How to Avoid Plant Diseases and Insect Pest Resistance

Due to repeated use or abuse of pesticides for a long period of time, there have been many kinds of pesticides in the prevention and control of plant diseases and insect pests when the efficacy decline, or even invalid. In order to reduce the occurrence of drug resistance, the following points should be noted when using pesticides: Alternately use pesticides. Alternate administration is the use of pesticides that have completely different mechanisms of action during the growth period of a given plant. It can not only improve the control effect, but also delay the use of a good variety of pesticides. For example, pesticides include organic phosphorus preparations, pyrethroid preparations, carbamate preparations, organic chlorine preparations, and biological preparations, and their action mechanisms are different. Pesticide species in the same type of preparation can also be used interchangeably, but it must be ascertained whether there is cross-resistance between them. For example, after the locust has developed resistance to dimethoate, dichlorvos can no longer be used because locusts are also resistant to dichlorvos. But you can choose to kill the pine. In bactericides, inhalation of bactericides is generally more likely to cause drug resistance, such as benzimidazole bactericides (carbendazim, thiophanate, etc.), antibiotic bactericides, and the like. However, the contact bactericide is not likely to cause drug resistance, so it is a better rotation combination. Such as Daisen, inorganic sulfur preparations, copper preparations are all good round varieties. Mixed pesticides in science. Mixing the agents with different modes of action and mechanisms can also slow down the occurrence of drug resistance, and can also cure a variety of diseases and insect pests, enhance drug efficacy, reduce pesticide use, and reduce costs. For example, after the resistance to pyrethroid pesticides, the combination of organophosphorus pesticides and pyrethroid pesticides can have a certain inhibitory effect on pest resistance. In addition, such as renomycin and mancozeb mixed, carbendazim and sterilization Dan mixed, are more successful mixed methods. Once drug resistance has emerged, switching to mixed formulations often works. However, the mixed use must be scientific and reasonable and cannot be blindly mixed. Moreover, a mixed pesticide cannot be used for a long time and it must be used alternately. Otherwise, drug resistance will also occur, and it may also cause multi-resistance in pests, that is, the organism will produce resistance to various pesticides at the same time. Intermittent use or deactivation of pesticides. When a pesticide has caused drug resistance, if it is stopped for a period of time, the phenomenon of drug resistance may gradually decline or even disappear. For example, after monocrotophos resistance occurs, drug resistance may disappear after several years of use. Apply synergist. Synergists can increase the biological activity of pesticides and increase their efficacy. Therefore, the addition of a certain amount of synergist in certain pesticides can also delay or overcome the occurrence of drug resistance. Currently, there are synergists in addition to fenvalerate and malathion in the 21% synergistic cyanol concentrates currently sold on the market. In addition, the effective dose of the drug and the uniformity of deposition distribution are also crucial for pest control. Therefore, for different plants and different pests, proper application techniques should also be selected so that the distribution of the pesticides on the plants is evenly distributed, so that better control effects can be obtained with less dosage.