SORGHUM-SOYBEAN INTERCROPPING. IX. CUTTING SYSTEMS ON FORAGE YIELD SORGHUM AND SOYBEAN CULTIVARS INTERCROPPED WITHIN THE LINE AND MONOCULTURE OF SORGHUM

Seeking to select in intercropping condition in the line of soybean cultivars and sorghum hybrids with better forage yields, a trial was conducted, in 1997/98, at the Agricultural Department of the Federal Universidade of Lavras, Lavras, MG, in a distrofic Dusky Latosol. The experimental design was a randomized block in a factorial scheme 2x4x4+4 with three replication, consisting of two cutting systems (a single cutting, close to the soil, of both crops at R-5 stage of the soybean, and a two cutting system: the first done 60 days after emergence, at 30 cm from the soil surface and the second after the plants regrowth, close to the soil, at the same time of the cutting of the first system); four soybean cultivars (CAC-1, Conquista, Cristalina and Doko RC) and four hybrids of forage sorghum (AG 2002, AG 2005E, BR 601 and Massa 03). Another contiguous trial was conducted for the respective monoculture of sorghum, being realized the cutting of the plants with grains in mealy stage. In the intercropping, the differents cutting systems showed significant differences in yields, green mass, dry matter and total grude protein. The soybean cultivars (CAC-1 and Conquista) and the sorghum hybrids (AG 2002 and BR 601) were the ones that more stood out. In the intercropped system the combinations of better performance were 'CAC-1' x 'BR 601' and 'Conquista' x 'AG 2002' for total grude protein and 'Doko' x 'BR 601' and 'CAC-1' x 'BR 601' for total green mass. In the monoculture the AG 2002 and BR 601 hybrids presented the largerst yields of green mass, dry matter and total grude protein.