Boron and nitrogen effecton the maize crop

Abstract

This paper evaluated the micronutrient boron and its influence with nitrogen on com crop. The experiment was cany out in area of ESALQ / USP, agricultura1 year of 2000/2001, being used the com hybnd Cargill 909. The experimental design was completely randomized blocks with fifteen treatments and three repetitions, where the boron was applied at sowing moment, associated or not to nitrogen. A11 blocks received, at sowing time 80kg.ha-1 of P2O5 and 60kg.ha-1 of K2O. The measured parameters were number of spikes for plant, spike length, number of grains per row, number of grain rows in the spike, grain length, mass of thousand grains and productivity of grains. In agreement with the obtained results it was ended that the nitrogen application in growing doses provided increase of productivity. The maxim productivity (9182kg.ha-') was obtained using 202,6kg.ha-1 of N, which is not recomrnended in relation to the application of 120kg.ha-' of N. High doses of boron (up to 8kg.ha-1) applied in the sowing did not influence the productivity, concluding that in the present conditions, the phytotoxicity risk provoked by the excess of that element in the sowing is minimum.