Effects of Different Sowing Dates on Dry Matter and Yield of Three Edible Sunflower Cultivars in the Ta e Basin

In order to fully tap into the production potential of sunflowers in Ta’ e Basin, the experimental design of sowing date and variety two-factor split-plot was adopted, three replicates, the main zone was the sowing period, and three levels were set: T1（May 3）,T2（May 10） and T3（May 17）, the sub-zone was the variety, and the three varieties were tested: Sanrui 3（SR3）, Sanrui 373（SR373）, SH363. And the field performance of the three edible sunflower plants in dry matter accumulation, distribution characteristics and yield were analyzed, and the commonality of the three varieties was analyzed, so as to fully explore the response to the sowing period and its potential for yield increase.The results showed that, the sowing date had a significant effect on the dry matter accumulation of various organs in the aboveground parts of the three sunflower cultivars at different growth stages. At the seedling emergence, budding stage, flowering stage and maturity stage, the total amount of dry matter accumulation above ground and the accumulation of dry matter in each organ of the three sunflower varieties were the highest on May 10, indicating that early or late sowing was conducive to the increase of dry matter quality. The dry matter accumulation of aboveground organs in different varieties showed that SR3 was significantly higher than that of the other two varieties. The maximum dry matter accumulation rate(v_max) of the aboveground part on May 10 was the largest, which was 50.00% and 55.10% higher than that on May 3 and May 17, respectively, and extended the rapid accumulation time of dry matter by 6.3 days and 7.3 days compared with the other two sowing periods. On May 10, the sowing date was the best in the seed number of single discs, single grain weight, setting rate, seed kernel rate and yield, all of which were significantly higher than those of other treatments, and the yield composition and disc diameter of sunflower showed a significant positive correlation between single disc weight and yield, the correlation coefficient was 0.997 and 0.996. And the seed kernel rate, seed number of single disc and yield were positively correlated, the correlation coefficients were 0.962, 0.949 and 0.928, respectively. Combined with the sowing date and yield composition, sunflower planting in the appropriate sowing period can give full play to the plant yield potential and achieve the effect of increasing yield.Comprehensive experiments show that the planting and sowing treatment of different sunflower varieties in the Taege Basin is best on May 10, which is conducive to mobilizing plant growth factors, prolonging the rapid accumulation time of dry matter, promoting dry matter accumulation and distribution, and giving greater play to its yield potential, and the comprehensive performance of the variety is that SR3 is better than the other two varieties.