Yield and yield components of lowland rice (Oryza sativa L.) as influenced by different management practices in Guinea savanna ecological zone

Abstract

To study the influence of weed management practice, seeding method and seed rate on the yield and yield attributes of rice (Oryza  sativa L.), a field experiment was conducted in 2012 and 2013 wet seasons at the Irrigation Research Stations of the Institute for  Agricultural Research, Ahmadu Bello University, Kadawa, Northern Guinea Savannah Zone of Nigeria, The treatments consisted of four  weed management practice (Oxadiazon at 1.0 kg a.i ha^-1 [preemergence], Orizoplus [premix- propanil 360 g/l + 2, 4-D 200 g/l] at 2.8 kg a.i  ha^-1 [post emergence at 3 WAS], manual weeding [at 3 and 6 WAS] and Weedy check); three each of seeding methods (Drilling,  Dibbling and Broadcast) and seed rates (40, 70 and 100 kg ha^-1). The experiment was laid in a split plot design replicated three times.  Weed management practice was allocated to the main plots while seeding method and seed rate were factorially combined and allocated  to the sub-plots. The general trend in this study revealed that paddy yield was enhanced when plots were weeded twice compared to other weed management practices. Broadcast method of seeding had significantly lower values for yield attributes and  paddy yield when compared with drilling and dibbling seeding methods at both years of study. In 2013, the highest paddy yield was by  drilled (3441 kg ha^-1) or dibbled (3483 kg ha^-1) manually weeded at 3 and 6 WAS and by drilled (3433 kg ha^-1) or dibbled (3528 kg ha^-1)  rice treated with oxadiazon at 1.0 kg a.i ha^-1). From the study, it was observed that the use of optimum seed rate of 70 kg ha1 in  combination with either manual weeding at 3 and 6 WAS or oxadiazon at 1.0 kg a.i ha^-1 and drilling or dibbling was promising in rice  production in the Nigerian Northern Guinea Savannah ecological zone.