EFFECT OF CORN (ZEA-MAYS) GENOTYPES WHICH VARY IN MATURITY LENGTH ON STRIGA-HERMONTHICA PARASITISM

Corn (maize) genotypes which varied in days to maturity were evaluated for level of Striga hermonthica parasitism in western Kenya during th ree seasons. Fifteen genotypes, with a wide range in days to maturity, were grown in fields heavily infested with S. hermonthica. Early and late-season Striga numbers and corn grain yield were used to evaluate Striga parasitism. There was considerable variation in the timing and amount of Striga attachment among seasons. Days to silking and late-se ason Striga numbers were correlated (P less-than-or-equal-to 0.05) in all experiments although only weakly in one of the experiments. Grain yield was negatively correlated with days to silking in two of three e xperiments as were yield and early season Striga numbers. Although ear lier-flowering genotypes consistently supported less Striga, they did not always yield more than the later-maturing genotypes due to confoun ding effects of yield potential and adaptation. There was considerable variation in Striga parasitism among genotypes within maturity groups , and the relative response of genotypes varied between seasons. These data suggest that in some seasons early maturing genotypes have poten tial to reduce Striga attack in heavily infested areas and yield more than later-maturing genotypes.