Performance of sorghum hybrids, as surnmer forage, sown on clayey soil of the Maule region

Jorge González U.1, Germán Klee G.1, Patricio Soto O.1

The dry matter (DM) yield and quality of five hibrid fooder sorghum: Sudax ST-6 (I), Sudán Cross 3 (II), Trudán 8 (III), Sucro Sorgo 405 (IV) and Suero Sorgo 301 (V) were evaluated from November to April (1988/89 qrowing season) under irrigated land conditions. Twenty five kg/ha of seed rate were sown in lines at 0.5 m aparto Nitrogen (117 kg/ha), P (48,5 kg/ha) and K (48 kg/ha) were applied at sowing. After the first and second cut 60 kg/ha of N were applied. The plots were irrigated five times between December and March. A randomized block design with 5 treatments and 3 replication was used. The plants were cut when they reached 60 cm high and 5 cm of stubble were left. The sampling two area was 5 x 2.5 m (12.5 m2). Dry matter production, leaf: stem ratio, crude protein (C.P.), acid detergent fiber (A.D.F.) and total digestible nutrients (T.D.N.) were measured. Dry matter yield per cut and total of five hibrid were not different (P > 0.05), except at the firsí cut when the treatments I (Sudax ST-6) and V (Suero Sorgo 301) had higher (P > 0.05) yield (3.14 ton/ha of D.M.) than the treatments III and IV. Yield per cut and total dry matter showed no differences (P < 0.05) among hibrids, except for the yields obtained in the first cut where treatments I (Sudax ST-6) and V (Sucro Sorgo 301) had greater yields (P < 0.05) with a top of 3.14 ton m.s./ha in relation to híbrids III (Trudán 8) and IV (Suero Sorgo 405). Stem contríbutíon to the total dry matter yield and acid detergent fiber showed differences between sorghums (P < 0.05). However, leaf contribution, crude protein and total nutrients were statistically the same (P < 0.05).

1 Estación Experimental Quilamapu (INIA), Casilla 426, Chillán, Chile.