultivars of cowpea were evaluated in the 2014 and 2015 summer-fall crop seasons in Janaúba MG. A randomized block experimental design was used with four replications. Plant size, lodging and value of cultivation, pod length and grain yield were evaluated. The data of the two crops were subjected to individual and joint analysis of variance. The genotype-crop interactions significantly affected all studied variables. The strains MNC04-792F-146 and MNC04-792F-144 stood out as the most productive genotypes in both crops. The cultivars BRS Itaim and BRS Novaera presented adequate size and lodging characteristics for cultivation, and values of cultivation that meet commercial standards, thus representing good alternatives for the genotypes cultivated in the north of Minas Gerais.Keywords: Vigna unguiculata. Value of cultivation. Yield. PERFORMANCE AGRONÔMICA DE GENÓTIPOS DE FEIJÃO-CAUPI ERETOS E SEMIERETOS NO NORTE DE MINAS GERAIS

The use of cover crops is a strategy to maintain the productive capacity of agricultural soils. The increase of organic carbon content, nutrient cycling and, consequently, the increase in soil fertility are some of the greatest benefits. This study evaluated the chemical attributes of the soil after the use of cover crops species in the Cerrado region of Piaui. The experiment was carried out from January 2015 to July 2016. It was performed in a completely randomized block design with eleven treatments and four replicates. ), potential acidity (H + Al), soil organic carbon (OC), the saturation of bases (V%), saturation by aluminum (m%) and effective CEC were measured. Fifteen months after their establishment, cover crops positively influenced the levels of P, K and OC with no changes in the other chemical properties. The OC contents were higher with the use of C. cajan -cv. 'fava larga', brachiaria and C. ochroleuca + millet, mainly in the topsoil. C. espectabilis, spontaneous vegetation, M. aterrima, brachiaria and C. ochroleuca were the most efficient in K cycling.

The objective of this work was to evaluate the effect of the industrial treatment with insecticides on the physiological quality of corn (Zea mays) seeds during storage at different temperatures. Seeds of the BM 950 PRO3 and BM 709 PRO2 hybrids were subjected to industrial treatment with insecticides based on chlorantraniliprole, cyantraniliprole, and clothianidin, as well as to a control, and stored at different temperatures (10, 20, and 30°C) for 0, 90, 180, 270, and 360 days, in a 4x3x5 factorial arrangement for each hybrid, in a completely randomized design. To evaluate the quality of the seeds, tests of moisture content, germination, seedling emergence, accelerated aging, and cold were performed. For the seeds of both hybrids, germination is preserved at minimum commercialization standards for up to 360 days of storage, regardless of the insecticide or storage temperature. The temperature of 10°C preserves seed vigor and minimizes the negative effects caused by the insecticides during storage. At 20 and 30°C, vigor is cumulatively impaired as storage is extended, mainly at 30°C. Chlorantraniliprole results in a greater preservation of seed vigor regardless of storage temperature, whereas clothianidin provides a greater loss of vigor in industrially treated corn seeds, especially when stored at 30°C.

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Seed treatment is important for protecting seed and seedling from pests and/or pathogens. Seed treatment can be performed generally in two ways: industrial seed treatment (IST), performed by seed companies, or on-farm treatment (OFT). These treatment technologies will affect the final quality of the process. Therefore, the objective of this study was to characterize the seed quality profile of ISTs and OFTs in Brazilian agribusiness in terms of functional quality and dose application effectiveness (DAE). Seed samples treated by both processes were collected in 6 producing states of Brazil, Mato Grosso, Goiás, Paraná, Minas Gerais, São Paulo, and Santa Catarina. To evaluate the functional quality of the treatments, the coating percentage was determined by high-resolution image analysis with GroundEye® equipment, and the insecticide active ingredient DAE amount was determined with high-performance liquid chromatography (HPLC). Image analysis proved to be a promising technique to evaluate seed coating, in addition, samples treated with “on farm” technology had greater variation and heterogeneity in coating and active ingredient dose, while samples treated industrially showed greater homogeneity, uniformity, effectiveness of applied products. There was a strong positive correlation between coating with phytosanitary products and DAE in treated corn seeds, important parameters in the evaluation of the quality of the treatment.