GENETIC VARIABILITY STUDIES AMONG OKRA (ABELMOSCHUS ESCULENTUS (L.) MOENCH) VARIETIES GROWN IN SUDAN SAVANNAH AGRO-ECOLOGICAL ZONE OF NIGERIA

Abstract

The research was carried out at the teaching and research farm Gaya, Kano University of science and technology Wudil, Kano State and Kiyawa, Jigawa State Nigeria, during 2019/2020 dry season using irrigation to evaluate the genetic variability among some okra varieties grown in Sudan savannah agro-ecological zone of Nigeria. The experiments were laid out in a randomized complete block design (RCBD) with four (4) replications. The treatments consisted of eight Okra varieties (G207, LD88-1, NHAE47-4, Kunchin Biri, Clemson, ‘Yar yamidi, G989, and NHBIA-13). Data obtained were subjected to analysis of variance (ANOVA) as described by Snedecor and Cochran (1967), and mean were separated by (SNK) at 5% level of significance using the Statistical Application for the Sciences software (SAS, 2003). Analysis of variance indicated that 9 varieties of okra under study differ significantly for 11 quantitative characters such days to 50% germination, days to 50% flowering, days ta first harvest, duration of fruiting, mean pod diameter, mean pod length, number of leaves, number of branches, plant canopy, number of pods per plant, and pod yield per plant in combined analysis across two locations. Taking a simultaneous investigation of the three important genetic parameters together such as genotypic co-efficient of variation, heritability and predicted genetic advance at a glance at phenotypic and genotypic level, characters like days to 50% germination, days to 50% flowering, days to first harvest, duration of fruiting, mean pod diameter, mean pod length, number of leaves at harvest and number of pods per plant showed higher values for heritability and genetic advanced. The experiments were laid out in a Randomized Complete Block Design (RCBD) with four (4) replications. The two experimental sites were ploughed and harrowed to obtain favourable condition for crop establishment. The entire lands were razed and assemble into seed beds; water channels were also assembled to facilitate good and free water movement and uniform distribution on the plots. The experimental fields were harrow to obtain good tilt and seed beds were made by using small hoes and furrow irrigation to create a favourable condition for plant establishment. The gross field size was 40m x 11m (440m 2 ), while the net plot size and the plot size were 2m x 2m (4m 2 ). A distance of 0.5m and 1m was left between plots and replication, respectively. The seeds were sown 30 cm intra and 75 cm inter row spacing respectively. Two seeds were sown on each spot to acquire adequate germination. The crops were irrigated immediately after planting, and subsequently irrigation was done at 3 – 4 days interval. The 15:15:15 NPK fertilizer at the rate of 60 kg N/ha was applied at two split application, three weeks after planting and at flowering stages. Hand hoeing was used to control weeds at 3 and 6 WAS and occasional hand pulling was done to ensure weed free plots and to avoid competition for soil moisture, nutrients, light and gases (oxygen and carbon dioxide). Pods were harvested at every three days interval after first picking. Pods were harvested through hand picking at tender and marketable stage. Data was collected for eleven characters from five centered plants tagged. The eleven characters studied include days to 50% germination, days to 50% flowering, days to first harvest, duration of fruiting, plant canopy (cm), number of leaves, number of branches, number of pods per plant, pod length (cm), pod diameter (cm), and pod yield/ plant (kg/ha). Combined analysis (ANOVA) across the two locations was done with the use of SAS statistical package. However, genotypic variance, phenotypic