CROP IMPROVEMENT STUDIES IN CASHEW (ANACARDIUM OCCIDENTALE L.)

The general combining ability effects of thirteen genotypes of cashew were studied, using ten parents as testers and three as lines in a Line Tester mating design at the Regional Research Station, Vridhachalam, Tamil Nadu. The parents along with their thirty hybrids were studied for the expression of heterosis for germination percentage and vigour index. High relative heterosis of over 100% was observed in three cross combinations. For vigour index, the maximum relative heterosis of 62.80 was observed in M 44/3 × PU6. The parents M 44/3, M 3/2 and M 33/3 were good general combiners of germination percentage while M 10/4 and M 33/3 were the good general combiners for vigour index. The cross combination M 26/2 × M 15/4 exhibited the highest sea effect with high mean performance. The cross combinations M 26/2 × M 15/4 and M 33/3 × M 26/2 with high mean expression and high sca effects for vigour index offered scope for further exploitation of hybrid vigour.