Pesticides and rice production

• Last Updated Tuesday, 10 November 2009 01:23

Sustainable pest management is an important part of rice production systems as pests affect the yield and quality of rice. To help farmers with pest management IRRI develops pest- and disease- resistant varieties of rice, integrated pest management (IPM) strategies, and ecological engineering approaches.

Rice varieties with built-in pest and disease resistance

IRRI has been instrumental in developing rice varieties with built-in resistance to common pests and diseases, including brown planthoppers, stem borers, green leafhoppers, tungro virus, blast, and bacterial blight. All IRRI-bred varieties are screened before release to ensure they have a base level of resistance to these pests and diseases. New rice varieties are also tested in pest and disease “hot-spots” to check their performance under pest and disease pressure before release so that no vulnerable varieties are distributed to farmers.

IRRI is also searching for new resistance genes to improve rice’s built-in resistance to existing and emerging pest and disease threats. Because of their built-in pest and disease resistance, IRRI pest-resistant varieties typically require less pesticide than susceptible varieties.  

Smarter pest management through integrated pest management

IRRI has had significant success in reducing pesticide use by researching and promoting integrated pest management (IPM) that, through a smarter understanding of pest dynamics, uses a variety of different strategies to minimize pest damage while eliminating or reducing pesticide use. IPM encourages farmers to manage pests through the use of pest-resistant varieties, to observe the activity of pests and natural enemies, to understand the difference between when pest levels are a problem and when they are acceptable, and to decide whether action is needed. Chemicals are used only as a last resort and their application is aimed at maximizing natural biological control.

In Vietnam, IRRI’s award-winning Ba Giam, Ba Tang (or Three Reductions, Three Gains) project used a radio drama, a television drama, a 30-second TV commercial, posters, flyers, and extension efforts to promote reductions in unnecessary and costly inputs into rice production – including pesticides. As a result, insecticide sprays declined 13–33%, seed and fertilizer rates dropped, and farmers’ beliefs about the value of high inputs changed. The reduced inputs resulted in similar or higher yields and net incomes, and the health of farmers and the environment also improved.

IRRI has also initiated a multimedia campaign in Vietnam and Thailand called No early spray. This was aimed at motivating farmers to reduce insecticide applications in the first 40 days of the crop and has reduced farmer application of insecticide sprays in Vietnam by 53% and in Thailand by 22%.

Working with the natural ecosystem to fight pests

IRRI has just initiated a project to develop ecological engineering methods to restore or reinforce natural enemy biodiversity and valuable ecosystem services in intensive rice production areas to reduce vulnerability to pest invasions. Underway in China, Malaysia, Thailand, and Vietnam, this project is developing methods to increase beneficial plants, such as flowers, along bunds (the ridges between rice fields) to provide food resources for natural enemies. 

Better pest management in IRRI’s own backyard

On IRRI’s own research farm in the Philippines we have adopted IPM and between 1993 and 2008 we reduced insecticide use by 96%. We are now enjoying rather pest free conditions and clear restoration of natural enemy biodiversity and ecosystem services.