How to use BT insecticide on vegetables
The newspaper published a method for killing pests with BT insecticide. Many vegetable growers called in, some asking how to use BT insecticide, and others discussing with the reporter their experience of using BT insecticide in vegetable production. The reporter put together the insights of the vegetable growers who called in. BT insecticide, that is, Bacillus thuringiensis microbial...
The newspaper published a method for killing pests with BT insecticide. Many vegetable growers called in, some asking how to use BT insecticide, and others discussing with the reporter their experience of using BT insecticide in vegetable production. The reporter put together the insights of the vegetable growers who called in.
BT insecticide, namely Bacillus thuringiensis microbial insecticide, contains parasporal crystals and spore toxins that poison pests. It kills pests well, and resistance is relatively difficult to develop during use. However, in practical application, because the method is not mastered, the results are less than satisfactory. To improve the control effect of BT insecticide, the following requirements must be mastered:
First, master a reasonable application concentration. Because the types of pests in the greenhouse differ, their sensitivity to BT insecticide also differs, so the application concentration is not the same. Only by choosing a suitable concentration according to the sensitivity of the pest can a good control effect be achieved. For imported cabbageworm, a 500-1000 times dilution can be used.
Second, determine a suitable application time. The efficacy of BT insecticide is slower than that of chemical insecticides, so the application time should be 2-3 days earlier than that of chemical insecticides, and application from the peak hatching period to the 1st-instar larval stage gives the best effect.
Third, when spraying, also pay attention to temperature. Under strong light and at temperatures above 25°C, application at around 5 p.m. is preferable. When applying, spray the front and back of the leaves thoroughly to improve efficacy.
In addition, to improve the control effect of the pesticide, especially when pests break out heavily, it can be mixed with a variety of insecticides, but it must absolutely not be mixed with fungicides.