VEGETATIVE AND QUALITATIVE PERFORMANCE OF FORAGE SORGHUM (Sorghum bicolor X Sorghum sudanense) CULTIVATED IN CUTTING MANAGEMENT

The trial aimed to evaluate the associative effect of forage sorghum hybrids (Sorghum bicolor x Sorghum sudanense: AG 2501C; XBS 79001; P 855F and BRS-800) and period of evaluation during the growing season (40, 75, 110 and 145 days after planting) on productive and qualitative performance of the forage plant cultivated, under cutting management. A randomized blocks design with four replications was used, in a 4x4 factorial scheme. The factors hybrid and date of evaluation interacted (P>0.05) on dry matter production, participation of stems and leaves in the plant, dry matter, crude protein and neutral detergent fiber contents of the whole plant and the components stems and leaves. The acid detergent fiber contents (ADF) of leaves and whole plant presented quadratic response, with the point of maximum concentration of ADF at 98.97 and 73.75 days, respectively, regardless the sorghum hybrid evaluated, while for stems the response was quadratic with minimumADF point at 76.04 days. The hybrids showed variability for leaf/stem ratio, dry matter production and quality of the structural components of the plants within the productive cycle, and summative evaluation of the parameters indicated that the hybrid P 855F was the most stable under cutting management for ruminant feeding.