Storage behaviour of two contrasting upland rice genotypes

Abstract

This study investigated complaints by upland rice farmers in Ghana that their local rice cultivar "Kawomo" (Oryza glaberrima) stored better than an improved upland rice cultivar, IDSA 85 (Oryza sativa subsp. japonica), tested and selected in a Participatory Varietal Selection programme. One seed lot of "Kawomo" and two seed lots of IDSA 85, differing in initial quality, were stored hermetically at 50 oC with five (18, 15, 12, 10 and 8%) moisture contents. In the second investigation, seed of "Kawomo" was stored hermetically at the above moisture contents, but at 30 oC. Both investigations were carried out at the Seed Science Laboratory, Department of Agriculture, The University of Reading, UK. In the third investigation, 122 samples of farmer-saved seed were stored hermetically at moisture contents between 12 and 16 per cent under ambient temperature in Ghana for 6 months. Seed moisture content had a significant (P <0.001) effect on the rate of seed deterioration. Although the negative logarithmic relation between longevity and moisture content did not differ significantly (P >0.10) among the two species, glaberrima rice showed marginally greater longevity than japonica rice. The viability equation also accurately predicted germination of farmer-saved seed stored under ambient (fluctuating)
temperature in Ghana.