Níveis de nitrogênio e épocas de decapitação: influências no perfilhamento, produção e em algumas característica do arroz (Oryza sativa, L.)

Abstract

An field experiment to study the effects of nitrogen levels and time of cutting on tillering, yield and panicle characteristics of upland rice (õtiyza òativa, L.) was carried out at the Escola Superior de Agricultura de Lavras, in Lavras, Minas Gerais, Brasil. Five nitrogen levels (0, 30, 60, 90 and 120 kg de N/ha) and cuttings at 10, 20, 30 and 40 days after emergence with a control (no cut) were tested. A randomized split-plot design with four replications was used. The nitrogen levels were assigned to the plots and cuttings were assigned to the subplots. The IAC-47 rice variety was used. The weight of full grains per panicle, decreased with an increase in cutting time; the nitrogen levels increased panicle length, number of branches per panicle, number of tillers per plant and plant height: the number of plants per plot increased with increasing nitrogen levels for the 20 days cutting. The grain yield increased when increasing nitrogen levels were applied to no cut plants.