Vegetative vigour, yield and field tolerance to leaf rust in four F1 hybrids of coffee (Coffea arabica L.) in India

Four F-1 hybrids of arabica coffee (Coffea arabica L.) developed with the primary objective of pyramiding the S(H)3 gene for leaf rust resistance in a commercial variety 'Chandragiri' for achieving the long-lasting resistance to leaf rust, have been evaluated in field. Two hybrids (S.5083 and S.5084) were derived from a donor heterozygous to S(H)3, while the other two hybrids (S.5085 and S.5086) were developed from donor homozygous to S(H)3. Among the hybrids, S.5086 recorded superior yield performance during individual years with a maximum yield of 1611 kg/ha during 2020-21 and the four year mean yield of 1313 kg/ha. The hybrid exhibited maximum heterosis over mid parent (29.10%) and better parent (17.12%) and S.5086 progeny also manifested high field tolerance to leaf rust pathogen as the entire plant population was free from the disease incidence throughout the study period. The findings of the present study established the efficiency of F-1 breeding strategy with simultaneous pyramiding of rust resistance genes for development of vigorous, high yielding and durable rust resistant F-1 hybrids in arabica. The F-1 hybrid, S.5086 with promising performance in terms of crop yield and high field tolerance to leaf rust has potential implications for commercial exploitation.