Studies on heterosis in sponge gourd

28 F1 hybrids of sponge gourd in a diallel set involving 8 parental lines were studied to assess the extent of hybrid vigour in the yield contributing traits. The mean values of hybrids was greater than those of parents for all the characters except the fruit maturity. The increase yield in heterotic hybrid ranged from 20.0 to 90.7 percent. The maximum and significant heterosis was recorded in P2×P4 for vine length, P2×P9 for fruit length, P2×P5 for fruit/plant, P4×P7 for average fruit weight and P2×P4 for total yield. In all the characters, the best performing hybrid was significantly better than the top parent. In order of merit P2×P4 P6×P5 and P2×P8 were best F1 hybrid for total yield and its many component characters. The best parental combination was found to be P2×P4 (IIHR-9 and IIHR 23) which exhibited 90.78 percent increase over better parent and 72.78 percent increase over top parent. Thus, IIHR 76 can be utilised for exploitation of hybrid vigour in sponge gourd.