Kill powdery mildew on tomato plants with natural enemies
Ho Chi Minh City Center for Research and Development of Hi-tech Agriculture has studied and applied the bait bug (Orius sp.) and small spider (Amblyseius sp.) to control whitefly (Bemisia tabaci) on tomato plants grown in greenhouses.
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Cherry tomatoes are one of the crops that are damaged by many pests and diseases, even though grown in greenhouses, they are still damaged by some small insects, such as thrips, red spiders, and whiteflies. In which, whitefly is the main pest and transmits leaf curl disease, affecting the yield and quality of cherry tomatoes.
To control powdery mildew, the usual control method is to spray pesticides. However, the use of many pesticides for a long time and continuously causes drug resistance, environmental pollution, and affects the health of producers and consumers. Therefore, using parasitic natural enemies is a biological control measure selected in the current period. This direction has been studied and used by many countries around the world for a long time, however, it has received little attention in Vietnam.
Bugs and small spiders were collected by the research team in the wild in vegetable growing areas of Ho Chi Minh City, then bred in the laboratory, at a temperature of 27ºC ± 2 and humidity of 75% ± 2.
Release small spiders with the quantity of 2/plant, equivalent to 4,000/1,000m², into the cherry tomato garden in the greenhouse. For bugs, stocking density is 1 insect/plant or 2,000 insects/1,000m². Small spiders and released bugs are adults.
The results showed that the percentage of plants with powdery mildew when using small spiders and bugs was 4.35 - 4.58%. If using chemical drugs, this rate is from 3.2 to 3.6%, without using any measures, the percentage of plants with powdery mildew is 30-40%. In addition, the yield and quality of fruit when using these two types of natural enemies did not change compared to using chemical methods.
Currently, the research team has built a process (raising, releasing bugs and small spiders to catch prey), which can be transferred to individuals and organizations that need safe agricultural production.
ctngoc