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Prevention and control of spot disease of impatiens

Published: 2024-11-08 Author: mysheen
Last Updated: 2024/11/08, First, damage symptoms: disease scientific name: PhyllostictaimpatientisFautr. Impatiens spot disease is mainly harmful to leaves. Primary yellow spots, gradually expanding around into a round spot, the size of 2~5mm. The center of the post-plaque is light brown or grayish white, the edge is brown slightly raised,-dead black particles, that is, the pathogen conidium. If the bacteria invade from the leaf tip or leaf edge, the leaf tip will die and the leaf edge will be anxious. The disease occurred in Guangdong and Yunnan from July to September. 2. Morphological characteristics of pathogenic bacteria: pathogen is called Feng.

First, damage symptoms: disease scientific name: PhyllostictaimpatientisFautr. Impatiens spot disease is mainly harmful to leaves. Primary yellow spots, gradually expanding around into a round spot, the size of 2~5mm. The center of the post-plaque is light brown or grayish white, the edge is brown slightly raised,-dead black particles, that is, the pathogen conidium. If the bacteria invade from the leaf tip or leaf edge, the leaf tip will die and the leaf edge will be anxious. The disease occurred in Guangdong and Yunnan from July to September.

Second, the morphological characteristics of the pathogen: the pathogen is called impatiens leaf spot mold, which belongs to half-known fungi. The conidium is scattered on the leaf surface, globose to subglobose, 82-102um in size. The conidia are oval, colorless and contain 1-2 oil globules, the size of 3.0-5.0X2.0-3.0 (um).

Third, the characteristics of the disease: the pathogen overwintered on the diseased body with conidia, and when the conditions were suitable in the next year, conidia were transmitted by airflow and Rain Water to carry out primary infection and re-infection.

IV. Prevention and control methods

(1) timely removal of diseased fallen leaves.

(2) if necessary, spray 40% chlorothalonil suspension 500 times or 80% spray gram wettable powder 600 times, 70% mancozeb wettable powder 500 times.

Commonly used agents: 70% mancozeb wettable powder 40% chlorothalonil suspension

6. The latest special effect agents: Pectinomyces amicidarbazim, etc.

 
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