For orchards, apple bagging is only the most basic means of safety protection, such as preventing the attachment of germs caused by wet soil after rainy days, preventing the negative effects of hail or other bad weather, and isolating germs from rotten fruits.
But it should be noted that bagging apples is not almighty. Don’t think that you don’t need to spray medicine after bagging. Even after bagging, there may still be diseases. The following are some common answers to pest control techniques after bagging in orchards.
Q: What are the symptoms and conditions of brown spot disease, and what kind of medicine is best for prevention and treatment?
A: Brown spot disease manifests itself in three forms in the early stage: one is whorl, the other is mixed, and finally becomes deciduous, which is its symptom. There are three conditions for the occurrence: first, high temperature and high humidity, second, insufficient light due to the closed canopy of the orchard, and third, untimely or improper spraying.
7-10 days after bagging, spray 1:2:200 Bordeaux mixture, no less than 3 times during the growing season.
Q: What is the difference between the symptoms and causes of black spot and red spot disease?
A: In the early stage of black spot disease, small needle-like black spots appear around the calyx of the fruit, and the diameter of the black spots gradually expands like sesame/mung bean. Disease spots only occur on the skin of the fruit and not on the pulp; Red spot disease occurs after apples are removed from the bag. If it rains, most of them occur on the side facing the sun, forming many needle-shaped red spots.
Black spot disease is easily caused by Fusarium fungus infecting the peel surface, and calcium deficiency and boron deficiency can also cause black spot disease. Medicines with poor suspension rates can also cause or aggravate black spot disease when used before bagging. Red spot disease is usually caused by leaf spot infection.
Q: What’s the matter with apple leaves withered? What are the possible reasons for withering?
A: There are two reasons for the withering of apple leaves. One is the withering of leaves caused by potassium deficiency; the other is phytotoxicity, which causes abnormal color on the edge of the leaf or the entire leaf, brown on the edge of the leaf, and scorched brown withered shape.
Q: What are the main types of red spiders on apples? What are the hazards?
A: The red spiders on apples mainly include hawthorn red spiders and apple red spiders. The damage is characterized by sucking leaves, causing chlorosis and spots. The characteristic of occurrence is fast. It only takes 5 to 7 days. Hawthorn red spider harms the reverse side, and apple spider mites occur on the front side, and its eggs may have positive and negative sides.
Q: Azocyclotin is an effective medicament for the prevention and control of red spiders. What problems should be paid attention to in the process of using it?
A: In the process of using azocyclotin, it should be noted that the isolation time from alkaline drugs should be long, especially the Bordeaux mixture. If the interval with the Bordeaux mixture is short, the efficacy of the drug will easily lose, and it will not have a certain effect, which is easy to cause Drug damage.
Q: Besides chemical methods, are there other ways to deal with insect pests such as tumblebug and peach fruit moth?
Sex attractants and insecticidal lamps are the key promotion measures for fruit tree pest control. These two methods will not pollute the environment, and can effectively reduce the frequency and amount of pesticide use, which are essential for the production of pollution-free fruits.