POTASSIUM DOSES AND APPLICATION IN THE DRY BEANS PLANT WITH NO TILLAGE SYSTEM

Abstract

In the agricultural years of 1997/98 and 1998/99 were conducted in Fazendas Santa Terezinha and Estiva II in Tibagi, PR, two field experiments with the objective of evaluating the answer to different potassium doses (00, 30, 60, 90 and 120 Kg/ha of K2O) and two application manners (line and throw), in the variety type III (common carioca) in system of direct plantation in the straw. The experimental design was randomized complete blocks in a factorial arrangement 2 x 5 with four replications. Each plot contained eight lines of seven meters in lenght and spacing of 0,45 cm among lines, with a total area of 25,20 m2. Were picked the four central lines, being despised 1,0 m as a border in each extremity of the plot, using as useful area of 4,5 m2. In each treatment in the stadiums of development R5, R6, R7, R8 and R9 were sampled tem plants of the lateral lines of the useful plot, and cut near to the soil, for the dry matter evaluations. In each treatment were collected in 20 plants three leaves matured in the beginning of the flowering (R6), to evaluate the potassium content in the tissue. The experiment conduction was accomplished with preventive applications of insecticides, fungicides and the weed plants were controlled in agreement with the infesting species. In the two years of the metereological point of view, during the cycle of the culture the maximum and minimum temperatures, and the precipitations were considered as typical of the area, that is to say, without extreme temperatures and withour lack or excess of water in the critical phases of the culture. At the harvesting time were evaluated the yield and its components, height and final population of plants. The common variety carioca, in two experimental years didnt answer to the different potassium doses and the two application manners for yield and its components, dry matter accumulation in the stadiums R5, R6, R7, R8 and R9, plant height and content in the leaves tissues showing that, even for high productivities, if climatic conditions show favorable, the plant in system of direct plantation in the straw can be supplied by the reservation accumulated in the surface of the soil, in function of the constant replacement of the cultures predecessors residues.