BROADCASTING NITROGEN IN NO-TILLAGE OF SUNFLOWER: I - GRAIN YIELD AND ITS COMPONENTS, HARVEST INDEX AND OIL CONTENT

Abstract

This work was carried out in the agricultural year of 1998/99, with an objective to evaluate the effect of different levels of broadcasting nitrogen in the sunflower production (Helianthus annuus L.) in notillage system. The experiment was driven at Fazenda Agripastos, in Palmeira, region of Campos Gerais, Paraná, in a red-yellow argissol, cultived as no-tillage system since 1976. The experimental design used was a randomized completely blocks with four replications. The treatments were: rates of nitrogen (0, 25, 50, 75, 100 and 125 kg.ha-1), in the urea form, applied in broadcast when the plants were met in the V8 stage. The hybrid M734 was sowed in September, 1998. The following parameters were evaluated: grain yield, apparent harvest index, weight of 1000 achenes, achenes number per capitulum and oil content in the achenes. The nitrogen fertilization in broadcast, in the conditions of the experiment, didnt present any increase in the grains and any changing in its components and the achene oil content.