On-farm assessment of agronomic performance of rainfed wheat cultivars under different tillage systems

Abstract

Evaluation of new cultivars for the agronomic performance under actual on-farm conditions is a highly recommended method for assessing the performance and stability of new cultivars in variable environments and under different management practices. The main purpose of this study was to evaluate the performance and agronomic characteristics of new wheat cultivars in on-farm conditions using different tillage systems to provide suggestions to help the improvement programs and increase the farmers' crop productivity from cropping systems and new cultivars. Seven wheat cultivars, including three bread wheat and four durum wheat cultivars, were evaluated under three tillage systems, including conventional tillage (CT), reduced tillage (RT), and no-tillage (NT) in farmers' fields conditions across two locations and three cropping seasons (2018–21). The results indicated that some of the traits were mainly explained by the genotype effect (thousand kernel weight, heading date and NDVI), while some others by the management practices (grain yield), some by the location (grain yield, spike density, heading date) and year (grain yield, TKW, NDVI, spike density, heading date) effects. Across years and locations, the highest productivity was recorded under CT (2603 kg/ha) followed by RT (2378 kg/ha) and NT (2295 kg/ha), indicating about 13% and 10% superiority production under CT compared with NT and RT, respectively. The wheat cultivars showed different responses to tillage systems, showing the performance of genotypes varied between tillage systems. The Shalan and Eminbey varieties did not interact with tillage systems, but other genotypes significantly differed in their adaptation to tillage systems. The highest mean yield was recorded for the Saji cultivar (durum wheat) under RT (2310 kg/ha), while the Shalan cultivar (bread wheat) performed well in NT (2058 kg/ha), and Saji, Imren, Zahab (durum wheat), and Rijaw and Paraw (bread wheat) had the highest yield under CT. According to GGE biplot analysis, the Shalan and Eminbey varieties had superior performance across on-farm trials, suggesting that they have a broad adaptation to diverse environments. The results identified genotypes with both specific and general adaptions to tillage systems in farmers' fields, that could be explored for increasing productivity and stability under rainfed conditions. Conservation agriculture principles must be incorporated into current wheat breeding program under CT system, to use wheat genetic diversity for conservation agriculture conditions to keep pace food insecurity.