Abstract

New rice for Africa (NERICA) 1 and 2 are rice types recently introduced to upland farmers of West Africa by AfricaRice. Farmers in Ghana usually intercrop rice with other crops such as cowpea. The new rice types however have not been assessed for their suitability as intercropping partners of the other crops (for example, cowpea) grown in the savannah uplands of Ghana. Experiments were conducted at the upland rice experimental fields of the CSIR-Savanna Agricultural Research Institute (CSIR-SARI) in June 2008 and 2009 to determine appropriate cropping systems for cowpea and NERICA. The treatments composed of four intercropping systems, viz, sole cropping, strip cropping, alternate rows cropping and alternate hills cropping in a randomized complete block with three replicates. The results indicated considerable variations in yields and yield components of NERICA 1 and 2 in the presence of a companion crop, cowpea. Alternate rows of NERICA and cowpea consistently gave higher numerical cowpea grain yields, although not significantly different from the other intercrops. Yields of cowpea in partnership with NERICA 2 were generally higher than when partnered with NERICA 1. Economic analysis indicated that, given the choice of NERICA varieties, rice farmers who prefer NERICA 1 will have a better return to investment with alternate hills intercropping system while those who prefer NERICA 2 will be better off with the strip cropping system. Cowpea farmers on the other hand are better off with the alternate row cropping system.

Key words: Land equivalent ratios (LER), new rice for Africa (NERICA), sustainable cropping systems, Vigna unguiculata L.