Evaluation of Groundnut Mini Core to Identify Sources of Tolerance to End of Season Drought in the Sahel, Niger

Abstract

Groundnut (Arachis hypogaea L.) productivity is very low in the Sahel mainly because of drought caused by low and erratic rainfall. End-of-season drought is the most important factor limiting groundnut production in the Sahel. Identification of genotypes that have a greater ability to use limited available water is important to enhance productivity of the crop. Objective: The study was conducted to identify tolerant groundnut genotypes to end of season drought. Methodology: About 100 mini core entries were evaluated for chlorophyll content and pod yield under well-watered and drought stress conditions. Soil plant analysis development chlorophyll meter readings have been suggested as a surrogate way to select for drought tolerance in groundnut. Drought tolerance indices were calculated for chlorophyll content at 45, 60 and 90 days after sowing. The experimental design was balanced α-lattice design replicated two times. Data collected were analyzed with GENSTAT software version 12.0. and LSD at 5% was used. Results: Highly significant differences were observed among the genotypes for all the traits. The effect of the two water regimes were significant for all traits measured. All the entries showed significant (p<0.01) differences for chlorophyll content at 45, 60 and 90 days after sowing, in both water regimes. The overall means under drought stress conditions were 41.16, 47.78 and 45.9, respectively at 45, 60 and 90 days after sowing. These ratings were higher than the overall means under irrigated condition (39.66, 47.77 and 41.75, respectively). Drought tolerance indices ranged from 0.51-1.76 for pod yield and from 0.91-1.13 for chlorophyll content at 60 days after sowing. ICG6703, ICGV-SM99511, Tainan-9, ICG11249 and ICGV-IS01820 were the best drought tolerant genotypes identified in this study. Conclusion: The varieties Tainan-9, ICG11249 and ICGV-IS 01820 performed well under both conditions. The varieties Tainan-9, ICG11249 and ICGV-IS01820 showed least pod yield difference between both water regimes can be used by farmers in the short term as drought tolerant varieties or be used as parental lines to develop new groundnut drought tolerant varieties.