Key Fertilization Techniques for Summer Sesame in the Mid-to-Late Growth Stage

For high-yield cultivation of summer sesame, fertilization should include heavy and shallow application of base fertilizer, a moderate amount of seed fertilizer, heavy application of flower bud fertilizer, and supplemental spraying of phosphorus and potassium fertilizers; organic fertilizer should be the main type, combined with phosphorus and potassium fertilizers, while chemical fertilizer use should be minimized as much as possible to improve sesame quality. To produce every 100 kg of sesame, the fertilizer requirement is: nitrogen fertilizer 6.24-8.13 kg, phosphorus fertilizer 2.19-3.28 kg, potassium fertilizer 6.24-10.19 kg.

However, in summer sesame cultivation in our province, most farmers do not apply base fertilizer, and for topdressing they only apply urea or a small amount of compound fertilizer. Unreasonable fertilizer application seriously affects the realization of sesame's yield-increasing potential.

At present, summer sesame in various areas of our province has entered the mid-growth stage, and fertilizer management in the mid-to-late stage must be carried out promptly to achieve increased yield and income.

Supplemental base fertilizer topdressing: For fields where no base fertilizer has been applied, topdressing should be carried out promptly to prevent nutrient deficiency. For high-yield fields, apply 10 kg of high-quality potassium sulfate compound fertilizer per mu, shallowly buried 4-6 cm deep; for medium- and low-yield fields, apply 10 kg of high-quality potassium sulfate compound fertilizer per mu, plus 5 kg of urea.

Heavy application of flower bud fertilizer: For fields where base fertilizer has already been applied, flower bud fertilizer should be applied heavily. For single-stem sesame, apply flower bud fertilizer from the bud emergence stage to the early flowering stage; for poor soil fertility or weak growth, it should be applied appropriately earlier; for branching sesame, topdressing when branches appear is preferable. Generally, apply 5-10 kg of urea per mu, plus 5 kg of high-quality potassium sulfate compound fertilizer, or apply 10-15 kg of high-quality potassium sulfate compound fertilizer per mu.

Supplemental spraying of phosphorus and potassium fertilizers: At the early flowering stage of summer sesame, use 50 kg of 0.3%-0.4% potassium dihydrogen phosphate solution per mu, sprayed evenly once every 5-6 days, for 2-3 consecutive sprays. At the same time, 50 kg of borax, ammonium molybdate solution, or zinc sulfate solution can also be sprayed at intervals per mu, which can increase yield by more than 10% per mu. Generally, the spraying concentration is 0.2% for borax, 0.05% for ammonium molybdate, and 0.2% for zinc sulfate.