The effectiveness of some plant extracts and insecticides for control thrips (Thysanoptera : Thripidae) in pummelo cv. Tubtimsiam

Abstract

The main problems in pummelo qualitative production are thrips, that destroy young leaves, flowers and young fruits. The damage was found that fine leaf margins roll upward bend on both sides, brown marks leaves. If the outbreak occurs during young fruit stage, it may cause fruit-retarded, rough scarring on fruit surface. The efficiency of the different insecticides was done using neem and tobacco extracts, petroleum oil, the mix of these substances as an alternative treatments to replace synthetics insecticides. The experiment was conducted in 4-5 years old trees at Tubtimsiam pummelo plantation in Nakhon Si Thammarat Province. The result showed that the highest effectiveness was abamectin 98.67%, and followed by imidacloprid, petroleum oil mix tobacco, petroleum oil mix neem extract (azadirachtin 0.1%), neem extract (azadirachtin 0.1%), petroleum oil, tobacco and water spraying, was giving 95.54 89.53 88.14 86.14 84.56 77.19 and 76.69 % respectively, compared with non-treated control. The average percentage of leaf damage after application treatment at 7, 14 and 21 days were found that all treatments were significant differences from non-treated leaf damage.