The Physiological Basis for Yield Differences between Four Genotypes of Groundnut (Arachis Hypogaea) in Response to Drought. III. Developmental Processes

Abstract

SUMMARYRates of leaf development in four groundnut genotypes were found to depend primarily on temperature, although there was a linear relation between the thermal time to produce one leaf and mean leaf water potential below −0.6 MPa. Flower, peg and pod production was analysed in relation to leaf number, since this integrated effects of temperature and water status.When water was not limited, the ratio of pod number: peg number was about 0.8 for all four genotypes. During drought only one genotype (TMV 2) maintained this value, while for the other genotypes the ratio was approximately 0.15. Genotypes also showed different patterns of development during recovery from drought. TMV 2 maintained relatively high values of partitioning factor throughout the pod-filling period, resulting in the largest harvest index and pod yield. Kadiri 3 achieved the second largest harvest index and pod yield by maintaining production of pegs during drought and only forming pods when stress was relieved.