Pre-harvest desiccation in grain sorghum: physiological seed quality and effect on regrowth

Abstract

The use of pre-harvest desiccants in sorghum can make this step in the field more agile and efficient. However, herbicide application on the crop poses risks to seed germination and vigor. In this context, the desiccant effect on harvest anticipation, the physiological quality of the seeds and the control of regrowth in grain sorghum were studied. The experiment was conducted in a factorial scheme (2 x 4) +1, with two herbicides glyphosate (Roundup original) and paraquat (Gramoxone 200) with two doses (0.5, 1.0, 2.0 and 4.0 L ha-1 of the commercial product) plus the control control (without application) in the randomized block design. The harvests were: anticipation of the harvest, first germination count, germination, water content and electrical conductivity of the seeds and control of plant regrowth. Paraquat allows an anticipation of the harvest in up to 14 days and when it is used in the doses of 2.0 L ha-1 not harmful to the germination of the seeds and, therefore, a contact herbicide, it is not necessary to make a control on a regrowth of sorghum plants. Glyphosate, because it is a systemic herbicide, exerts efficient control of sorghum regrowth and allows harvesting in up to 12 days.