With the objective to evaluate the influence of different times of sowing in the productivity and silage quality of corn and sorghum cultivars and also of verifying the possibility of substitution of corn to sorghum to silage production, experiments were installed considering three times of sowing in area of the Department of Agriculture of the Federal University, during the agricultural year of 2002/2003. Three groups had been evaluated to cultivars (three of double purpose sorghum, three of forage sorghum and three of corn) at three times of sowing (19/11/2002, 19/12/2002, and 18/1/2003). The experimental design was of blocks randomized in factorial scheme 3 groups to cultivars (to cultivars) x 3 times of sowing (times), with four repetitions. Productivity of dry matter was evaluated (MS), participation of panicle or spike in the MS, and the rude protein percentages, fiber in neutral detergent, fiber in acid detergent and lignin. Significant effect was observed to cultivars, times of sowing to all characteristics evaluated. The presence of interaction cultivars*times was verified for the productivity of dry matter, participation of panicle or spike in the MS and the rude protein percentages. Independently of times of sowing, with the corn present silage with smaller fiber tenor than with any sorghum types, and productivity of dry matter similar to the one of forage sorghum and superior to the one of sorghum of double intention. The largest production of dry matter of corn and sorghum was obtained when the sowing is made in November. Corn and sorghum silage of larger nutritional value was obtained when the sowing was made in January. Under the production point of view and of quality nutritional of the forage, it is not viable the substitution of the corn for sorghum.
Zea mays; Sorghum bicolor; Crude protein; NDF; ADF
