Iris disease prevention methods: General soil treatment : The soil should be free of pathogens. The following treatments can be carried out (1) for new soil or for full rotation in the field. (2) Strengthen management to ensure good growth conditions. For soil treatment, once a year. The main purpose is to disinfect the soil by steam sterilization, soaking or using chemical methods. Which method is used depends on the temperature, duration of use and energy. Steam disinfection : disinfect the soil with a depth of 25 to 30 cm with steam at 80 ° C for at least 1 hour. The low pressure steam is better than the high pressure steam. Vapor disinfection can prevent other diseases besides Pythium. Steam sterilization is supplemented by the application of special fungicides to better sterilization. However, for silt with lower pH, steam sterilization can cause manganese damage. The use of steam for short-term disinfection, and the addition of appropriate amount of lime in the soil to adjust the pH value, the manganese content can be limited to a certain range. Soaking : This method is used to disinfect the soil in the greenhouse. The first step is to plant two-color sorghum crops in May. The second step is to plow the soil layer to 20cm deep in about mid-June when the plant is about 50cm high. Then 100 kg of calcium nitrate was applied per 1000 m2 of soil. At the end of July, the soil surface was made into a crucible with a width of 60 to 70 cm, and the film was filled with water. After 2 to 3 weeks, the soil was treated with a rotary tiller and the pH and conductance values ​​were checked. Chemical treatment of soil : If conditions permit, disinfectants and chemicals can be used to disinfect the soil. In this way, it should be carried out at a soil temperature of not less than 10 to 12 ° C, followed by covering the film. The film was removed after 3 days in warm weather (7-10 days in shady weather). Other methods of soil treatment : Since Pythium is highly regenerative, it is not enough to perform a normal treatment once a year. In order to control the growth of fungi, a fungicide is used for anti-infestation treatment before each planting. In order to spread evenly, the wettable powder is mixed with sand, and then spread by hand, or heated water sprayed with a coarse spray nozzle, the effect can be 15 to 20 cm below the soil surface. It is necessary to mix the fungicide with the soil by hand or using a rotary tiller. Bulb processing : In the production of iris cut flowers, the bulbs must be dipped in the fungicide before planting. Different concentrations of fungicides determine different treatment methods. Ball rot disease : It seriously harms the bulb, the surface can not be seen or very late to appear. The underground roots grow little or no roots. Plants that are lightly damaged are low and curved (see Fusarium). From the root crown, the tissue turns black or blue-brown, and is covered with spores. Unlike Fusarium infection, plants infected with root rot do not contract inward, so healthy plants and susceptible plants are not easily distinguishable in appearance. The disease is not easy to spread and will not contaminate the soil for a long time. Pipe Fitting,Butt Welding Tee,Butt Welding Crosses,Stub Ends ZHITONG PIPE VALVE TECHNOLOGY CO.,LTD , https://www.ztpipevalve.com