Control methods of powdery mildew of Lycium barbarum

Lycium barbarum powdery mildew is also called Lycium barbarum leaf spot, which is mainly harmful to leaves and fruits. The leaf infected with the disease is round to nearly round, the size is 2mm, the edge of the spot is brown, the center is gray, the back of the leaf is often black-gray mildew, and the fruit is infected with similar symptoms. Let's take a look at the prevention and control methods of Chinese wolfberry powdery mildew.

Develop symptoms

Lycium barbarum powdery mildew mainly harms the leaves, and the leaves are covered with white mildew spots (initial stage) and powder spots (later). White mildew spots and powder spots are not only the symptoms of the disease, but also the symptoms of the disease (pathogen conidiophores and conidia). In severe cases, the plant of Chinese wolfberry is white, which is quite eye-catching. The photosynthesis of diseased plants was blocked, which eventually caused the leaves to turn yellow and easy to fall off.

Induced pathogen

The pathogen of powdery mildew of Lycium barbarum is the genus Alternaria. In cold areas, the pathogen overwintered in the soil with the disease residue as a sexual fruiting body. In warm areas, the pathogen mainly carried out the initial invasion and re-invasion by apomorphic conidia, and completed the annual cycle of the disease, and there was no obvious overwintering period. Warm and humid weather or planting environment is conducive to the disease, but the spores of the pathogen have the characteristics of drought tolerance, which can still germinate and infect the disease normally under the condition of high temperature and drought.

Disease condition

The pathogen of powdery mildew of Chinese wolfberry overwintered with mycelium or conidia in the withered branches and leaves of Chinese wolfberry or in the soil with diseased fruit, and the conidia spread through wind and rain in the following year to carry out primary infection and re-infection to expand the damage. It is easy to suffer from high temperature and rainy years, high soil moisture, moist air, lack of soil fertilizer and plant weakness.

Prevention and cure method

1. Select improved varieties of Lycium barbarum, such as Ningqi No. 1, clean the Qi garden in time after falling leaves in autumn, remove diseased leaves and fruits, concentrate and bury deeply or burn them, so as to reduce the source of bacteria.

2. Strengthen cultivation management, advocate compost made by Japanese enzyme bacteria retting, increase phosphorus and potassium fertilizer, and enhance disease resistance.

3. In June, 70% mancozeb wettable powder 500 times liquid or 75% chlorothalonil wettable powder 600 times liquid, 64% poison alum wettable powder 500 times liquid, 30% green Debao suspension 400 times liquid, once every 10 days or so, continuous prevention and treatment for 2 times 3 times, and stop using drugs 7 days before harvest.