Experimental Agriculture

Research Article

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

D. Harrisa1, R. B. Matthewsa1 p1, R. C. Nageswara Raoa2 and J.H. Williamsa2

a1 ODA Microclimatology Group, School of Agriculture, Sutton Bonington, Loughborough, Leicestershire, England

a2 International Crops Research Institute for the Semi-Arid Tropics, Patancheru PO, Andhra Pradesh 502324, India

SUMMARY

Rates 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.

(Accepted September 18 1987)

Correspondence:

p1 Present address: Oxford Forestry Institute, Oxford University, South Parks Road, Oxford, England.

Footnotes

† Submitted as Journal Article No. 656 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).