Weed control in summer sesame fields: master three stages and use the right herbicides to prevent weed infestation

The seedling stage of summer sesame happens to coincide with the hot, rainy season. At this time, sesame has few roots and weak growth, while weeds in the field emerge quickly, are dense, and grow vigorously, easily shading the sesame seedlings and forming a weed infestation. To protect the seedlings, you must seize the different stages and choose the corresponding herbicides for chemical control. The following three steps cannot be neglected at any one of them.

Step one: after sowing but before emergence, soil-closing weed control

After sesame sowing is finished, while the weeds have not yet emerged, first carry out a soil-closing treatment. Use 100 milliliters of 50% acetochlor emulsifiable concentrate per mu, or 200 milliliters of Dual (72% metolachlor emulsifiable concentrate), add 50 kilograms of water, and spray evenly. This application can effectively control many annual grass weeds such as foxtail, crabgrass, shortawn foxtail, and goosegrass, and also has a certain effect on many broadleaf weeds propagated by small seeds. After spraying, pay attention to keeping the soil moist, and do not cultivate or loosen the soil within 50 days, so as not to damage the herbicide layer and affect the closing effect.

Step two: skillfully use paraquat before emergence to clear weeds that have already emerged

Weeds in summer sesame fields generally emerge 3-10 days earlier than sesame and grow aggressively. You can make full use of the period before sesame emergence to use paraquat against weeds that have already emerged, using 200 milliliters of 20% paraquat aqueous solution per mu, add 40 kilograms of water, and spray. Paraquat is a contact-type non-selective herbicide. The spray solution can be quickly absorbed by plant leaves, causing photosynthesis and chlorophyll synthesis to stop rapidly, and the leaves begin to change color 2-3 hours after the chemical contacts them. However, it cannot translocate within the plant, so it can only damage the parts exposed to the chemical. Even more convenient is that once this chemical contacts the soil, it is inactivated and loses effectiveness, with no residue, and has no effect on sesame emergence.

Step three: after emergence, choose the correct selective herbicide

After sesame emerges, when the weeds grow to the 2-3 leaf stage, use 70-100 milliliters of Jinghecaoke (5% quizalofop-p-ethyl emulsifiable concentrate) per mu, or 50 milliliters of Jingwenshade (15% fluazifop-p-butyl emulsifiable concentrate), add 40 kilograms of water, and spray. 4-5 days after application, the weeds will show poisoning symptoms such as yellowing of the heart leaves and browning of the internodes, and after 7-8 days the entire plant dies. This type of chemical mainly controls annual grass weeds such as wild oat, crabgrass, goosegrass, shortawn foxtail, foxtail, and Chinese sprangletop. It is highly targeted and safe for sesame.

Overall, chemical weed control in summer sesame requires distinguishing the stages: close the soil after sowing but before emergence, clear weeds that have already emerged before emergence, and specifically remove grass weeds after emergence. When the three steps are coordinated and applied properly, the weed infestation problem can basically be controlled, and the sesame seedlings will naturally grow strong.