Agro-meteorological indices in relation to cotton yield in a Mediterranean environment

Abstract

The effect of climate change is an important factor that significantly affects flower and boll production and consequently cotton yield. Field experiment as conducted to study the effect of weather parameters on cotton yield and yield components under varying environmental conditions. Two cotton varieties, ‘Elsa’ and ‘Med 10-19’, were studied over three years (2020, 2021 and 2022) at three different locations (Kopaida, Elatia and Farsala) in central Greece using a randomised complete block design with three replications. Daily meteorological data were collected and used to calculate several agro-meteorological indices, including heat units (GDD), heliothermal units (HTU), heat use efficiency (HUE) and heliothermal use efficiency (HTUE). The combined analysis of variance showed significant effects for the environment and year on the agro-meteorological indices and yield traits, contributing about 61% of the total variation in heat use efficiency, 62% in heliothermal use efficiency and 56% in seed yield, while variety accounted for 32% of the total variation in seed yield. Analysis of the results between varieties showed that Elsa consistently outperformed ‘Med 10-19’ in all environments and years. This was evidenced by ‘Elsa’ having the highest values for heat use efficiency, heliothermal use efficiency and yield traits. Application of agro-meteorological indices provides useful information related to the effect of temperature and sunshine hours on crop phenology, seed yield and heat energy consumption in cotton cultivars.

Keywords

• Gossypium hirsutum
• growing degree days
• heat use efficiency
• heliothermal use efficiency
• seed cotton yield
• yield components