Abstract

                                Investigation with 19 parents (4 cent per cent pistillate lines and 15 inbreds) and their 60 hybrids of castor produced through L x T was taken up over four environments (two seasons and two locations) to determine the extent of heterosis for seed yield and seven related traits and to identify the best heterotic crosses for commercial cultivation. The relative heterosis, heterobeltiosis and standard heterosis for seed yield per plant over environments ranged from 1.23 to 148.76, -9.29 to 118.93 and -23.94 to 84.75 per cent respectively. The hybrids LRES 17 x RC 1226, 240 X USSR 2 and JP 65 X JH 120 exhibited maxiinum seed yield (183.2 g. 162.7 g and 158.7 g per plant respectively) with maximum heterosis. The heterosis for seed yield appeared to be due to high manifestation of heterosis for length of primary raceme, racemes per plant, capsules per plant and 100. seed weight. Selection of crosses on the basis of per se performance with considerable per cent of heterosis would be more desirable.

Key words : Castor, Ricinus communis, Heterosis, Environment