1. Assessing Losses in Rice Due to Insects and Diseases in Bangladesh
- Author
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Shamsul Alam, S. A. Miah, and H. D. Catling
- Subjects
business.industry ,Economic threshold ,Pest control ,Biology ,Monsoon ,biology.organism_classification ,Agronomy ,Midge ,Shoot ,Gall ,business ,Agronomy and Crop Science ,Cropping ,Sesamia inferens - Abstract
SUMMARYA series of 17 crop-loss assessments was made under simulated farmers' field conditions in the three main rice cropping seasons of Bangladesh. The main insect pests were the rice stem borers (Tryporyza incertulas, Chilo polychrysa, Sesamia inferens) and in the monsoon rice gall midge (Pachydiplosis oryzae). Disease incidence was negligible. In the winter and early monsoon yield losses averaged 4 and 6% respectively, but economic benefit was only derived from insecticide application in the monsoon season, when there was an average yield loss of 16%. An economic threshold of 5–10% damaged tillers (‘deadhearts’ and ‘onion shoots’) was indicated for early attacks of stem borers and gall midge. Possible reasons are given for the usually low incidence of insect pests and diseases in Bangladesh rice.
- Published
- 1978
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