What are the usage and dosage of Bacillus thuringiensis?

Bacillus thuringiensis can be applied by two methods: spraying and broadcasting. Spraying involves starting application at the early stage of pest occurrence or the peak hatching period of eggs; generally, when used on vegetables, beans and sweet potato, 600-800 ml per mu is applied. Broadcasting is mainly used to control corn borer, applied at the whorl stage. Generally, 2000 units/mg granules are used at 300-400 g per mu.

How to use Bacillus thuringiensis:

1. Cruciferous vegetables: cabbage caterpillar, diamondback moth

Before the 3rd instar of larvae, use per 667 sq m 8000 IU/mg wettable powder 100-300 g, or 16000 IU/mg wettable powder 100-150 g, or 32000 IU/mg wettable powder 50-80 g, or 2000 IU/microliter suspension concentrate 200-300 ml, or 4000 IU/microliter suspension concentrate 100-150 ml, or 8000 IU/microliter suspension concentrate 50-75 ml, or 100 billion viable spores/g wettable powder 100-150 g, mixed with 30-45 kg of water for uniform spraying.

2. Rice: rice leaf roller, rice skipper

From the peak hatching period to before the 3rd instar of larvae, use per 667 sq m 8000 IU/mg wettable powder 300-400 g, or 16000 IU/mg wettable powder 150-200 g, or 32000 IU/mg wettable powder 80-100 g, or 2000 IU/microliter suspension concentrate 400-500 ml, or 4000 IU/microliter suspension concentrate 200-250 ml, or 8000 IU/microliter suspension concentrate 100-120 ml, mixed with 30-45 kg of water for uniform spraying.

3. Cotton: cotton bollworm, cotton geometrid

From the peak hatching period of larvae to before boring into bolls, use per 667 sq m 8000 IU/mg wettable powder 400-500 g, or 16000 IU/mg wettable powder 200-250 g, or 32000 IU/mg wettable powder 120 g, or 2000 IU/microliter suspension concentrate 400-500 ml, or 4000 IU/microliter suspension concentrate 200-250 ml, or 8000 IU/microliter suspension concentrate 100-120 ml, or 100 billion viable spores/g wettable powder 250-400 g, mixed with 45-75 kg of water for uniform spraying.

4. Corn, sorghum: corn borer

Use per 667 sq m 8000 IU/mg wettable powder 250-300 g, or 4000 IU/microliter suspension concentrate 150-200 ml, sprayed at the large whorl stage of corn or sorghum, or mixed with fine sand to make poisonous soil and poured into the whorl.

5. Soybean: soybean hawkmoth, sweet potato hawkmoth

At the peak hatching period of larvae, use per 667 sq m 8000 IU/mg wettable powder 200-300 g, or 16000 IU/mg wettable powder 100-150 g, or 32000 IU/mg wettable powder 50-80 g, or 2000 IU/microliter suspension concentrate 200-300 ml, or 4000 IU/microliter suspension concentrate 100-150 ml, or 8000 IU/microliter suspension concentrate 50-75 ml, mixed with 30-45 kg of water for uniform spraying.

6. Tobacco: tobacco budworm

Spray before the 3rd instar of larvae; use per 667 sq m 8000 IU/mg wettable powder 400-500 g, or 16000 IU/mg wettable powder 200-250 g, or 32000 IU/mg wettable powder 100-120 g, or 2000 IU/microliter suspension concentrate 400-500 ml, or 4000 IU/microliter suspension concentrate 200-250 ml, or 8000 IU/microliter suspension concentrate 100-120 ml, mixed with 30-45 kg of water for uniform spraying.

7. Tea plant: tea tussock moth

Spray from the peak hatching period to before the 3rd instar of larvae; use 8000 IU/mg wettable powder at 100-150 times dilution, or 16000 IU/mg wettable powder at 200-300 times dilution, or 32000 IU/mg wettable powder at 400-500 times dilution, or 2000 IU/microliter suspension concentrate at 80-100 times dilution, or 4000 IU/microliter suspension concentrate at 150-200 times dilution, or 8000 IU/microliter suspension concentrate at 300-400 times dilution, or 100 billion viable spores/g wettable powder at 200 times dilution for uniform spraying.

For jujube looper, start spraying before the 3rd instar of larvae; the dilution is the same as for “tea tussock moth”. For citrus swallowtail, start spraying at the peak hatching period of larvae; the dilution is the same as for “tea tussock moth”. Apple ermine moth, pear tent caterpillar

Start spraying at the peak hatching period of larvae; the dilution is the same as for “tea tussock moth”. For forest looper, tussock moth, pine caterpillar and fall webworm, start spraying at the early stage of pest occurrence; the dilution is the same as for “tea tussock moth”.

In addition, the editor reminds that Bacillus thuringiensis must not be mixed with systemic organophosphorus insecticides or fungicides or Bordeaux mixture. This agent is highly toxic to silkworms, so a certain distance must be maintained between silkworm-rearing areas and application areas.