MySheen

Identification and control of black spot of rose

Published: 2024-11-23 Author: mysheen
Last Updated: 2024/11/23, The disease is common and does serious harm, resulting in a large number of fallen leaves of rose and huge losses. The pathogen is a fungus of the genus Actinomyces. First, at the beginning of symptom recognition, brown radial plaques appear on the leaf surface, and then gradually enlarge into round or subcircular spots with a diameter of 412 mm.

The disease is common and does serious harm, resulting in a large number of fallen leaves of rose and huge losses. The pathogen is a fungus of the genus Actinomyces. First, at the beginning of symptom recognition, brown radial disease spots appear on the leaf surface, and then gradually expand into round or near-round disease spots, with a diameter of 412 mm; in severe cases, the lower leaves fall off in the early stage, gradually spread upward, and eventually the upper leaves will lose light. Rainy and humid is the main condition for spore production, there are water droplets on the leaf surface, and under the appropriate temperature, it can invade in 6-10 hours and appear symptoms in 3-6 days. The disease resistance of rose of yellow flower line is poor. Second, prevention and control techniques 1. Field cultivation, selection of disease-resistant varieties. 2. Cut off the diseased branches in winter, clean up the fallen leaves in the field or in the basin, and burn them. 3. Pay attention to spray protection. Starting from April, spray Bordeaux solution with 1D and 160 Bordeaux once a week; from June to August, you still need to spray Bordeaux liquid, or 50% carbendazim wettable powder 500 times, or 75% chlorothalonil wettable powder 500 times; or 70% mancozeb wettable powder 500 times 600 times.

 
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