Effect Heat Stress on Wheat Genotypes Productivity under Different Sowing Dates at Eastern Sudan

Abstract

Temperature plays a crucial role in determining the optimal sowing date. High temperatures during grain filling can lead to lower yields. While moisture levels also influence the optimal sowing date, with adequate moisture essential for healthy growth, wheat cultivars show significant variation in their response to sowing dates. The present investigation was carried out to determine superior cultivars under various sowing dates at the Eastern Sudan New Halfa conditions. A field experiment was carried out at New Halfa during the winter seasons 2017/018 and 2018/019 to study the effects of five sowing dates:20th Oct (S1), 25th Nov (S2), 30th Nov (S3), 15th Dec (S4) and 30th Dec (S5) on productivity of The three wheat cultivars: Nebta (v1), Bohain (v2) and Debera (v3).  The experiment was arranged in RCBD as split plot trail. All data were analyzing using Statistic (10). Means comparison was worked out using (DMRT) at 5% probability level. The results revealed that sowing dates and cultivars significantly affected phonological and yield attributes: number of spike/m2, number of spikelets/spike, 1000-grain weight, and grain yield (kg/ha). Generally, Debera (V3) recorded the latest days to heading and maturity. But Nebta cultivar (V1) gave the highest numbers of spike /m2 and the heaviest 1000- grain weight, while Bohian (V2) gave the highest number of spikelets /spike. The heaviest 1000- grain weight was recorded in first sowing date (S1). The normal sowing date (S3) maximized grain yield (4277.3 kg/ha) for V3 cultivar, while the lower yield (1266.7 kg/ha) was recorded when sowing V1 at first sowing date in the first season. Sowing V3 at the normal sowing date S3 in the New Halfa area is the best choice for getting a higher grain yield. Further research is needed to identify the most suitable sowing dates for different wheat cultivars and to develop strategies for improving yields under varying environmental conditions.