BORON FOLIAR APPLICATION ON SUNFLOWER (Helianthus annuus L.) ASSOCIATED WITH HERBICIDES

SUMMARY The present work was undertaken to evaluate volunteer corn control through the application of graminicides singly or combined with boron (B) sources as well as to assess the sunflower (Helianthus annuus L.) response to the application of this micronutrient. Experiments were arranged in a split-plot design with randomized complete blocks and five replications. The treatments applied were haloxyfop-methyl 0.048 kg a.i. ha -1 plus 0.5% (v/v) mineral oil, sethoxydim 0.22 kg a.i. ha -1 plus 0.5% (v/v) mineral oil, clethodim 0.12 kg a.i. ha -1 plus 0.5% (v/v) mineral oil, fluazifop-p-butyl 0.187 kg a.i. ha -1 and the hand-hoed control. The sub-plots consisted of the absence or presence of 400 g ha -1 of B from two sources (H3BO3–boric acid and Na2B8O13.4H2O–sodium borate), applied with the herbicides. All herbicides applied singly or combined with the two B sources were selective for the sunflower crop and efficient in controlling volunteer corn. The application of B in association with herbicides increased the content of this micronutrient in sunflower leaves.