Gray Mold: How to Identify, Control, and Prevent Botrytis
Grey Mold is caused by the infection of botrytis cinerea, is a fungal disease, Botrytis cinerea is a common and difficult to prevent and control fungal disease, crops infected botrytis cinerea, will become soft rot, collapse, the final disease seedlings rot blight died, so we must timely take scientific and reasonable methods to prevent and control botrytis cinerea.
Common grey mold diseases of crops are strawberry grey mold, tomato grey mold, cucumber grey mold, grape grey mold, pepper grey mold.
Low temperature and high humidity is an important reason for the occurrence of Botrytis cinerea of tomato. The optimum temperature for the development of botrytis cinerea is 16-23 ℃, and the temperature above 25℃ is not conducive to the spread of the disease. Diseases are easy to occur and prevail when relative humidity is maintained above 90%.
The ultraviolet ray in the sunshine can effectively prevent the tomato from growing up, and the tomato in the greenhouse is in the weak light environment for a long time, resulting in weak growth and disease resistance. In addition, light irradiation generally has an inhibitory effect on the formation of Botrytis cinerea, and the light environment in the greenhouse weakens this effect.
The stigma that remains or petal is infected more first, extends to the fruit later, causes fruit skin to be hoar white, has thick gray mildew layer, shows water rot shape.
The onset of leaf blade from the tip, along the veins into a "V" shape to expand inwards, grayish-brown, with dark and light border striate line.
Grey mold disease seedling color is light, the leaf, the petiole is gray-white, water stain shape, the tissue softens to rot, the surface has grey mold when high humidity. Young stems in the petiole at the base of the initial irregular water spots, quickly become soft rot, constriction or collapse, the final disease seedlings rot and die.
Weak light, relative humidity is more than 90% or there is water film on the surface of the seedlings prone to disease. Flowering is the most susceptible to disease, airflow, irrigation, and agricultural operations from the wound, aging organ invasion.
In case of continuous rainy or cold current windy weather, the wind is not timely, the density is too large, the seedling is short, when the seedling transplant injury root, injury leaves, will aggravate the disease.
Selection of good seeds, strict seedling care: the selection of good varieties can improve the ability of tomato against gray mold. the attention does not take soil to raise seedling or cent seedling in disease area greenhouse, in case seedling infects germ.
Clean the garden: remove the stubble and dead leaves from the greenhouse before planting. At the early stage of the disease, timely remove the diseased leaves, flowers, fruits, and the lower yellow leaves, old leaves, to the outdoor buried or burned, keep the greenhouse clean, reduce the source of primary infection.
Reduce the humidity in the greenhouse: high ridge cultivation, the use of drip irrigation water supply, to avoid flooding, watering the best in the morning in the sunny day, avoid overcast rain watering, can effectively reduce the indoor humidity.
Common grey mold diseases of crops are strawberry grey mold, tomato grey mold, cucumber grey mold, grape grey mold, pepper grey mold.
1. Cause of Grey Mold Diseases
Cold and rainy in spring, high humidity in the greenhouseLow temperature and high humidity is an important reason for the occurrence of Botrytis cinerea of tomato. The optimum temperature for the development of botrytis cinerea is 16-23 ℃, and the temperature above 25℃ is not conducive to the spread of the disease. Diseases are easy to occur and prevail when relative humidity is maintained above 90%.
The ultraviolet ray in the sunshine can effectively prevent the tomato from growing up, and the tomato in the greenhouse is in the weak light environment for a long time, resulting in weak growth and disease resistance. In addition, light irradiation generally has an inhibitory effect on the formation of Botrytis cinerea, and the light environment in the greenhouse weakens this effect.
2. Symptoms of Grey Mold
Grey mold can occur in flowers, fruits, leaves, and stems of crops.The stigma that remains or petal is infected more first, extends to the fruit later, causes fruit skin to be hoar white, has thick gray mildew layer, shows water rot shape.
The onset of leaf blade from the tip, along the veins into a "V" shape to expand inwards, grayish-brown, with dark and light border striate line.
Grey mold disease seedling color is light, the leaf, the petiole is gray-white, water stain shape, the tissue softens to rot, the surface has grey mold when high humidity. Young stems in the petiole at the base of the initial irregular water spots, quickly become soft rot, constriction or collapse, the final disease seedlings rot and die.
3. Environmental Factors of Grey Mold Disease
With the sclerotia in the soil or the disease residue in the summer, the temperature in 20 ~ 30℃. Bacteria are resistant to low temperature, 7-20 ℃ a large number of spores, seedling stage temperature in the shed 15-23 ℃.
Weak light, relative humidity is more than 90% or there is water film on the surface of the seedlings prone to disease. Flowering is the most susceptible to disease, airflow, irrigation, and agricultural operations from the wound, aging organ invasion.
In case of continuous rainy or cold current windy weather, the wind is not timely, the density is too large, the seedling is short, when the seedling transplant injury root, injury leaves, will aggravate the disease.
4. Prevention and Treatment of Grey Mold Disease
Agricultural control
Ozone sterilization treatment of seeds: before seeding, soak seeds with ozone water for 40-60 minutes; High-dose ozone air shed sterilization: before seedling transplantation, close the vent and sterilize the air shed with high-dose ozone gas.Selection of good seeds, strict seedling care: the selection of good varieties can improve the ability of tomato against gray mold. the attention does not take soil to raise seedling or cent seedling in disease area greenhouse, in case seedling infects germ.
Clean the garden: remove the stubble and dead leaves from the greenhouse before planting. At the early stage of the disease, timely remove the diseased leaves, flowers, fruits, and the lower yellow leaves, old leaves, to the outdoor buried or burned, keep the greenhouse clean, reduce the source of primary infection.
Reduce the humidity in the greenhouse: high ridge cultivation, the use of drip irrigation water supply, to avoid flooding, watering the best in the morning in the sunny day, avoid overcast rain watering, can effectively reduce the indoor humidity.
Biological Control
Dora Trichoderma harzianum is the biocontrol agent on soil micro-environment, disease control & root system growth. The brightest spotlight, it has an excellent ability to eliminate damaging fungal pathogens in soil, and form a nature defensive bond to Guard and stimulate roots for plants.
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