The study was conducted at Teaching and Research Farm, Faculty of Agriculture, Bayero University, Kano (Lat 11 0 59`N, Long 8 0 25`E and 466m above sea level), during 2016 rainy season, to determine the variability, heritability and correlation among the soybean varieties. The treatments consist of eight soybean varieties, laid out in Randomized Complete Block Design (RCBD) and replicated four times; varieties were evaluated for fifteen characters to determine variability, estimate heritability and correlation. Analysis of variance revealed significant difference (P>0.01<0.05) with respect to four characters and highly significant (P≤0.01) four seven characters. The results indicated the presence of substantial variability among the varieties. GCV, PCV, ECV and heritability estimates ranges from 0.000039-169.18, 0.000066-187.55, 0.000053-122.28 and 0-100% respectively, the high Genotypic Coefficient of Variation (GCV), Phenotypic Coefficient of Variation (PCV) and Environmental Coefficient of Variation (ECV) observed in this study indicated the existence of variability and selection can be done. Whereas high estimate of broad Sense heritability for the tested parameters indicated that these characters were highly heritable and selection can be imposed. Significant phenotypic correlation for GWha and FWha with FWP respectively revealed that, these characters were primarily influenced by their direct contribution to higher yield. It is therefore recommended for an effective selection of those characters could be adopted for cultivar improvement and hybridization program and more research is needed to validate the findings.

Experiments were conducted at the Teaching and Research farm of the Department of Crop Science Kano University of Science and Technology, Wudil and on a farmer’s field at Dambatta Local Government Area, with eight maize genotypes to assess the character associations among the genotypes for yield attributes. The experiment was conducted during February to June 2021 and also 2022, in a lattice design with three replications in both years and locations and are made to determine the performance of the genotypes in interacting environments. The genotypes differed significantly for most of the studied traits. Grain yield was significantly associated with plant height, anthesis silking interval, days to maturity, ear height, ears per plant, grain weight per plant in a positive direction and associated negatively with tassel blast, barren plant and leaf senescence. Path co-efficient analysis revealed that the maximum positive direct contribution towards yield was through grain weight per plant, plant height, and ears per plant whereas ear height showed negative direct contribution to grain yield due to negative indirect effects of several other parameters such as ear height via grain weight per plant, plant height via grain weight per plant.

Drought stress and heat stress are two major limiting factors affecting maize productivity in the tropical regions. High temperatures and changes in rainfall pattern can cause significant decline in maize yields under rain fed conditions with Africa being one of the worst affected areas. Heat tolerance can be accomplished through genetic management approach. The aim of the research is to assess the extent of variation in tolerance to drought stress and heat tolerant stress and their performance on growth and yield characters. The trials were conducted on genetic analysis of Maize (Zea mays L.) inbred lines under combined (drought and heat stress) conditions. The parental materials comprises eight inbred lines that were crossed in a partial diallel pattern; thereafter, the checks, parents and resultant F1 generations were evaluated at two locations, Kano University of Science and Technology and farmers field at Dambatta local government area Kano state during 2021 dry seasons. The experiment was laid out in a randomized complete block design and replicated three times. The results indicated the crossing of P4 X P9 and P3 X P4 to produce significantly to produce significantly better growth attributes like plant height ear height, plant aspect and grain yield. These parental lines might be used in maize breeding programs in Nigeria as sources of drought and or heat tolerance.

Field trials were conducted during the rainy season of 2017 at Teaching and Research Farm of Bayero University and Kano State Livestock development Centre Dangora. To determine the magnitude and nature of the association between growth characters and grain yield of maize, as well as the percentage contribution of each of this independent variable on the dependant variable (yield).The trails consist of six weed control methods, three levels of poultry manure and three varieties of maize. The experiment was laid out in a split-split plot design with variety allocated to the main plot, poultry manure to the sub-plot while weed control method to the sub-sub plot, and was replicated three times.  Grain yield correlated positively and significantly with growth and yield characters evaluated while weed dry weight and weed index were highly negatively correlated. The direct and indirect contributions results indicate that plant height had the highest direct contribution at BUK and Dangora in 2016 and Doka 2017 while plant dry matter accumulation had the highest direct contribution at Dangora in 2017. Cob diameter had the least direct effect in the study; the highest indirect effect was from cob diameter through plant height. The percentage individual contribution to grain yield showed that plant height made the highest contribution at BUK and Dangora in 2016, while cob diameter at both locations and plant dry matter at Dangora resulted in the least contribution. The combined contribution of dry matter and 100-seed weight was the highest positive contribution at BUK and that of plant height via 100-seed weight all in 2016 while cob length via 100-seed weight made the least negative contribution at BUK.

ABSTRACT