In order to identify characters that contribute to yield of groundnut (Arachis hypogaea L.) varieties under the influence of poultry manure and weed control treatments in irrigated condition, field trials were conducted during the 2012/2013 and 2013/2014 dry seasons at the Irrigation Research Farm of the Institute for Agricultural Research, located in the Sudan savanna ecological zone of Nigeria. The treatments consisted of three levels of poultry manure (0, 1.5 and 3 t ha-1), five weed control treatments (54 g a.i. ha-1, 108 g a.i ha-1 and 162 g a.i ha-1 of Haloxyfop-R-methyl ester, weedy check, and two hoe weeding at 3 and 6 WAS) on three varieties of groundnut (SAMNUT 23, SAMNUT 22 and SAMNUT 11). The treatments were laid out in a split plot design with factorial combination of the weed control treatments and poultry manure rates occupying the main plot, while the varieties were allocated to the subplots. The strength of relationship between growth and yield characters was studied using correlation coefficient analysis. The direct, indirect, individual and combined contributions of growth and yield components to total pod yield were determined using path analysis. The results showed that pod yield was positively and highly correlated with number of branches, numbers of pods, pod weight, 100-kernel weight but was negatively correlated with haulm yield. Pod weight had the highest direct contribution which was followed by 100-kernel weight, number of pods, number of branches, plant height and canopy spread in that order, while number of leaves had the lowest direct contribution. The highest percent individual contribution was from pod weight followed by 100-kernel weight, number of pods, number of branches, plant height, canopy spread and number of leaves in that order. The combined effect of pod weight and 100-kernel weight gave the highest combined contribution while the combined contribution of number of branches and number of pod ranked second. The least combined contribution was from number of leaves and number of pods and plant height and canopy spread that resulted in negative values. This study has confirmed that all the growth and yield characters considered made significant contribution to pod yield and thus constitute important characters when breeding for high yielding groundnut varieties.
U et al. (Wed,) studied this question.