|By goGreen | February 29, 2012|
Metarhizium anisopliae is a green muscardine fungus that attacks rice black bugs (RBB). It is a microbial control agent that is environment-friendly and easy to mass produce using locally available substrates. It is safe to humans and animals and is effective against the RBB. It is easy to apply and is compatible with other pest management components.
Metarhizium is prepared by mixing the palay and conidial suspension thoroughly and incubating it for 1-2 weeks.
One preparation of Metarhizium contains 2.5 trillion spores. Since the fungus can multiply by itself, one planting season requires only two to three applications, whereas five to six applications are required when chemical pesticides are used.
Metarhizium is also cheaper than chemical pesticides. A farmer would have to spend only P250 per hectare. Chemical pesticides, on the other hand, cost around P800 to P1,200 per hectare. Metarhizium is commonly applied through spraying, which should be done late in the afternoon because the active spores are killed by direct sunlight. Unlike chemical pesticides, it does not leave any residue on the crops that may be harmful to human health.
How to apply Metarhizium by spraying
1. Prepare conidial suspension by adding 200 ml of 0.05% soap solution (a mixture of 0.5 g all-purpose detergent and 1 liter water) to each bag of palay substrate.
2. Mix the fungal culture and soap/detergent solution thoroughly to dislodge the spores. Strain the suspension to remove the palay.
3. Place 1000 ml of the conidial suspension in the spray tank and bring the water level to 16 liters per tank load. Five bags containing 200 g palay substrate yields 1 L spore suspension. Fifty bags of palay substrates with the fungus are recommended per hectare. This contains approximately 1×1013 spores per hectare.
4. Spray early in the morning (around 6-8) or late in the afternoon (around 4-6).
5. Apply the formulation at the base of the plant to ensure contact between the fungus and the RBB.
6. Metarhizium-infected RBBs can be observed 4-7 days after application.
How to apply Metarhizium through irrigation water
1. Drain the field before application (usually in the early hours of the day of application).
2. Add 200 ml soap/detergent solution to Metarhizium cultures in plastic bags.
3. Mix the fungal cultures thoroughly.
4. Apply the fungus in the afternoon when most of the bugs have settled at the base of the plant.
5. Place the palay substrates with the fungus at the water inlets while water is conveyed onto the paddy.
6. Bring the water level to 6 cm.
7. Allow the water level to go down through natural evaporation until soil moisture is at saturation point.
8. Irrigate the field and maintain the normal water level to 2 cm.
Source: Open Academy for Philippine Agriculture