First, the occurrence of weeds in watermelon fields. There are many kinds of weeds in watermelon field, and the main damages are scorpion, scorpion, acerola, amaranthus retroflexus, purslane, wild watermelon seedlings, iron leeks, cocklebur broad-leaved weeds, and crabgrass, setaria, and sorghum. Grass, goosegrass, teff grass and other grass weeds. The occurrence of weeds in watermelon field has two peak periods. The first peak period is the excavation of watermelon melon seedlings, and weeds are also excavated in large numbers. The weeds in this period account for 60% of the total number of weeds in the whole growth period of watermelon. The second peak is when the watermelon grows about 70 centimeters. Second, herbicides and weeding period. Herbicides are divided into non-selective and selective types, the former can effectively control all kinds of weeds, and the latter can selectively control a certain kind or a certain type of weeds. At the peak of the first weed occurrence, the herbicides such as grafloxacin, herbicidal ether, chlorfenapyr, amphophophos, herbicide, and herbicide may be applied to the soil surface before sowing. At the peak of the weed occurrence, we should use the herbicides that can ensure the safety of watermelons, such as grass cover, stable killing, and fine grass weeds. These herbicides can be sprayed during the 2-5 leaf stage of grassy weeds and can be controlled. Weeds are safe on watermelon seedlings. Third, the use of herbicide technology 1, non-selective herbicides: If this type of herbicide is used improperly, it is easy to cause damage to watermelon seedlings, suitable for watermelon before sowing after sowing. Such as grass grazing: can be used before sowing after seeding, mu 50% CWP WP 150-200 g surface spray, control of annual weeds, herbicidal ether: 25% per acre herbicidal WP 500-750 Grams, sprayed on the surface of the watermelon before sowing after emergence, uniform application of spray, control of annual weeds; grass killing: before the emergence of watermelon, per acre with 80% chlorfenapyr 150-200 grams of surface spray. 2, select herbicides. This type of herbicide is suitable for use during the growing period of the watermelon and will not cause phytotoxicity to the watermelon. For example, Gaoxoneng can control annual and a few perennial grasses weeds, weeds in grass, 2-5 leaf phase, control annual valerian, use 12.5% â€‹â€‹per acre with 65 ml of emulsifiable oil, leaf and leaf spray treatment , to prevent the use of perennial grasses to double the dosage. Steady and stable kill: Effective against annual and perennial grasses, but not against broad-leaved weeds, in the 2-5 leaf stage of grass, with 35% or 15% of fine stable per mu. Emulsifiable oil 70-130 ml, spraying stems and leaves. Fine grass gram: spraying stems and leaves during the 2-5 leaf stage of grass weeds, the efficacy is fast, and the effect is good. To control annual weeds, weeds use 10% of refined grasshopper grams of 65-100 ml of emulsifiable concentrate, and prevent perennial weeds to use 150-250 grams of 10% EC per acre. The rain after 3 hours of spraying did not affect the efficacy.
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