MySheen

Hybrid Magnolia leaf blight

Published: 2024-11-08 Author: mysheen
Last Updated: 2024/11/08, The main symptoms occur on the leaves, and in severe cases, they can spread to petioles and buds. The disease spot mostly occurs at the leaf edge, the initial stage is faded green macula, watery, many disease spots are connected into pieces, the fan shape extends outward, the edge is dark brown, and the inside is grayish yellow, which can cause early defoliation. In a humid environment, black-gray grains appear on the fallen leaves. The cause of the disease is a fungal disease; the pathogen lives in the leaf bud and on the remnant of the diseased plant, and by means of airflow transmission, it can be infected directly from the stomata of the leaves with weak growth or physiological injury, and the wind speed is high.

The main symptoms occur on the leaves, and in severe cases, they can spread to petioles and buds. The disease spot mostly occurs at the leaf edge, the initial stage is faded green macula, watery, many disease spots are connected into pieces, the fan shape extends outward, the edge is dark brown, and the inside is grayish yellow, which can cause early defoliation. In a humid environment, black-gray grains appear on the fallen leaves.

The cause of the disease is a fungal disease; the pathogen lives in the leaf bud and on the remnant of the diseased plant, and by means of airflow transmission, it can be infected directly from the stomata of the leaves with weak growth or physiological injury. under the environmental conditions of high wind speed and low air humidity, it is beneficial to the occurrence of the disease, and the disease is serious in the high temperature and dry environment.

Control methods when flower buds and leaf buds are not unfolded, spray Baume 3 to 5 degrees stone sulfur mixture to the branches. Where there are conditions, wind barriers (windproof facilities) can be set up in winter to avoid the occurrence of physiological diseases. Increase foliar spray in spring to improve air humidity in the small environment. At the initial stage of the disease, 800 times of chlorothalonil and carbendazim were sprayed.

 
0