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Some level of variation within crop varieties is highly important for its improvement with the aids of good plant breeding methods. A field research experiment was carried out with the aim to estimate genetic variation and heritability in the okra accessions grown in different agro-ecological zones in Nigeria. Twenty okra accessions were obtained from various locations in different agro-ecological zones of Nigeria. Twenty okra accessions were evaluated between April to August 2018 at Ekiti State University Teaching and Research Farm, Ekiti State. These twenty okra accessions constituted the treatment, which was lied out in a RCBD in a three replicates. The result were highly significant (p<0.01) for all the traits studied. Magnitude of the phenotypic coefficient of variances were slightly higher than genotypic coefficient of variances in this study which showed that environment did not much influence the estimates of genetic performance. The coefficient of phenotypic and genotypic variances were high in the traits studied. Heritability estimates ranges from 75.04% for days to 50% flowering to 98.85% for weight of 100 seeds. High heritability with high genetic advance were observed for all the studied traits indicating that they are governed by additive gene action and this could be improved through simple selection except days to 50% flowering with the lowest heritability value coupled with the lowest genetic advance value lesser than 10%.

Experiments were conducted at the Federal College of Agriculture, Akure in 2015 and 2016 to evaluate yield response of four improved cassava (Manihot esculenta, Crantz) varieties. The experiment was set up in a 4 x 2 x 2 factorial experiment comprising of four cassava (TME 419, TMS 98/0581, 98/0505 and 30572), two planting dates (May and June) and year of planting (2015 and 2016). Yield evaluation was done at 12 months after planting. Significant interaction was obtained between varieties and time of planting for the number of roots harvested per plot. TMS 0581 recorded the highest average number of cassava root harvested 144.8 tubers in 2016. The number of tuber rot obtained per plot was significantly influenced by cassava varieties. TMS 0505 had 24.1 tuber rot per plot in 2015. This value amount to 13.2% loss in total number of storage roots formed and subsequent lowered yield (25.21 t/ ha) compared with other varieties. Similarly, higher percentage of rotten roots (10.3%) per plot was obtained for TMS 0505 in 2016. However, the root rot was only significantly lower than root yield of TMS 0581 that recorded 53.09 t/ha. The effect of time of planting was only significant for 2015 planting season. The four varieties evaluated exhibited high yield capacity under the production research plot. cassava yield, tuber rots, time of planting, cassava varieties