Heavy application of flower fertilizer during the sesame flowering period promotes high yields

Sesame grows most rapidly when it enters the flowering and capsule-setting stage. At this time, vegetative growth and reproductive growth proceed simultaneously, and it is also the peak period of fertilizer demand. The nutrients absorbed during this period account for 70%-80% of the entire growth period. Practice has shown that topdressing with flower fertilizer can increase yields by more than 30%. For flower fertilizer, chemical fertilizers are more convenient to apply, but decomposed cake fertilizer, manure, barnyard manure, etc. can also be used. When drilling in rows, a furrow should be opened between the rows for banding or spot application, applied into the soil layer about 10 cm deep to facilitate root absorption, then covered with soil after application, and weeds in the field removed. In the case of broadcasting, except that decomposed cake fertilizer or granular urea can be mixed with soil and broadcast, followed immediately by intertillage and loosening of the soil to cover the fertilizer, all other chemical fertilizers should be applied by opening holes and spot application. Broadcasting must be avoided to prevent fertilizer from adhering to the fine hairs on sesame leaves and causing seedling burn. In dry weather, irrigation after application is needed to give full play to the fertilizer effect. Generally, 5-8 kg of urea is used per mu.

In addition, from the beginning of flowering to the full flowering stage of sesame, foliar fertilizer spraying should also be carried out. The sesame stem is upright, the leaves are broad, and the stems, leaves, and flowers are densely covered with fine hairs, giving a strong ability to receive and retain fertilizer solution. Foliar spraying has low cost, high work efficiency, and a good effect of supplying water and fertilizer together. Spraying fertilizer can also be combined with pest and disease control. According to experiments, spraying potassium dihydrogen phosphate solution twice during the flowering period increased the 1000-grain weight by an average of 0.09 grams, with a yield increase rate of 19%. Spraying twice means spraying once at the early flowering stage and spraying a second time after an interval of 5-7 days. Generally, 200-250 grams of potassium dihydrogen phosphate is used per mu, diluted with 50-62.5 kg of water, and sprayed on both the front and back of the leaves. This should be done on cloudy days or in the evening on sunny days to avoid interference from high temperatures and dry hot winds during spraying, reduce evaporation of the nutrient solution, and better facilitate the leaves' absorption of nutrients.