Agronomic performance of canola submitted to desiccation with herbicides at different maturation stages

Desempenho agronômico de canola submetida à dessecação com herbicidas em diferentes estádios fenológicos da maturação

ABSTRACT

Uneven maturation in canola is an important challenge for its management in regions subject to frost and high rainfall at the end of the cycle. In order to identify practices to maximize grain yield under these growing conditions, this work evaluated the effects of desiccation with herbicides at different phenological stages on Hyola 433, one of the most commonly used hybrids in Brazil. The experiment was conducted in a randomized block design with four repetitions in a 6 x 4 factorial scheme, with five herbicides: paraquat, diquat and ammonium glufosinate at dose of 400 g a.i. ha^-1, glyphosate at 1,440 g a.i. ha^-1 and saflufenacil at 70 g a.i. ha^-1, plus the control, at four phenological stages of silique maturation (G₂, G₃, G₄ and G₅). Desiccation at G₂ and G₃ reduced the oil content and thousand-grain weight on average by 60%, affecting directly grain yield. Desiccation at G₄, regardless of herbicide, did not influence thousand-grain weight and oil content, but the use of diquat reduced canola yield by 187 kg ha^-1. In the desiccation at G₅, none of the herbicides led to differences compared to the control for thousand-grain weight, yield and oil content, and it allowed harvest to be brought forward by five days. In general, the crop presents adequate responses to the desiccation with different herbicides at the phenological stages G₄ and G₅.

Key words:
harvest antecipation; grain yield; oil content