There are many kinds of weeds in watermelon fields, and the main hazards are 阔, 苋, 凹 苋, 苋, 马, wild watermelon seedlings, iron leeks, Xanthium and other broad-leaved weeds and crabgrass, foxtail, cattle Weed grass, teff grass and other grass weeds. There are two peak periods in the occurrence of weeds in watermelon fields. The first peak period is before and after the watermelon seedlings are unearthed. The weeds in this period account for about 60% of the total number of weeds in the whole growth period of watermelon. The second peak period is about 70 cm in length when the watermelon vines are about 70 cm long. 30%. The weeds in the watermelon field are mostly large in roots, adaptable, fast-growing, widely spread, and long-lived. If not prevented in time, it is easy to compete with watermelon for sun, fertilizer and pests. According to the China Pesticide Network , weeds in watermelon fields should be comprehensively controlled. It is necessary to pay attention to the comprehensive prevention and control of diseases, insects and grasses, as well as comprehensive measures such as agricultural control, weed quarantine, machinery, chemistry and physics. Different areas, different plots, and different years should have different prevention and control contents and prevention methods.
Steps/methods preventive measures. Strict quarantine system to limit the invasion of dangerous weeds in foreign countries and in infected areas. Remove weeds from the fields and fields to prevent weed seeds from spreading and continue to breed. The farmer's fertilizer is fully decomposed and the weed seeds mixed in are killed. Clean the irrigation water and reduce the grass into the farmland. Weeding measures. Reasonable rotation, blocking weeds from germination or promoting their germination, eliminating weeds. Soil cultivation measures such as ploughing, hoeing and cultivating are the basic methods for eliminating weeds for a long time, and are the main methods in current agricultural production. Some weeds can also be removed by biological methods such as animals, insects, and germs. It is also possible to use mulching techniques to control weeds in the field.
Chemical weeding. Chemical weeding is the use of herbicides to control harmful weeds. In order to protect crops, it is necessary to coordinate the relationship between herbicides---weeds-------the environment. Watermelon is very sensitive to the herbicide reaction. Therefore, according to the nature, characteristics, weed traits, types and different environmental conditions of the herbicide, the pharmacy and design method should be used reasonably. After experimenting, demonstrating and gaining experience, it should be gradually promoted.
Precautions must strictly limit the invasion of dangerous weeds in foreign and infected areas. Otherwise, it is difficult to have effective herbicides.
The utility model discloses a Kitchen Shower head that is convenient to switch the water outlet mode, has a compact structure, and is easy to use and a kitchen faucet using the kitchen shower head. The shower head includes a shower body and a shower head provided with a spray water outlet and a V-shaped water outlet. , The shower head is provided with a water separator, and the water separator is provided with an annular flow channel and an inner flow channel respectively connected to the spray water outlet body and the V-shaped water outlet body, and the lower end of the outer wall of the water separator is upwardly circular A plurality of water inlet holes connected to the annular flow channel are provided, and a first sealing ring is provided on the lower side of the water inlet hole; the water outlet end of the shower body is connected with a converter, and the converter is provided with a communicating In the water diversion cavity at the water outlet end of the shower body, the lower end of the water diversion device is installed in the water diversion cavity and can move up and down, and the upper end of the inner wall of the water diversion cavity is provided with a matching first sealing ring
Kitchen Pull Shower,Kitchen Pull Shower Head,Stainless Steel Shower Head,Rotating Wash Basin Shower
Yuyao Zelin Sanitary Ware Co., Ltd , https://www.kitchen-sinkfaucet.com