The prevention and control of diseases and insect pests in hot farming should be done well after a strong typhoon.

This year's 9th super typhoon "Weimasun" successively made landfall in Hainan, Guangdong and Guangxi from July 18 to 19, with a maximum wind of 17. The typhoon passed through the area with strong winds and torrential rain, causing serious damage to crops such as bananas, Lizhi, mangoes and sisal. The post-disaster high temperature weather can easily induce the outbreak and spread of a variety of diseases and insect pests, such as banana Fusarium wilt, leaf spot, scab, litchi anthracnose, frost Phytophthora, leaf-eating insects, mango branch blight, bacterial black spot, sword zebra and so on. All relevant departments and monitoring stations should pay close attention to the weather changes and the occurrence of hot crop diseases and insect pests in this area, guide fruit growers to carry out production self-rescue in time, and conscientiously do a good job in the prevention and control of diseases and insect pests.

Monitoring and Control of Banana Diseases and insect pests

In view of the banana diseases and insect pests which are easy to occur after typhoon and rainstorm, the following control measures are suggested.

1. Enhance the growth of banana trees and improve their resistance to diseases and insect pests. After the typhoon and rainstorm, the leaves of the unbroken banana trees are blown more and the roots are hurt more, the wounds will be disorderly, and the growth of the whole banana trees is weak. It is suggested to spray foliar fertilizer and other copper preparations (to prevent bacterial and fungal rot), and to apply fertilizer when the leaves and roots are newly extracted 7-10 days later, so as to enhance the growth of banana trees and improve their resistance to diseases and insect pests.

2. Control of banana Fusarium wilt. Banana Fusarium wilt pathogen spreads with running water, and waterlogged rotten roots are susceptible to disease, so for banana plantations located in areas where Fusarium wilt occurs, it is necessary to eliminate stagnant water as soon as possible to avoid irrigation of the whole banana garden, resulting in Fusarium wilt in the whole garden.

3. Control of banana leaf spot and scab. Typhoon and torrential rain can blow a complete leaf of a larger banana tree into several small leaves, and there are many wounds on the leaves, resulting in easy invasion of spores. The strong wind blew the conidia of bacteria all over the garden, and Rain Water caused the spores to germinate easily. Therefore, after the typhoon and rainstorm, the chances of outbreaks of leaf spot and scab in banana orchards increased greatly. It is suggested that all hot crop pest monitoring stations and farmers should strengthen monitoring and early warning when the incidence of leaf spot and scab reaches 5%. It is required to pay close attention to the development of the disease, and prevention and control actions can be taken when the incidence reaches 10%. Banana leaf spot disease was prevented and treated by spraying leaves with propiconazole, tebuconazole, triadimefon and mancozeb. Banana scab was prevented and treated by spraying fruits and leaves with fungicides such as oxime, tebuconazole, pyrazole, flusilazole, nitrile, difenoconazole, tebuconazole and so on.

4. Control of banana weevil. The big banana tree was destroyed by the typhoon, and the measure taken to resume production is to cut off the banana tree at a distance of 1 meter and leave buds again. Banana pseudostem weevil is a banana stalk drill, after the typhoon, there are a large number of banana stem for pseudo-stem weevil reproduction, while banana trees hurt more roots and weaker trees, in this case the weevil is very easy to break out. When banana weevil is found, control measures should be taken immediately, using insecticides such as chlorpyrifos or phoxim to spray or infuse the solution from the base of the petiole, or to inject the solution at the height of 1.5 meters from the injured plant. The remnant plants of the banana garden and the normally growing banana trees should be treated.

Prevention and control of diseases and insect pests in litchi

At present, litchi in Hainan is in the first autumn shoot ripening or the second autumn shoot after fruit picking, and most of Guangdong and Guangxi are in the first autumn shoot. The super typhoon caused some branches to break and a large number of leaves to break, and even the whole tree was blown down or crooked. In order to restore the tree potential as soon as possible, cultivate strong autumn shoot-bearing mother branches, and do a good job in the prevention and control of diseases and insect pests, the following suggestions are put forward:

1. Eliminate stagnant water and clear the garden in time. It is urgent to dig a ditch to drain the stagnant water in the orchard to prevent the root system from being damaged by water for a long time; sawing the seriously damaged main branches in time, and pruning the branches seriously damaged by wind to promote new shoots.

2. Moderate righting and soil cultivation. For the litchi trees that are blown askew by the wind, the litchi trees should be properly righted and trampled on the soil in time, and protected by brackets with conditions to prevent the wind from being shaken.

3. Strengthen the management of fertilizer and water, apply one more available fertilizer appropriately, supplement organic nutrition on the leaf surface, and speed up the recovery of tree potential.

4. Prevent and control the occurrence of diseases and insect pests. Spraying fungicides in time to prevent the prevalence of anthracnose and other fungal diseases caused by a large number of wounds, it is recommended to apply prochloraz (Spock), manganese salt of prochloraz (Shibao), azoxystrobin (amicida), difenoconazole (Shigao), thiophanate methyl, carbendazim, mancozeb (Beck) and methomyl (concentration reference to the commodity manual). At the same time, we should pay close attention to the occurrence of many kinds of leaf-eating pests, especially to strengthen the control of litchi inchworm and leaf roll moth, according to the condition of new shoots in the orchard, we can choose BsSNPV, Bt, urea, avermectin, methamectin benzoate and chlorobenzamide, etc. (refer to the commodity manual for use concentration); in order to promote the growth of branches and leaves, we can spray foliar fertilizer.

Monitoring and control of mango diseases and insect pests

Focus on the occurrence and harm of mango branch blight and bacterial black spot, and guide fruit growers to take effective measures to ensure that there is no major outbreak of diseases and insect pests after the disaster.

1. Strengthen the management of water and fertilizer, strengthen the tree potential, cultivate strong branches and shoots, so as to reduce the harm of secondary disasters.

2. It is suggested to apply pesticides: bacterial black spot: Bordeaux solution, copper oxychloride, thiobacillus copper, quinolinol copper, mesophytin, chunramycin and so on. Branch blight: the choice of agents are triadimefon, thiobacillus copper, tebuconazole, propiconazole, stone sulfur mixture and so on. Anthracnose and scab: the selected agents are difenoconazole, promethazol, methyl topiramate and so on. Leafhopper and Spodoptera litura, leaf gall mosquito and leaf-cutting weevil and other pests: choose spray control, the main agents are avermectin, chlorpyrifos, cypermethrin, deltamethrin and so on.

Prevention and control of sisal zebra disease

The specific measures for the prevention and control of sisal zebra disease are as follows:

1. Strengthen the inspection of Ma Yuan and do a good job in flood control and drainage.

2. All field operations of damaged plants in diseased and sensitive fields (young hemp fields) are strictly prohibited and livestock damage is avoided to avoid wound infection; nitrogen fertilizer is applied to prevent overgrowth to avoid the decline of resistance.

3. During the rainy season, people are often sent to check the condition of Ma Tian. If diseased plants are found, they should choose to treat them when the weather is clear, dig out the diseased plants and burn them, and spray 2% copper sulfate solution at the diseased point or 1% Bordeaux solution around the diseased point.

4. 50% enamylmorpholine or 58% metalaxyl ·mancozeb (10% metalaxyl 48% mancozeb) or 72% metalaxyl ·mancozeb (8% metalaxyl 64% mancozeb) were sprayed on the leaves below the 45 ℃ angle of the disease center strain. 50% 100 times or 90% chloramphenicol (also known as aluminum triethylphosphonate, aluminum ethyl phosphate) wettable powder 45 times 90 times, 2 times in a row, once every 10 days. Considering that the occurrence of zebra stripe disease will be accompanied by sisal stem rot disease, in order to effectively control the "two diseases", it is necessary to spray 40% polysulfide suspension agent 70% 100 times on the basis of zebra disease control agents in this area.