What specific fungicide works for strawberry gray mold? Latest recommended treatments
Strawberry gray mold occurs in all strawberry-growing regions of China. After the 1970s, the disease gradually worsened, and it is especially severe in the south when the fruit-picking period coincides with spring rains. It often causes a diseased-fruit rate of around 30% in susceptible varieties with fruit rot, and in severe cases it can reach over 60%, greatly affecting strawberry yield and quality. Now let us take a look at what specific fungicide works for strawberry gray mold!
Symptoms of strawberry gray mold
Strawberry gray mold usually starts during the flowering stage. The pathogen first infects flowers that are about to fade or weaker parts, causing the flowers to become light brown, necrotic and rotted, and producing a gray mold layer. Leaves are mostly invaded from the edges of old yellow leaves at the base, forming “V”-shaped yellow-brown spots, or infected along where petals have fallen, forming nearly round necrotic spots with indistinct concentric rings and relatively sparse gray mold on them. Fruit infection mostly starts from remaining petals or parts near or touching the ground, and can also invade from parts that came into contact with diseased residue early on. It initially appears as water-soaked gray-brown necrosis, then the color darkens, the fruit rots, and a dense gray mold layer forms on the surface. When petioles are affected, they become light brown, necrotic and shriveled, with sparse gray mold on them.
Characteristics of strawberry gray mold
The strawberry gray mold pathogen overwinters in the soil as mycelium and conidia with diseased residue or as sclerotia. It spreads through airflow, watering or agricultural activities. Disease can occur at temperatures of 0-35°C and relative humidity above 80%, and conditions suitable for disease development are temperatures of 0-25°C and humidity above 90%, or standing water on plant surfaces. High air humidity, or rain after watering, or low-lying waterlogged areas are especially favorable for the occurrence and development of this disease. According to another survey, flat-bed planting or laying plants down and covering with film results in severe disease, while high ridges and plastic film cultivation result in mild disease.
Prevention and control of strawberry gray mold
1. After harvest, thoroughly remove diseased residue and fallen leaves. Before transplanting or preparing seedbeds, spray the greenhouse film, soil and walls to disinfect and sterilize, and also spray New High Lipid Film to enhance efficacy.
2. Use high-ridge plastic film mulching or drip irrigation water-saving cultivation, choose ultraviolet-blocking film to inhibit sclerotia germination, and spray for control before flowering, during flowering and fruit set, and before watering to promote fruit development, focusing on protecting flowers and fruit, coordinating nutrient balance, preventing strawberry malformation, and achieving high yield and quality. After watering, increase ventilation. Use Meizhi 70-100 times dilution for spraying.
3. Disease treatment: Once disease occurs, promptly and carefully remove diseased leaves, flowers and fruit, put them in plastic bags, take them out of the greenhouse and dispose of them properly. After disease occurs, appropriately raise the management temperature.