Abstract
Four rainfed upland experiments were conducted in Benin to assess yield differences in 65 rice varieties, including the interspecific hybrids: the upland New Rice for Africa (NERICA) varieties developed from crossing Oryza sativa L. and O. glaberrima Steud.. The mean grain yields ranged from 32 to 350 g/m2 across experiments. The genotype × environment (G×E) interaction accounted for 15% of the total sum of squares, with environment and genotype responsible for 74 and 12%, respectively. Upland indica B6144F-MR-6-0-0 performed well in three out of four environments, showing consistently higher yields than other upland NERICA varieties and their parents. Upland indica Aus257 was stable across environments with good adaption to poor soil fertility. None of the upland NERICA varieties showed consistently higher yields than their parents across the four environments. The group of long-duration varieties (e.g. IR 8, IR 24, Taichung Native1) performed well only in most-favorable environments. The high-yielding varieties B6144F-MR-6-0-0 and Aus257 were intermediate in panicle number (160–180 panicles/m2 on average). This was the only common characteristic among the highest yielding varieties. These results suggest that further increases in rice yields in the rainfed uplands of West Africa are most likely to occur through using upland indica varieties as donors.
