Abstract:

The aim is to screen out high-yield, stable and tolerant to late sowing wheat varieties. By comparing the differences in agronomic traits and yield of 17 wheat varieties, the study aims to provide a basis and theoretical support for the selection of varieties for high yield and stable yield of wheat in late sowing areas. Using CJ580 and other 16 wheat varieties as test materials, a single-factor random block design was employed to measure the three key yield components at maturity, and convert the grain yield according to 13% moisture content. The number of tillers per plant and the earing rate were measured at various growth stages. At maturity, 20 representative plants were randomly selected to measure plant height and ear length. The main diseases that are likely to occur under late-sowing conditions were monitored, and their severity was assessed visually during the peak disease period. Data were analyzed using SPSS and the LSD method. The results showed that there were significant differences in the tiller dynamics of different varieties at various growth stages: YF19 had the highest number of tillers during the winter survival stage, YF19, ZM18, and YM23 tied for first place during the green-up stage, and YM1 reached its peak (1008×10⁴/hm²) during the jointing stage. CJ580, YM43, and YM36 performed optimally during the earing and milk stages, with the tiller-to-earing rate ranging from 44.64% to 49.79%. In terms of plant height and ear length, YM1, YM34, and YM46 stood out (plant height> 66 cm, ear length> 8 cm), while ZM23 and YM30 were significantly lower. Disease monitoring showed that all varieties had not experienced Fusarium head blight, rust, or lodging, with only a few showing mild powdery mildew. The study found that late sowing generally led to reduced yields, shortened growth periods to 200 days, and a general decrease in plant height. Outstanding varieties regulate the three key factors of yield through a differentiated compensation mechanism. These factors include high ear numbers (YM43), balanced agronomic traits (YM1), ear-to-grain number advantage (YM34), and outstanding thousand-grain weight (YM46), all achieving stable yields above 6500 kg/hm². This study provides practical guidance for variety screening under extreme climates, but the conclusions need to be further validated through multi-year and multi-regional trials. In summary, ‘YANGMAI 43’, ‘YANMAI 1’, ‘YANGMAI 34’, and ‘YANGMAI 46’ are suitable for initial promotion in Hanjiang District, Yangzhou under extreme climates and late sowing conditions as late-sowing-resistant and stable varieties.

Key words: winter wheat, late sowing, variety, phenotypic traits, extreme climate