Assessment of Selected Landrace and Improved Groundnut (Arachis hypogaea L.) Genotypes under Stressed and Non-stressed Conditions

Abstract

Drought is one of the most essential and critical abiotic restraints to groundnut production and yields in the Northern Region of Ghana. A field experiment was conducted to assess selected landrace and improved groundnut genotypes for agronomic performance in the 2017 and 2018 minor seasons. Groundnut genotypes were treated under normal irrigation (W/W) and water-stressed (W/S) conditions. A Randomized Completely Block Design (RCBD) with four replications was adopted. Total experimental area was 23.4m x 2.4 m with a planting distance of 40 cm x 20 cm for both environments. Data collected include; days to 50% emergence and flowering, plant height at maturity (cm), growth appearance, days to maturity, number of pods/plot, number of seeds/plot, pod weight (g), seed weight (g), fresh and dry biomass weights (g), SPAD chlorophyll meter reading at 60 and 80 days after planting, harvest index (HI) and drought tolerance index (DTI). The data were subjected to analysis of variance (ANOVA) using GenStat, version 12.0, Exploratory Analysis, descriptive Statistics (mean comparison of plant characteristics by varieties at 5% level using Tukey’s groups) was conducted; Correlation Analysis and Multivariate Analyses were performed using the Wilk’s Lambda to test for significant difference at 5% and 1% levels respectively. Means were separated using S.E.D. of means at 95% confidence level. Results from the growth features indicated a higher percentage of the groundnut varieties sprouted earlier under well-watered conditions. There was no significant difference among the groundnuts regarding the numbers of days to flowering. The groundnuts took approximately 104 days after planting to mature under both water conditions. Chlorophyll content and distribution in the groundnut leaves was high the well-watered plants. The chlorophyll content among the groundnut crops showed no significant difference between the chlorophyll content at 60-days after planting and 80-days after planting under the water-stressed condition. However, chlorophyll content of leaves at the 60-days after planting was 2.94 lower than that under 80 days after planting. Maturity and flowering (0.768), as well as plant height and seed yield (0.501) were highly significantly and highly positively correlated. The seed characteristics were also highly, significantly and positively correlated with the pod characteristics of the crop. The biomass measure also correlated with the pod and seed traits. Groundnuts genotypes under well-watered environment generally performed better in terms of yield than those under water-stressed environment.