A Detailed Explanation of Integrated Pest and Disease Management Strategies for Walnut Trees

  There are many different methods for controlling walnut tree pests and diseases. In practice, the principle of "prevention first, integrated management" should be followed, with agricultural control as the foundation, rational use of pesticides, and integrated management measures combining biological control, physical control and chemical control, so as to control pests and diseases economically, safely and effectively, thereby achieving the goals of increasing walnut yield, ensuring quality, and protecting the ecological environment and people's health.

  Agricultural control is the key focus of integrated pest and disease management measures. It can reduce the use of pesticides and uses agricultural measures such as site selection and planning and design, as well as cultivation management, to control pests and diseases. The main measures include: selecting disease-resistant varieties; applying more organic fertilizer, improving the soil, and pruning rationally, removing insect cocoons during pruning, and enhancing tree vigor; whitewashing the trunk in late autumn to improve the tree's disease resistance; carrying out orchard soil turning and orchard cleanup to reduce sources of disease and pests, promptly picking up fallen fruit, clearing weeds and fallen leaves in the orchard and destroying them, plowing the soil around the tree base to destroy pest habitats and inhibit their development, and clearing overwintering pests; and growing grass and intercropping in walnut orchards to increase beneficial microorganisms and improve the ecological conditions of the orchard.

  For diseases, physical control mainly refers to scraping off diseased spots; for pests, it mainly refers to trapping, catching and blocking pests. Trapping refers to using the tendencies of pests, catering to their preferences, and artificially luring and gathering pests to eliminate them, for example, using blacklight lamps (ultraviolet lamps) to trap phototactic pests. Catching refers to using manpower and simple machinery to catch pests that are gregarious or feign death, such as using bamboo poles to strike branches and knock down larvae, or shaking them down to catch adult scarab beetles during their adult stage. Blocking refers to artificially setting up barriers according to the activity habits of pests to prevent the spread and migration of larvae or some adults that are not good at flying.

  Biological control mainly uses the natural enemies of pests and beneficial microorganisms to control pests and diseases. The main natural enemies of pests include ladybugs, green lacewings, wasps, ants, hoverflies, parasitic wasps and parasitic flies. Insecticidal bacteria include Bacillus species and Bacillus thuringiensis; fungi include Beauveria bassiana and Metarhizium anisopliae; viruses include the nuclear polyhedrosis virus of the mulberry tussock moth and slug moth viruses. Microbial disease control mainly uses the metabolites of various fungi, namely antibiotics, such as polyoxins and streptomycin. Insect hormones can also be used as sex attractants to trap and kill male pests, specific pest growth inhibitors can be used to control pests, and biological pest control can also be carried out by raising chickens and attracting insectivorous beneficial birds.

⟦NL>   Chemical control is currently the most widely used method for controlling pests and diseases. It acts quickly and has a wide range of uses, but it may lead to pest and disease resistance, and it can pollute soil and groundwater, cause phytotoxicity, easily kill natural enemies, and pesticide residues in fruit are harmful to human health. Therefore, in consideration of ensuring human health, protecting the environment and reducing pest and disease resistance, highly toxic pesticides and even extremely toxic pesticides should be prohibited, and it is recommended to promote and apply biogenic pesticides, mineral-source pesticides, plant-source pesticides, insect growth regulator types and others to control pests and diseases, ensuring high yield and high quality of pollution-free walnuts.