Tomato bacterial wilt is a bacterial disease that causes whole-plant wilt. When the tomato plant is about 30 centimeters tall, bacterial wilt begins to show symptoms. In the early stage of the disease, the diseased plants wilt during the day and recover in the evening, and the color of the diseased leaves becomes lighter. If the soil is dry and the temperature is high, the entire plant will wilt in 2 to 3 days. If the temperature is low, it rains continuously, or the soil moisture content is high, the diseased plants can continue to die after a week, but the leaves remain green or slightly lighter, so it is called bacterial wilt. The epidermis of the diseased stems is rough, and adventitious roots or buds proliferate in the middle and lower parts of the stems. When the humidity is high, 1 to 2 cm patches that are initially water-soaked and then turn brown can be seen on the diseased stems. Cut the diseased stem transversely. The vascular bundles of the diseased stem will turn brown and be squeezed by hand. Milky white bacterial pus will not escape from the vascular bundles on the cut surface.
Biopesticides have not yet been widely used. Currently, there are three categories of biopesticides: biochemical pesticides, microbial pesticides, and botanical pesticides. Today, chemical pesticides are still the main means of preventing and controlling tomato gray mold. Carbendazim, thiophanate-methyl, procymidone, iprodione, pyrimethanil, picoxystrobin, hexaconazole and ethocarb are used for sterilization. Mainly agents. If these drugs are used excessively for a long time, they will lead to excessive residues in agricultural products and environmental pollution, and will also cause Botrytis cinerea to develop drug resistance. There are currently dozens of biopesticides used on tomatoes. Biopesticides have low toxicity, are safe for the environment, and are not prone to resistance:
The main biogenic pesticides used to prevent and control tomato gray mold include 0.5% small Berberine aqueous solution, 5% carvacrol aqueous solution, 1% matrine soluble aqueous solution, 1.5% Sophora flavescens and osthole aqueous solution, 0.3% eugenol soluble aqueous solution, 2.1% clove and carvacrol aqueous solution agent, 300 million CFU/Trichoderma harzianum wettable powder, 100 billion pcs/g Bacillus subtilis wettable powder, 200 million pcs/g Trichoderma wettable powder, 100 million cfu/Trichoderma harzianum water-dispersible granules, etc. variety.
Water-soluble Paecilomyces lilacinus agent biopesticide is a biological control agent developed for tomato root-knot nematode disease. The new tomato root-knot nematode control agent, Paecilomyces lilacinus agent, has rapid reproduction and vitality. Strong, safe and non-toxic; Paecilomyces lilacinus secretes and synthesizes a variety of organic acids, enzymes, physiologically active substances, etc.
Microbial control, such as gold planting special (original solution), can be sprayed on the leaves Or root irrigation can enhance the disease resistance of tomato plants and prevent tomato bacterial wilt.
Editor's note: Biopesticides are a renewable resource that basically does not contain any synthetic ingredients. It has the advantages of safety, no toxic side effects, and does not pollute the environment. In the future, biopesticides will account for an increasing share of pesticides.