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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...

Summary Availability of cost effective mechanism/method to produce large-scale F1seeds utilizing selected parental lines is an important factor, which ultimately determines the commercial viability of the hybrid varieties. In vegetables, although experimental crosses (few seeds for research purpose) can be developed through manual emasculation (in case of hermaphrodite crops) followed by manual pollination of emasculated flowers or pistilate flowers (in case of monoecious crops with separate staminate and pistilate flowers) seed production of commercial hybrids (large quantity of seeds for cultivation) based on such methods is economically feasible only in tomato, eggplant, sweet pepper, cucurbits and few other vegetables, in which a large number of F1 seeds are obtained from one manually pollinated crossed fruits. Ever since (since 1930s) the discovery of male sterility (in onion) and self-incompatibility (in cabbage) mechanisms and their proposed utilization in hybrid seed production, several mechanisms...

Summary Okra is a seed propagated hot weather crop sensitive to frost, low temperature, and waterlogging as well as drought conditions. It is a multipurpose crop due its various uses. It is grown in many countries and cultivars from different countries have certain adapted distinguishing characteristics specific to the country to which they belong. In home consumption India tops the world. Genetic diversity exists for number of characters. Genetic resistance involving interspecific crosses have been exploited commercially for Yellow Vein Mosaic virus. Hybrids are very much popular in this crop and the hybrid seed production is based on hand emasculation and hand pollination. Proper isolation is necessary between two fields of two varieties for maintaining the genetic purity of the stock.

Summary Tomato is one of the most popular vegetable crops grown across the world. Its genetics is much studied among vegetable crops, resulted in the reorganization of its commercial exploitation of hybrid vigor since last hundred years. Tomato has tremendous potential of heterosis for earliness, total yield, resistance attributes and uniformity. Hybrid tomato varieties will continue to predominate high input agricultural systems and may expand under some lower input systems where benefits can be demonstrated. Increasing demand for hybrid seeds can stress commercial hybrid seed production abilities. At present most of the hybrid seeds of tomato is being produced by hand emasculation and hand pollination. The advances in genetic emasculation methods can prove very useful for making the hybrid seed production profitable and ensure the supply of hybrid seed at cheaper rates to the growers.