Claudinei Kappes

Desempenho de híbridos de milho em diferentes arranjos espaciais de plantas

Due to recenthy introduced maize genotypes, the reassessement of recommendations of management practices is necessary, among them, the spatial arrangement of plants. In this way, this study has as aim to evaluate the best plant arrangement for the corn hybrids XB 6010, XB 6012, XB 7253, XB 9003 and AG 9010 in spacings between rows of 0.45 and 0.90 m and at populations of 50,000, 60,000, 70,000, 80,000 and 90000 plants ha-1. The experiment was carried out on the crop year of 2009 in Selviria (MS), following a randomized block design with two spaces arranged in bands within each block and the 25 combinations hybrid x populations randomized within spacing. The results were submitted to F test, with the effects of hybrids and spacing compared by Tukey test (p<0.05) and populations by regression analysis. Independent of hybrid and population, the spacing influenced only the stalk diameter, and the use of 0.45 m between rows proportioned the production of plants with larger stalk diameter. Stalk diameter, ear length, ear diameter, prolificacy and weight of one hundred grains decreased linearly with increasing plant population, while plant height was not affected. The best arrangements were: AG 9010 with 90,000 plants ha-1 and spacing of 0.45 m; XB 7253 with 72,000 plants ha-1 in both row spacings; and as XB 6010, XB 6012 and XB 9003 did not respond to such arrangements, being recommended 50,000 plants ha-1 in the two spacings.

Qualidade fisiológica de sementes e crescimento de plântulas de feijoeiro, em função de aplicações de paraquat em pré-colheita

The physiological quality of seeds and the growth of bean seedlings are influenced by the production environment and handling practices, such as the pre-harvest chemical desiccation. This study aimed to evaluate the physiological quality of seeds and growth of bean seedlings, after pre-harvest paraquat applications in different times and rates. A randomized blocks design, in a 4x4 (application time x herbicide rates) factorial scheme, was used, with four replications. The paraquat was applied at 30, 35, 40, and 45 days after flowering (DAF), in rates of 0 g ha -1 , 200 g ha -1 , 400 g ha -1 , and 600 g ha -1 . The results were submitted to variance analysis, the times compared by using the Tukey test and the rates by regression. The germination, accelerated aging of seeds, and total seedling length were not affected after the pre-harvest paraquat applications. However, the germination, after the cold test, and the seedling shoot length were affected by paraquat application times, presenting better results when the desiccant was applied at 30 DAF. The electrical conductivity of seeds decreased linearly in proportion to the increase of paraquat rates, and similar results were also observed for primary root length of seedling, with application at 30 DAF, and for first germination counting and germination speed index, with application at 45 DAF. The physiological quality of seeds and growth of seedlings were affected by pre-harvest paraquat application.

Manejo do solo e do nitrogênio em milho cultivado em espaçamentos reduzido e tradicional

Praticas agronomicas que ajudem o agricultor a elevar a produtividade e a diminuir os custos de producao devem ser estudadas para garantir a sustentabilidade da agricultura. Assim, desenvolveu-se um experimento com o objetivo de estudar o efeito do manejo do solo, do nitrogenio e do espacamento entrelinhas na cultura do milho em dois anos agricolas. O experimento foi instalado sobre um Latossolo Vermelho Distrofico em delineamento experimental de blocos casualizados em esquema fatorial 3 x 5 x 2 com quatro repeticoes. Os tratamentos foram constituidos pela combinacao de tres manejos do solo (grade aradora + grade niveladora, escarificador + grade niveladora e plantio direto), cinco epocas de aplicacao do nitrogenio [testemunha sem N, 120 kg ha-1 na semeadura (S), 120 kg ha-1 no estadio fenologico V6, 30 kg ha-1 (S) + 90 kg ha-1 em V6, 30 kg ha-1 (S) + 45 kg ha-1 em V4 + 45 kg ha-1 em V8] e dois espacamentos entrelinhas (0,45 e 0,90 m) com populacao fixa. Concluiu-se que o sistema plantio direto promoveu maior populacao final de plantas e maior produtividade de graos; a aplicacao precoce de todo o N proporcionou produtividade de graos semelhante aos manejos com parcelamento, e o espacamento de 0,90 promoveu maior massa seca dasplantas quando o preparo foi feito com grade aradora + niveladora.

Produtividade de feijoeiro de inverno submetido à dessecação com paraquat na pré-colheita

Knowledge on time and rate of desiccant application in pre-harvest of common bean is important to prevent yield losses. The objective of this work was to evaluate the yield of the winter common bean after application of paraquat as desiccant at different times (30; 35; 40 and 45 days after the beginning of flowering - DAF) and rates (0; 200; 400 e 600 g ha-1) in pre-harvest. The experiment was conducted in the fall/winter growing season of 2010, in Selviria, Mato Grosso do Sul State, Brazil. The treatments were arranged in a randomized block design in a 4 x 4 factorial (application times x herbicide rates), with four replications. The increase in rates of paraquat up to 35 DAF increased linearly the percentage of defective seeds, whereas the seed mass was reduced linearly up to 40 DAF. The yield of the common bean was not affected by paraquat application from the 35 DAF, but the increase in the rate caused linear reduction in this parameter.