EFFECT OF SEEDBED TYPES, UREA FERTILIZER RATES AND INTERCROPPING OF SORGHUM WITH LEGUMES ON STRIGA INCIDENCE AND SORGHUM YIELD

Abstract

These studies were conducted at Damazin Research Station, Damazin, (Latitude 11 0 47’34N, longitude
340 21’55 E) and approximately 343.01 meters above sea level (MSL) for two consecutive seasons of
2006/07 and 2007/08. Three types of seed beds were used namely, flat (control 1); normal ridged and tied
ridged in a Striga infested field trial. The objectives were to test for the incidence of witch weed (Striga
spp.) and performance of sorghum under the different treatments. The treatments were: two rates of urea
fertilizers applied at 103.5 and 207.0 kg/ha; four leguminous plants namely, Bambara nuts, (Vigna
subterranea L. Verdc.; Groundnuts, (Arachis hypogoea L.); Clitoria, (Clitoria ternatea); and Desmodium
spp.) were intercropped with sorghum, Sorghum bicolor L. Moench (cv. Wad Ahmed) and a sole
sorghum without any treatment (control 2) were compared for their effect on Striga population at 8 and
12 weeks after sorghum emergence (WASE); Striga dry weight at harvest; sorghum height and sorghum
grain and straw yield. Results showed that normal ridged seedbeds reduced Striga population and its dry
weight effectively. Amongst the legumes intercropped with sorghum, Clitoria spp. reduced sorghum
height considerably, and the application urea fertilizers regardless of the rates used, increased sorghum
grain yield as well as Striga population.