Evaluation of maize genotypes under irrigated and heat stress ecologies.

Abstract

Maize is cultivated in diverse agro climatic conditions of the world and it is third most important crop after rice and wheat. Genotype × environment interaction always an important role in production of any crop and maize requires optimum temperature(10-330C) for its growth and development. On the other side, increasing temperature impairs growth and development of maize plant. This study was conducted to evaluate 18 genotypes under optimum and heat stress conditions at Ludhiana in kharif and spring, 2019 to assess their performance under differential environments. Material was planted in two replications in RBD experimental design. For heat stress conditions, sowing was delayed and planting was done on 15th of March to expose the crop to high temperature during flowering stage. Temperature during the flowering period varied between 37-450C and no significant rainfall was recorded. High temperature causes reduction in grain setting and eventually grain yield decreases. Some of the genotypes showed good performance under both the environments viz. ZH 1799, ZH 17165, ZH 17153, ZH 16135 and ZH 191078 by showing least yield reduction and stable grain yield even under stressed conditions. Whereas, some genotypes i.e. ZH 191081, ZH 1783, ZH 16162, ZH 16418 and ZH 17123 showed high reduction in yield. G × E interaction plays a vital role in differential expression of genotypes. Best performing lines can further be evaluated under more diverse ecologies over the years. The lines which were best across the environments can be used as donors in development of hybrids for high temperature tolerance under a suitable environment or as testers in assessing the performance.