Abstract

Evaluation of 15 F₁ hybrids and six parents obtained from partial diallel crosses was carried out during 2011 rainy season at Institute of Agricultural Research (IAR) Samaru, Zaria Striga infested field and Striga free field (2 environments). Interrelationships of grain yield and its components under Striga infestation revealed that character ear height had positive and highly significant phenotypic correlation with grain yield (r_ph = 0.55)**. While the remaining six characters recorded no significant correlation with grain yield. Similarly, Striga related parameters with Striga affected traits indicated high and highly significant positive correlation between Striga count one with Striga count two (r_g= 0.79, r_ph = 0.92 and r_e  = 0.96)** and Striga rating (r_g = 0.84, r_ph = 0.71 and r_e = 0.77)** and also had highly significant positive genotypic correlation with number of leaves per plant (r_g = 0.79**) Striga count two exihibited high and highly significant positive phenotypic and environmental correlation with the traits Striga rating (r_ph = 0.78**and r_e = 0.71**) and number of leaves per plant (r_ph = 0.64** and re = 0.55**). While Striga rating recorded highly significant positive genotypic correlation (r_g = 0.89**) coefficient r_ph = 0.78** and r_ph= 0.97** respectively. At Striga free environment grain yield was positively significantly correlated with 1000 grain weight (r_ph = 0.43* and r_e = 0.45*), highly significantly positively correlated at genotypic level (r_g= 0.69)**, phenotypic level (r_ph = 0.52)* and environmental level (r_e = 0.43)* with number of leaves per plant. Furthermore, plant height with grain yield recorded highly significant positive correlation genotypically, phenotypically and environmentally with the following coefficients (r_g = 0.86, r_ph= 0.67 and r_e = 0.58)**, and likewise ear height and grain yield revealed significantly positive correlation with the following coefficients r_g = 0.45*, r_ph = 0.48* and r_e = 0.49*. Thus characters such as ear height, plant height, number of leaves per plant and 1000 grain weight should be taken into cognizance when selecting high yielding genotypes. Hybrids TZEEI 11 x TZEEI 3, TZEEI 11 x TZEEI 7 are outstanding in performance, especially grain yield and TZEEI 11 is good for hybrid formation.

Key words: correlation, Striga parameters, grain yield and Striga affected traits.