EVALUATION OF INSECT PEST TOLERANCE AND OIL QUALITY IN ETHYL METHANE SULFONATE (EMS) EXPOSED GROUNDNUT (ARACHIS HYPOGAEA L.)

Abstract

Groundnut (Arachis hypogaea L.) is a multipurpose legume crop widely cultivated in sub- Saharan Africa. However, there are several species of groundnut field insect pest which are responsible for substantial yield losses. Hence, the study aimed at evaluating EMS induced groundnut genotypes for insect pest tolerance and oil quality. The seeds of four (4) groundnut genotypes, SAMNUT 26, SAMNUT 25, SAMNUT 24 and ICG 4412 collected from the institute for Agricultural Research (IAR), Samaru, Zaria, Kaduna state were treated with various concentrations of EMS Viz (0.0 % (control), 0.1 %, 0.2 %, 0.3 % and 0.4 %) for 6 hours and sown in well labeled planting bags along side with their respective controls. The experimental bags were laid out in Complete Randomized Design (CRD) with three (3) replicates each. Data were collected on Agromorphological parameters and insect infestation rate of each genotype. Seeds from the genotypes were further characterised for oil yield and oil attributed parameters at NCRI, Badegi. The result of plant height at maturity showed that the tallest plant for SAMNUT 25 and SAMNUT 26 was recorded in 0.30 % concentration with the value of 44.43 and 45.63 cm, respectively while for SANUT 24 and ICG4412 was obtained in 0.10 % with the value of 51.17 and 50.13 cm, respectively. With the exception of SAMNUT 24 in which the control had the least height (37.43 cm), the least height 39.90, 23.17 and 29.60 for SAMNUT 26, SAMNUT 25 and ICG4412 were recorded in 0.20 % EMS treated plants. Concentration 0.1 % of SAMNUT 24 had the highest number of leaves and leaf area among the genotypes with the value 426 leaves and 26.78 cm², respectively. Yield parameters assessment revealed that SAMNUT 24 had the highest average number of pod per plant (26.33 pods) and seed per plant (2.39 seeds) at 0.10 % and 0.20 % concentration, respectively. Highest weight of pod (2.08 g) and 100 seeds (54.34 g) were recorded at 0.30 % of SAMNUT 26 and at 0.10 % of SAMNUT 24, respectively. Significantly (p < 0.05) least weight of 100 seeds per plant was recorded at the control of ICG4412 with the value of 6.00 g. In terms of oil yield, 0.20 % treated seeds of SAMNUT 25 had the maximum oil yield (39.34 %) among the genotypes while 0.30 % treated seeds of ICG 4412 plants had the minimum of 21.78 %. Significant variations were observed in number of insects among the genotypes and concentrations at different weeks. Lower insect populations among the genotypes were observed at 14th weeks of evaluation, with different genotype having least insect infestation as different concentration. The positive changes in pod characteristics of SAMNUT 24 (0.1 % an 0.2 %, EMS treatments) could be exploited for increasing the productivity of groundnut and for further improvement of the crop.