Appraisal of a Chemical-Hybridizing Agent for Emasculation in Rice

Rice productivity can be enhanced through exploitation of heterosis in hybrids with a possible positive impact on food security. Making planned crosses is difficult in rice because of the morphology and size of the inflorescence. This study was undertaken to investigate the efficacy of a gametocide (ethrel) as an emasculating agent. Experiments were conducted at ICRISAT Research Station at Samanko in Mali during 2004–2005. A factorial arrangement in a randomized complete-block design involving three levels of concentrations of the gametocide and five application stages was undertaken for two seasons. Morpho-physiological trait responses and spikelet sterility data were recorded on the female treated plants. Ethrel could induce 40 to 49% male sterility in rice. Percentage of empty spikelets and male sterility increased with increasing concentration of ethrel, reaching a peak between 2,000 ppm (2.0 g L−1) and 4,000 ppm (4.0 g L−1). Male sterility induction of 41.5% and 42.8% at 2000 ppm was achieved in 2004...