scholarly journals Avaliação de inseticidas para o controle de Thrips tabaci (Lindeman, 1889) (Thysanoptera: Thripidae) em campo, na cultura da cebola

2019 ◽  
Vol 1 ◽  
pp. ec01011
Author(s):  
Leandro D. Geremias ◽  
Paulo Antônio de S. Gonçalves ◽  
Renata S. Resende

The efficacy of 14 different insecticides was tested for the control of onion thrips Thrips tabaci (Lindeman, 1889) on onion in Itajaí Valley, SC during 2018. The insecticides were sprayed six times at intervals of about seven days, we evaluated the number of nymph of thrips per plant 48 hours after spray, visually rated for thrips damage at 96 DAT and total and commercial onion bulb production. Significant diferences were observed between various insecticides evaluated. The treatments formetanate hydrochloride, spinetoram and abamectin proved the best thrips control, less thrips damage and good total and commercial productivity. The insecticide profenofos + cypermethrin exhibited reduction of thrips nymph and better total and comercial production comparing control however not reduced thrips damages. The insecticides thiacloprid, thiamethoxam + lambda-cyhalotrin, and Imidacloprid reduced the thrips density but had similar results for thrips damages and onion bulb production comparing with control, excepting total productivity for the neonicotinoids thiacloprid and and Imidacloprid.

2018 ◽  
Vol 87 (2) ◽  
pp. 165-176
Author(s):  
Muhammad Asghar ◽  
Mirza Muhammad Qadeer Baig ◽  
Muhammad Afzal ◽  
Naeem Faisal

Abstract The efficacy of five insecticides containing a.i. bifenthrin, dimethoate, spinosad, spinetoram and chlorfenapyr was evaluated following RCBD against Thrips tabaci in farmer’s field for two consecutive years. The data were recorded before and after 24 h, 48 h, 72 h and 7 days of spraying. The results showed that all the insecticides reduced thrips populations compared to controls. However, the maximum reduction in thrips population and highest onion bulb yield (34.07 t/ha) was obtained with dimethoate 40EC followed by bifenthrin 10EC (33.14 t/ha). The minimum onion bulb yield (25.71 t/ha) was obtained in the control, where no insecticide was applied against thrips. If onion thrips are not controlled, the damage they cause can reduce bulb yields by 9-25%. The highest incremental return over the control (Rs.83, 600/ha), net income (Rs.82, 913/ha) and maximum cost benefit ratio were also obtained in the treatment with dimethoate 40EC.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 506d-506
Author(s):  
Robert R. Tripepi ◽  
Holly J. Schwager ◽  
Mary W. George ◽  
Joseph P. McCaffrey

Two insecticides, acephate or azadirachtin, were added to tissue culture media to determine their effectiveness in controlling onion thrips (Thrips tabaci Lindeman.) and to determine if these insecticides could damage the plant shoot cultures. To test for insecticide phytotoxicity, microshoots from European birch (Betula pendula), American elm (Ulmus americana), `Pink Arola' chrysanthemum (Dendranthema grandiflora), `America' rhododendron (Rhododendron catawbiense), `Golden Emblem' rose (Rosa hybrida), and `Gala' apple (Malus domestica) were placed in 130-ml baby food jars containing 25 ml of medium supplemented with 6.5, 13, or 26 mg/l Orthene® (contained acephate) or 0.55, 1.1, or 2.2 ml/l Azatin® (contained azadirachtin). Control jars lacked insecticide. To test for thrips control, 13 mg/l Orthene® or 0.55 ml/l Azatin® was added to Murashige and Skoog medium, and 10 thrips were placed on `Gala' apple microshoots in each jar. Jars were sealed with plastic wrap. In both studies, microshoot dry weight and heights were determined. In the second study, the total number of thrips per jar was also determined 3 weeks after inoculation. Microshoots on Orthene®-treated media lacked phytotoxicity symptoms, regardless of the concentration used. In contrast, Azatin® hindered plant growth, decreasing shoot height or dry weight by up to 85% depending on the species. Both insecticides prevented thrips populations from increasing, since less than 10 thrips were found in jars with insecticide-treated medium. Control jars, however, contained an average of almost 70 thrips per jar. This study demonstrated that both Orthene® and Azatin® were effective for eradicating thrips from plant tissue cultures, but Orthene® should probably be used because Azatin® was phytotoxic to all species tested.


2021 ◽  
Vol 83 (1) ◽  
pp. 21-24
Author(s):  
V Karuppaiah ◽  
S J Gawande ◽  
V Mahajan ◽  
M Singh

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