Application period effect of nematicides in sugarcane ratoon on nematodes populations and sugarcane yield

摘要

The objective of this work was to define the best period of nematicides application in sugarcane ratoon, Six experiments were carried out in the sugarcane field harvested from July through November during which nematicides were applied at 5, 20, 40 or 60 days after harvesting. Nematicides contributed to increase yield in five of the six experiments. In the experiment in which yield increase was not observed, nematode population was low. The three nematicide treatments (aldicarb 150G at doses 8 kg.ha(-1) or 10 kg.ha(-1) and carbofuran 100G 21 kg.ha(-1)) promoted similar reductions in the nematode populations and yield increases. In the experiments harvested during the dry season, higher productions were obtained when nematicides were applied at 40 or 60 days after the harvest and, in the experiment harvest at raining season, the highest production was obtained when the nematicides were applied at 20 or 60 days after harvesting. These results suggest that the period following harvest that must be waited before applying nematicidas in sugarcane rations, in order to obtain the best yield increase, varies with the sugarcane harvest time; being best from 40 to 60 days after harvesting in the dry season and 20 days at raining season.