Prevention and Control Techniques for Kiwifruit Ulcer Disease
Kiwifruit Ulcer Disease Symptoms
Kiwifruit ulcer disease is one of the significant diseases affecting kiwifruit production. It typically occurs during the spring sap flow period, flowering stage, and autumn. Mild cases result in reduced yields, while severe cases can lead to tree death.
The symptoms of kiwifruit ulcer disease include:
-
Initial Leaf Symptoms: Small, chlorotic spots appear on the leaves, resembling water-soaked lesions. These spots later develop into irregular or polygonal brown lesions, with distinct yellow halos around the edges.
-
New Shoots and Main Stem: Infected new shoots and main stems turn black and die off. Flower buds are affected and fail to open. The affected main stems and branches exhibit water-soaked tissues, softening, and swelling.
Prevention and Control Techniques for Kiwifruit Ulcer Disease
1. Prune and Burn Dead Branches
During winter, gather and burn dead branches and leaves infected with the pathogen. In early spring, prune diseased and insect-infested branches, long shoots, and drooping branches to reduce the spread of the disease.
2. Apply Organic Fertilizers
Regularly apply organic fertilizers to kiwifruit plants to improve soil structure, enhance nutrient absorption efficiency, and boost disease resistance.
3. Topical Treatment
When bacterial ooze or brownish-black exudate flows from kiwifruit tree trunks or branches, make several incisions with a knife and then apply a mixture of thiophanate-methyl solution and full-fat cow dung. Repeat the application the next day for severely affected areas.
4. Root Drenching
Apply a 500-fold solution of streptomycin sulfate to the soil beneath the affected branches of kiwifruit trees to promote absorption by the root system and translocation to various plant tissues.
5. Chemical Treatment
After the onset of spring infections, make three incisions with a small knife on small wounds or lesions and then apply a 50-fold solution of streptomycin sulfate. During the peak infection period, apply a small amount of undiluted solution to facilitate rapid bactericidal action. For large lesions or cuts, apply a mixture of medical vaseline and copper sulfate after removing the diseased tissues.
Implementing these prevention and control techniques for kiwifruit ulcer disease is essential for improving the quality and yield of kiwifruits.
