In recent years, China's fruit tree planting industry has entered a period of rapid development, and the problem of pesticide pollution in the process of disease and pest control of fruit trees has been widely concerned by all sectors of society. In order to improve the yield and quality of fruit trees, some fruit farmers will blindly and excessively use pesticides when encountering disease and pest problems, and it has been proved that the large use of pesticides cannot completely solve the problem of fruit tree diseases and insect pests, but will lead to different degrees of pollution of fruit trees and the environment. Therefore, combined with work practice, the author analyzes the problem of pesticide pollution in the prevention and control of fruit tree diseases and insect pests, and proposes targeted treatment measures.
<h1>1 Pesticide pollution problems in the control of fruit tree diseases and insect pests</h1>
From the current situation, the problem of pesticide residues in China's fruits has been very severe, of which the pesticides that exceed the standard residue are mainly pesticides containing organic phosphorus, permethrin and other substances, especially in economically underdeveloped areas, due to improper or excessive use of pesticides to control fruit tree diseases and insect pests, which eventually leads to fruit and environmental pollution.
1.1 Pesticide contamination of fruit trees
It is mainly manifested in two aspects, one is left in the branches and leaves of the fruit and the surface part of the fruit, and the other is left in the cuticle and internal tissue of the fruit tree. There are many ways to cause pesticide residues inside and outside fruit trees, such as pesticides that are difficult to dissolve in water will be left in large quantities
On the surface of the fruit tree, after chemical action, a water-soluble substance is formed, which gradually penetrates into the interior of the fruit tree. From the perspective of harm, pesticide pollution will not only affect the photosynthesis of fruit trees, but also restrict the growth of fruit trees and the development and maturity of fruits, which will lead to the direct death of fruit trees in serious cases.
1.2 Environmental pesticide pollution
Most pesticides are applied directly, and this pesticide will flow into the water body under the wash of water or rainwater, resulting in pesticide pollution in the water body. The problem of pesticide pollution in the soil is similar to the water pathway, and the soil of the orchard is polluted by pesticides, which will lead to a decline in soil quality, poor soil permeability, damage to the soil structure and soil fertility is difficult to give full play to, affecting the growth and development of fruit trees. Pesticides scattered in the air can pass through the respiratory tract, skin and digestive system directly into the human and animal bodies, causing direct harm.
<h1>2 Control measures for pesticide pollution in the control of fruit tree diseases and insect pests</h1>
2.1 Strengthen the cultivation and management of fruit trees, establish prevention and control measures with the health of fruit trees as the main body to control fruit tree diseases and insect pests, produce high-quality fruits without pesticide residue pollution, and vigorously promote comprehensive agricultural control methods, which is the most economical and safest method. Specific measures: (1) High standards for the construction of the park. Starting from the source, once the causal tree is planted, it grows in a fixed place for a long time, and the environmental conditions such as climate, soil and water source of the cultivation site directly affect the growth and development of the fruit tree and the economic benefits. Therefore, the choice of garden land is comprehensively considered from the conditions of terrain, climate, soil and water source, and the garden land is selected according to local conditions. (2) Cultivate and plant disease- and insect-free seedlings. To cultivate healthy (disease-free) seedlings, it is necessary to choose robust and disease-free propagation materials, breed and breed in the formal (standardized) mesh chamber greenhouse, large seedlings or nutrition cups (containers) seedlings have developed root systems, high transplanting quality, slow seedlings in a timely manner or avoid the slow seedling stage, easy to manage, promote the rapid growth of young trees, such as citrus field planting for one year into fruit, slow down or reduce the probability of infection with diseases and insects in the young stage of fruit trees, citrus trees can reduce the chance of yellow dragon disease infection. (3) Strengthen cultivation management and enhance tree resistance. Follow up in time after planting fruit trees, do a good job in the daily management and protection of orchards such as reasonable fertilization, irrigation, loose soil weeding, reasonable pruning, reasonable intercropping and planting of green manpower, etc., to create a good environment conducive to the growth of fruit trees, so that the tree itself can play an active defense against diseases and insects.
2.2 Biological and physical and mechanical methods of coordinated combat for the control of pests and diseases
Biological method: that is, full protection and use of the role of local natural predators or artificial introduction and reproduction to release natural enemies, the use of food chain to achieve the goal of "insects to cure insects". For example, grasshoppers, small flower bugs, ladybugs are natural enemies of mites, aphids and aphids, red-eyed bees can control apple leaf curl moths, apple small heartworms, wood lice jumping wasps are natural enemies of pear wood lice, and daylight bees are natural enemies of apple aphids. In order to give full play to the role of natural enemies, the types of drugs used should be strictly controlled during the occurrence of natural enemies, and no drugs should be used or reduced. At the same time, grass or intercropping honey source plants are planted between orchard rows to attract natural enemies, or artificial feeding is introduced to release natural enemies and increase the number of natural enemy populations.
Physical and mechanical methods; according to a certain biological characteristic of the disease and insect, supplemented by simpler machinery or measures, the disease and insect pest are directly eliminated. Pests such as elephant beetles, leaf beetles, and celestial cattle have pseudo-death and can be artificially hunted; pests such as moths, scorpions, and scarabs have phototropism and can be booby-trapped by light; pests such as aphids and whiteflies have yellowing and can be lured by yellow plates; like white star scarabs, small blue-and-white scarabs, etc., have a tendency to precocious apples, and can put early-ripening apples on tree branches for booby traps; sugar and wine vinegar traps can trap peach borers, leaf curl moths, fruit-sucking nocturnal moths, citrus fruit flies and other fruit tree pests.
2.3 Scientific and rational use of pesticides
2.3.1 Appropriate symptomatic medication. There are many kinds of diseases and insects in fruit trees, the varieties of pesticides are also diverse, all kinds of pesticides have certain control objects and scope, to ensure the pertinence of pesticide application, it is necessary to combine the occurrence of pests and insect pests in a timely manner, such as the use of insecticides for the prevention and control of pests, the use of mites for the control of pests, the use of fungicides for the prevention and control of diseases, the use of herbicides for the control of weeds; for the pests of the chewing mouthpiece, the gastric poison and the touch killer are selected, and the pests of the stinging mouthpiece should be selected as touch and systemic agent.
2.3.2 Dosage of drugs in an appropriate amount. Use agents that only kill pests and do not affect or have little effect on predators. Some acaricides and aphids only have a toxic killing effect on mites and aphids, and are safe for natural enemies and can be used as the preferred agent for prevention and control. Determine the optimal concentration and dosage of pesticide use based on pest and disease pest and pesticide species and fruit tree development period. For example, for the control of shell insects, use pine resin compound 18 to 20 times liquid, winter qingyuan with 8 to 10 times liquid; use 95% motor oil emulsion 100 to 200 times liquid, but use caution during the bud and coloring periods. Therefore, the dose and frequency of pesticide use instructions should be applied, and the dose and frequency of use should be avoided blindly increasing the dose and increasing the number of uses, so as to reduce the impact on the environment and fruit quality and safety.
2.3.3 Mixing and rotation of medications. In fruit tree production, if the same pesticide or the same type of pesticide is used for a long time for an insect or disease, it will lead to the resistance of bacteria and pests, resulting in a continuous decline in the effectiveness of pesticide prevention. Citrus lice have developed resistance to chlorpyrifos, highly potent permethrin, and imidacloprid. The rational mixing of chemical pesticides can not only treat a variety of diseases and insect pests, but also prevent or slow down the resistance of diseases and insects, but it is necessary to consider the interaction resistance between mixed pesticides, synergistic effects and the appropriate proportion between individual agents, and promote scientific and rational mixing. Remember to use the same agent for a long time in the same orchard, and several pesticides should be alternately rotated to improve the efficacy and slow down the rate of resistance of diseases and insects.
This paper analyzes the current pesticide pollution problems in the prevention and control of fruit tree diseases and insect pests in China, and discusses its specific treatment measures. In the production process of fruit trees, it is inevitable that pests and diseases will occur, but this does not mean the use of pesticides for control
Pesticides can be used blindly or in excess. In the actual fruit tree cultivation and management work, it is necessary to establish a green prevention and control system for fruit tree diseases and insect pests with non-chemical control measures such as agronomy, biological or physical control as the main content, so as to maintain a sustainable development of the orchard ecosystem.
Author: Tang Mingli Zhang Suying's friend Junyang Tingmi