How to use herbicide in watermelon field?

How should herbicides be used in watermelon fields? Watermelon is one of the important cash crops in our county. In order to meet the needs of different periods, watermelon planting methods are also diverse, including direct seeding, transplanting, open-air cultivation, plastic film mulching, primary small arch shed, secondary small arch shed, medium shed and greenhouse. No matter open field or protected field, weeds in melon field are not convenient to be pulled out manually, and melon seedlings are delicate, so phytotoxicity is very easy to occur. How to select safe, efficient and high-quality pesticides and how to use herbicides correctly in watermelon fields with different planting methods have become important issues for plant protection workers. According to plant protection station field experiment situation union old state agriculture technology station Yang stationmaster experience introduction, now summarizes the experience as follows. 1. The occurrence law of weeds in watermelon field: There are many kinds of weeds in watermelon field. The weeds causing harm mainly include crabgrass, goosegrass, Setaria, barnyardgrass, Eragrostis and other grass weeds such as Chenopodium, Amaranthus, Stellaria, Bromus, Amaranthus, Amaranthus, Purslane, Amaranthus, Xanthium and other broad-leaved weeds. There are two peak periods of weed occurrence in watermelon field, the first peak period is when watermelon seedlings are unearthed and weeds are also unearthed in large quantities, at this time, the weeds emerging account for about 60% of the total number of weeds emerging in the whole growth period of watermelon, and the second peak period is when watermelon vines are about 70 cm long. 2. Herbicide types and weeding period: According to the different control periods of watermelon weeds, herbicides in watermelon fields can be divided into two categories: soil treatment and stem and leaf treatment. The former can effectively control most of the weeds in the field and eliminate the weeds in the bud. The latter can selectively control certain types of weeds during the weed growth period. In the first weed peak period, soil treatment agents such as napropamide, dimetriol and butralin were used to treat soil surface after sowing and before watermelon seedlings emerged. In the second weed occurrence peak period, selective herbicides such as chlorfenuron, quizalofop-methyl, etc., which are safe to watermelon, should be used. These herbicides should be sprayed at the 2~5 leaf stage of grass weeds. 1, soil treatment: there are many varieties of this kind of herbicide, if used improperly, it is easy to cause damage to watermelon seedlings, the author summarizes the field application as follows: 1.1 direct seeding field: ① direct seeding in the open air: after sowing, watermelon seedlings can be applied before the emergence of anachlor, Dahuili, Du Er, and other herbicides to treat the soil surface. Among them, napropamide and dahuili have higher requirements for soil moisture. If the soil is dry and the water spray is normal, the field reflection effect is poor. To use such pesticides, water consumption must be increased. These two pesticides are very safe to watermelon, and have good control effect on grass weeds, but have poor control effect on a small number of broadleaf grasses such as purslane and chenopodium. The dosage of the preparation is 120-180g per mu. Do not choose this herbicide in melon fields dominated by broadleaf weeds. Dur or kindur (metolachlor) has good control effect on watermelon weeds, and the current market dosage is large. However, in practical application, the dosage is slightly larger, and the phytotoxicity is obvious. The author has done repeated comparison, in the case of normal use, the blank control watermelon more or less than the use of medicine to grow vigorously. Phytotoxicity is the main factor affecting the application of these herbicides. It is suggested that farmers friends must not increase the dosage at will, and friends who have no experience in using it should use it carefully. ② Direct seeding in protected land: There are fewer and fewer watermelon cultivation in the open air in our county. The anti-season watermelon such as greenhouse, arch shed and plastic film develops rapidly. It is very difficult to weed artificially, while the moisture content of protected land is good, and herbicides are just applied. However, we should be extra cautious in the selection of varieties. In terms of dosage, no matter what kind of pesticide is used, the amount used shall be carefully calculated according to the actual use area (1 mu of land, about 0.5-0.6 mu of protected land area), and the dosage shall not be increased at will. ③ Plastic film cultivation: Napropamide, Dahuili, the effect is relatively good, can be applied. After watermelon sowing before the seedling application, because the moisture content under the film is better, can choose the recommended application of the low limit. In terms of safety and control effect, napropamide and dahuili were the best. 4. Greenhouse and arch shed cultivation: The screening test for many years showed that napropamide and dahuili were the most suitable soil treatment agents in greenhouse and arch shed watermelon field. Butralin, trifluralin, Shitianbu (pendimethalin), or kindol (metolachlor) cannot be used. Phytotoxicity often occurs in watermelon, and the lesson is profound. Demerol, trifluralin and Shitianbu all had backflow toxicity to watermelon. After watermelon is sown, if the herbicide is used, the liquid medicine sprayed on the surface of the soil evaporates due to the high temperature of the field microclimate, and water drops accompanied with the liquid medicine are formed on the film surface of the arch shed. If the water drops drop on the growth point, the growth point will be necrotic, and the water drops on the leaf surface will form spots, which is the so-called backflow phytotoxicity. Napropamide and dahuili have no backflow toxicity, are safe and efficient, and the dosage is controlled at about 150g/mu. 1.2 Watermelon transplanting field cultivation: watermelon transplanting field using herbicides, to master half a day or one day before transplanting soil treatment. The herbicide varieties selected by different planting methods are basically the same as those selected by the same planting methods in direct seeding fields. Demerol, Dur or Kindur (metolachlor), Trifluralin, and Shitianbu (pendimethalin) should not be sprayed directly on watermelon seedlings. Anachlor and dahuili can be used after transplanting under normal conditions, but if the dosage per unit area is high and the water is not timely, the growth of watermelon seedlings is easily inhibited. Farmers should be careful. 2. Stem and leaf treatment agent. The herbicide is suitable for watermelon growth period and will not cause phytotoxicity to watermelon. No effective pesticides were found to control broadleaf weeds in watermelon field, but more pesticides were found to control gramineous weeds. Common such as high-efficiency cover grass can, fine stability kill, fine grass grams and so on. High effective clover, can control annual and a few perennial grass weeds, grass weeds in the 2~5 leaf stage of the application. For annual grasses, spray 50-60 ml of 10.8% high-effect clopramide EC on stems and leaves per 667 m2; for perennial grasses, double the dose. The control effect of fenvalerate on annual and perennial grasses was good, but it had no effect on broadleaf weeds. At the 2~5 leaf stage of gramineous weeds, 70~ 130ml EC of 35% or 15% fenvalerate was sprayed on stems and leaves of 667 square meters. Quinclofop-g is sprayed on the stems and leaves of grass weeds at the 2~5 leaf stage, with fast efficacy and good effect. 60~ 80ml 8.8% EC was used per 667m2 to control annual weeds and 150~ 250g 8.8% EC was used to control perennial weeds. Rain 3 hours after spraying did not affect the efficacy. Watermelon overgrown weeds, not only compete for space, sunlight and fertilizer, affect the normal growth of watermelon, but also a variety of pests and diseases in the middle of the parasite, watermelon is the natural enemy. Now we have herbicide this weapon, we should be familiar with, master weeding technology, make good use of this weapon, make it for watermelon harvest production more sweet! Click to view more herbicide application techniques Click to view more pesticide application techniques Click to view more watermelon cultivation techniques