NITROGÊNIO, REGULADOR DE CRESCIMENTO E DENSIDADE DE SEMEADURA AFETANDO A PRODUTIVIDADE E A QUALIDADE INDUSTRIAL DO TRIGO

Abstract

Wheat is one of the world's most important cereals and is a staple food for about a third of the world's population, providing more protein than any other cereal. The overall challenge for the wheat production chain is to increase grain yield and industrial quality. Wheat yield and quality can be compromised by several factors that occur in the field, such as cultivation, management, lodging, and soil and climate conditions. In order to evaluate the effect of nitrogen application times on cover, seeding densities and application times of the growth regulator and the influence on grain yield and industrial quality, twelve experiments were carried out, differing in the management, cultivar and Year of cultivation, in the School Farm of the State University of Ponta Grossa, in the Ponta Grossa, PR, Campos Gerais, in the year 2013 with repetition in 2014. The experimental design used in the different times of nitrogen application in coverage, for each cultivar (Gralha Azul and BRS-Pardela) was randomized blocks with 6 treatments and 4 replicates. The treatments consisted of six times of nitrogen application in cover, at 0, 10, 20, 30, 40 and 50 days after sowing. The dose used was 100 kg ha-1 of N as urea (222 kg ha-1). The experimental design used in the different sowing densities, for each cultivar (Gralha Azul and BRS-Pardela), was randomized blocks with 6 treatments and 4 replicates. The treatments consisted of six sowing densities, with 150, 300, 450, 600, 750 and 900 plants per square meter. The experimental design used in the different application times of the Trinexapac-ethyl growth regulator for each cultivar (Gralha Azul and BRS-Pardela) was a randomized complete block with 4 treatments and 4 replicates. The treatments consisted of three application times, in the tillering, between the 1st and 2nd node perceptible, between the 2nd and 3rd node and control. The cultivation system used was no-till in the straw, and soybeans were the predecessor crop in the two years of research. In the anthesis phase, the number of tillers was evaluated; Length and width of the leaves and height of the mother plant. At physiological maturity, the number of ears per meter and spikelets per ear were evaluated; The number of grains per spike; Mass of one thousand grains and apparent harvest index. When the grains reached the harvest point, yield and lodging index were estimated. From the harvested grains, the hectolitric weight (PH) and Falling Number (NQ) were determined. Based on the results found, it can be concluded that the application of nitrogen under cover in the tillering phase provided higher productivity in the wheat crop. The time of N application did not affect the pH and NQ, since this response is also related to the interaction of the cultivar and the environmental conditions. The different sowing densities affect yield in the wheat crop, with the best densities being those recommended by official research. The different sowing densities did not affect the PH and the NQ, and this response could also be related to the interaction of the cultivar and the environmental conditions. The times of application of Trinexapac-ethyl did not provide greater yield in the wheat crop. The time of application of the regulator affected the values of PH only in one year and did not affect the values of NQ, this response could be related to the interaction of the cultivar and the environmental conditions.