| dc.description.abstract | Tomato is one of the most popular solanaceous vegetable crops. It is attracted by a large
number of sucking insect pests like aphid, jassid, thrips, white fly etc. Thrips is one of
the most common pests of tomato which is severely responsible for plant growth, crop
quality and yield. The insect pest control by chemical insecticides is yet considered as
most effective. Relative toxicity of seven selected insecticides (abamectin 1.8 EC,
imidacloprid 70 WG, bifenthrin 2.5 EC, deltamethrin 2.5 EC, lambda-cyhalothrin 2.5
EC, spinosad 2.5 SC and thiamethoxam 25 WG) along with untreated control were
evaluated to Frankliniella schultzei thrips (Thysanoptera: Thripidae) infesting tomato
(BARI TOMATO 4). The effectiveness of treatments was evaluated by two consecutive
sprays following randomized complete block design (RCBD) with three replications.
Data were recorded at 1, 3, 5, 7 and 14 days after spray (DAS) in each case. After two
sprays, among seven insecticides imidacloprid reduced the highest thrips population on
leaf (75.73%) followed by thiamethoxam (66.96%) spinosad (61.83%), abamectin
(59.34%), lambda-cyhalothrin (54.89%), deltamethrin (52.57%), and bifenthrin
(41.90%). In case of flower infestation, the highest reduction of thrips was 77.22%
(imidacloprid) followed by 70.77% (thiamethoxam), 64.89% (spinosad), 61.43%
(abamectin) 60.27% (lambda-cyhalothrin), 56.20% (deltamethrin), and 53.21%
(bifenthrin) compared to untreated control after second spray. Considering the yield of
tomato and economics of cultivation, the highest yield (11 kg/plot) was found from
imidacloprid treated plot followed by thiamethoxam (9.33 kg/plot), abamectin (8.33
kg/plot), spinosad (8 kg/plot), lambda-cyhalothrin (7.67 kg/plot), deltamethrin (7 kg/plot)
and bifenthrin (6.67 kg/plot) treated plot, as compared to untreated control (6 kg/plot).
However, from the benefit cost ratio (BCR) the highest BCR (5.79) was recorded in
imidacloprid and the lowest was found in bifenthrin (3.61) treated plot. Thus, among the
treated insecticides, imidacloprid was the most effective in reducing Frankliniella
schultzei and for getting the highest yield and BCR in comparison with other
insecticides. So, tomato growers can use imidacloprid as a chemical control against
Frankliniella schultzei. | en_US |
