[Control of the tomato fruitworm (Heliothis armigera Hb.) at different infestation levels in People's Democratic Republic of Yemen]
1986
Ba-Angood, S.A. (J"a:mi3at 3adan (Yemen, D.). Kiliyyat na:s*ir lil-3ulu:m al-zira:3iyyat) | Hubaishan, M.A.
Tomatoes in PDR of Yemen are subject to attack by the tomato fruit worm, Heliothis armigera Hb. which is controlled chemically by applying different insecticides mainly carbaryl and tetrachlorvinphos when the percentage of infested fruits reached 10%. The results of three-year field experiments 1980/81, 1981/82 and 1982/83 showed that there was a significant difference in the reduction of percentage of infested fruits and in the increase of yield of tom1328atoes in treatments that received two sprays of tetrachlorvinphos when the percentage of infested fruits was 10% and those which received only one spray when the percentage of infested fruits reached 15%, compared with other spray treatments at 20% and no-spray treatments. When the cost of chemical control operation was taken into consideration, it was found that one spray at 15% fruit infestation was more economical than two sprays at 10% infesta
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