Correlation and Path Analysis Studies of Stalk Lodging Resistance, Grain Yield and Related Agronomic Traits in Different Maize Varieties

Abstract

Twelve maize varieties of different years of release were grown at Bako in a plot size of 15.3 m2 using the RCBD design under rain fed condition at Bako.  The objectives were to assess the degree of variation of maize genotypes for stalk lodging resistance and to estimate correlation among stalk lodging,  grain yield, and yield related traits. There were significant differences among genotypes for stalk lodging (P<0.01). Even though there were significant  difference (P<0.01) for grain yield among genotypes most of the genotypes performed below their potential, except BH-541 due to the late onset of  rainfall and terminal drought stress, which disfavours the full expression of genetic potential. A relatively high value of phenotypic coefficients of  variation was observed for stalk water content, grain moister content, ear height, and stalk lodging percentage. The correlation values though high, were  non-significant for most of genotypes due to the small number of experimental material tested. The dependent characters yield and stalk lodging  correlated negatively at phenotypic and environmental level. Both grain yield and stalk lodging showed positive direct effect with grain moisture content  (1.3817, 1.7844), ear height (6.9566, 8.9841), major stalk diameter (0.4912, 0.6344), minor stalk diameter (0.0912, 0.1178), ear length (0.4152, 0.5362) and  stalk water content (0.4386, 0.5664) at phenotypic level. Correlations of grain yield with major stalk diameter (rp=0.7056) and with ear length (rp=0.5999)  was positive and in a desirable direction, while Correlations of stalk lodging with major stalk diameter (rp=-0.3713) and with ear length (rp=-0.4332) was  negative and in a desirable direction, so improving these traits directly improved grain yield and decrease stalk lodging but restricted simultaneous  selection of other indirect traits would be important especially when we practice direct selection through major stalk diameter and ear length; hence, the  positive contributor traits grain moister content, ear height, minor stalk diameter, stalk water content ignored while plant height, ear height to plant  height ratio should be considered. Among the genotypes, BH-541 was found to be ideal since it has the highest values for both major stalk diameter and  ear length.