Everton Vinicius Zambiazzi

Agronomic performance of soybean according to stages of development and levels of defoliation

®according to the stages of reproductive development of the plant at defoliation and the levels of defoliation. A randomized block experimental design was used in a 6 × 3 + 1 factorial arrangement, composed of six reproductive stages at the time of defoliation [R1 (Beginning flowering), R2 (Full flowering), R3 (Beginning pod formation), R4 (Full pod formation), R5 (Beginning seed filling), R6 (Full seed filling -100% pod filling), and three levels of defoliation (33, 66 and 99%), as well as one additional treatment without defoliation, with three replications. The following features were evaluated: Plant height, number of pods per plant, number of grains per pod, harvest index, thousand seed weight, and grain yield. It was observed that all the levels of defoliation had a significant effect on the other variables studied, with the exception of plant height. The phenological stages at the time of defoliation had a significant effect on plant height, number of pods per plant, harvest index, and grain yield. There was a decline in grain yield with levels of defoliation as of 66%, and this decline was more significant with defoliation at the more advanced stages of the crop reproductive cycle.

Physiological and sanitary quality of soybean seeds harvested at different periods and submitted to storage1

ABSTRACT RESUMO and harvesting is naturally a crucial one. Soybean seeds reach their maximum dry mass accumulation and maximum physiological quality at the R 7 stage (beginning maturity) (Fehr et al. 1971), time when harvesting should be performed. However, because of the high moisture content of the seeds at that stage, harvesting is performed at the R 8 stage, when 95 % of the pods are mature in color (Diniz et al. 2013a).In many cases, the ideal harvesting time is exceeded due to the vast extension of planted areas and insufficient harvesters, or due to high rainfall rates during the harvesting process. Therefore, seeds may remain exposed in the field for longer periods.Soybean seeds, when stored in the field, are subject to adverse conditions such as climatic 1. Manuscript received in Jun./2017 and accepted for publication in Sep./2017 (http://dx.doi.org/10.1590/1983-40632016v4747576).2. Universidade Estadual do Mato Grosso do Sul, Cassilândia, MS, Brasil. E-mails : alan_zuffo@hotmail.com, steiner@uems.br.3. Universidade do Estado de Mato Grosso, Nova Xavantina, MT, Brasil.

Seed quality response of Urochloa humidicola cv. Llanero to drying surfaces and environments1

1. Manuscript received in Feb./2018 and accepted for publication in Sep./2018 (http://dx.doi.org/10.1590/1983-40632018v4851396). 2. Universidade Federal de Mato Grosso do Sul, Departamento de Agronomia, Chapadão do Sul, MS, Brasil. E-mail/ORCID: alan_zuffo@hotmail.com/0000-0001-9704-5325. 3. Universidade do Estado de Mato Grosso, Departamento de Agronomia, Nova Xavantina, MT, Brasil. E-mail/ORCID: zuffojr@gmail.com/0000-0001-7671-2096. 4. Universidade Federal de Lavras, Departamento de Agricultura, Lavras, MG, Brasil. E-mail/ORCID: everton_zambiazzi@hotmail.com/0000-0002-4598-9129. 5. Universidade Estadual de Mato Grosso do Sul, Departamento de Agronomia, Cassilândia, MS, Brasil. E-mail/ORCID: steiner@uems.br/0000-0001-9091-1737. The drying process and storage may interfere in the quality of creeping signalgrass seeds [Urochloa humidicola (Rendle.) Morrone & Zuloago, syn. Brachiaria humidicola (Rendle.) Schweick.]. This study aimed to evaluate the physical, physiological and sanitary quality of creeping signalgrass cv. Llanero seeds submitted to drying surfaces and environments and stored for two periods (1 and 8 months). The experiment was arranged in a completely randomized design, in a 4 × 2 × 2 + 2 factorial arrangement, with four drying surfaces (soil, asphalt, concrete and ceramic floor), two drying environments (seeds exposed to the sun or shade), two seed storage periods (1 and 8 months) and two additional treatments with drying in paper bags under laboratory conditions (control) and stored for 1 or 8 months, with four replicates. The water content, viability by the tetrazolium test, electrical conductivity, germination rate, germination rate index and seed sanitary quality were measured. Drying at full sun impaired the physiological quality of the seeds due to the high temperatures (46.8-51.0 oC) of the drying surface; however, reduced the incidence of pathogens. The drying of seeds in paper bags under shade results in a higher physiological quality, but the sanitary quality is compromised. However, the pathogens present in the seeds did not inhibit their viability and vigor. The storage for eight months reduces the seed quality.

Development of Plants in Combination of Products Associated with the Inoculation in the Soybeans Seeds Treatment

The purpose of this study was to evaluate the effect of different combinations of products applied through seed treatment, associated with the inoculation, in the development of soybean plants. The experiment was conducted in a greenhouse at Federal University of Lavras (UFLA). The experimental design was a randomized complete block, with four repetitions in a factorial 4 × 11, being four soybean cultivars and 11 combinations of products associated with the inoculation in the treatment of seeds. At the stage (R 1 ) it was evaluated: plant height, leaf area, foliar chlorophyll content, number of trifoliate leaves, dry shoot mass, dry root mass, root length, root volume, nodules total number, viable nodules total number, nodules dry mass and foliar nitrogen content. The combination of products in the treatment of seeds, do not present phytotoxic effects in the characters related to the development, except for dry matter of aerial part and root volume. The combination of products in treatment of seeds influences negatively the nodulation, especially in the treatments with presence of nematicide. The inoculation performed in isolation or combined with fungicide and insecticide (I+FI) maintains nodule levels.