Drought adaptation level of maize genotypes based on leaf rolling, temperature, relative moisture content, and grain yield parameters

Abstract

The adaptation level among maize genotypes under drought stress is strongly affected by morphology and physiology aspects. To assess the adaptation level of maize hybrids to drought weight, an experiment was conducted in the dry season of 2016 (June to September) at Maros Experimental Station. A total of 70 maize hybrids candidates were evaluated under drought stress at generative (flowering stage) until physiological maturity. The results indicated that leaf rolling scores were negatively correlated with grain yield under drought stress conditions. The hybrid 26/B11209 and P 31 that experienced early leaf moving and a higher leaf rolling score ranged from 4.3, and 3.9 had grain yield of only 1.3 t/ha and 1.2 t/ha respectively, lower compared to the hybrid 34/Mal 03 and Bisi 18 that experienced a delayed leaf rolling and lower leaf rolling score (<2.5) with yields of 4.3 t/ha and 3.9 t/ha respectively. The hybrids 34/Mal 03 and Bisi18 had mechanisms to reduce the area of leaves affected by radiation and maintain relatively higher leaf moisture content compared to hybrids 26 / B11209 and P 31. Leaf relative moisture content of hybrid maize 34/Mal 03 and Bisi 18 were higher viz., 79.9% and 78.7% respectively and lower leaf temperatures (39.4-39.8 °C) as compared to hybrids 26 / B11209 and P 31. The effective score assessment time of leaf rolling of the hybrid genotypes was when the whole hybrid genotypes experienced leaf rolling with ±50% genotype had leaf rolling scored 2 and ±50% of other genotypes scored 3.