Early Maturing Wheat Genotypes to Cope with Climate Changes

A field experiment was conducted to study the effect of climate changes on earliness and yield characteristics of bread wheat at Sakha Agricultural Research Station, Kafrelsheikh, Egypt during 2017/2018 and 2018/2019 seasons. Climate change represented by four sowing dates with one month interval starting from 5th November to 5th February. The results showed that the first and second sowing dates recorded maximum values for all studied traits while, the fourth sowing date was the least one. The highest values for grain yield were recorded for Lines 1, 6 and 4. Interaction effects showed that the three Lines 1, 6 and 4 produced the highest grain yield under the four sowing dates with superiority of Line 1. Stability analysis showed that Lines 1, 4 and 6 exceeded the average grain yield. Generally, most early-maturing genotypes had low heat susceptibility index (HSI) under late sowing. The studied genotypes can be classified into two groups. First group, climate change tolerant(wide adapted and grain yield stable across the tested environments) consisted of the early maturing Lines 1 and 4 where they recorded low HSI under early and late sowing. Second group, climate changes sensitive (tolerant to early sowing but sensitive to late sowing and vice versa) where it can be classified based on their HSI estimates to two subgroups. Subgroup one, tolerant to early sowing but sensitive to late sowing, include the latest genotype Misr2. Subgroup two, sensitive to early sowing but it is tolerant to late sowing; include the relatively early maturing Line6