Evaluating groundnut (Arachis hypogaea L.) seed yield determinants in northern Ghana A breeding perspective

English

The direct and indirect effects of groundnut physiological responses on seed yield were investigated with genotypes of a wide range of maturity periods in advanced replicated yield trials. The trials were conducted at four locations in the savanna zone of Ghana in the 1996 and 1997 cropping seasons. The objective of the trials was to enhance selection efficiency by concentrating on trials which increase seed yield. In 1996, 27 genotypes of groundnut of different maturity groups were grown. However, in 1997, 22 out of the 27 genotypes used in the previous year were used. The partitioning coefficient, crop growth rate, reproductive duration, shelling percentage biological and seed yields were determined. The path coefficient analysis for both years indicates strong, direct effects of photo-assimilate partitioning to pods and crop growth rate on seed yield. The direct effect of reproductive duration was positive but relatively weak while the biological yield had negative direct effect on seed yield. The efficiency of photo-assimilate partitioning to pods and crop growth rate in determining seed yield were assessed through a regression analysis for each year. This analysis showed highly significant portions of the total variation of the two traits. The results suggest that long reproductive duration, slow crop growth rates, high biomass production, and low dry matter partitioning to pods do not match the ideotype of groundnut species adapted to most of the ecologies of northern Ghana.

Marfo, K. O.; Padi, F.