OPTIMAL TIME FOR INSECTICIDE APPLICATIONS TO REDUCE THE ONION THRIPS, Thrips tabaci POPULATION ON GARLIC CROP AND THEIR EFFECT ON RESULTANT YIELD.

Abstract

An experiment was carried out under field conditions at Ziton village in Beni-Sueif Governorate during two successive seasons, 2011-2012 and 2012-2013 to choose the suitable time of insecticide applications and their effect on T. tabaci infestation on garlic plants and resultant yield. The four tested treatments by applying two recommended insecticides at different times of plant growth were Carbosulfan (Marshal 20% EC with recommended rate 200 cm 3 / fed.) and Spinetoram (Radiant 12% SC with recommended rate 120 cm 3 / fed) compared with the untreated garlic plants. Results and their statistical analysis showed clearly that all treatments significantly decreased the population density of T. tabaci and increased the garlic yield comparing with control treatment. The applying of Carbosulfan and Spinetoram at 15 day intervals (12 times of applications) throughout the whole growing season of garlic plant till one month before harvesting (T1) lead to reduce the population density of T. tabaci infesting garlic plants and gave the highest yield in the two studied seasons, as an average head weight of 12463.50 kg / feddan. Although, garlic plants which treated by Carbosulfan and Spinetoram after one month of sowing date from Nov., 1 st at 30 old days till Dec., 15 th (4 times of applications) (T2) infested by higher number of T. tabaci,then gave the considerable head yield (9313.50 kg / feddan). However the application of T3 (Spraying of Carbosulfan and Spinetoram from Jan., 1 st of at 90 old days till Feb., 15 th) and T4 (spraying of Carbosulfan and Spinetoram from March 1 st at 150 old days till April, 15 th) (4 times of applications) were the lowest infested group of T.tabaci and gave the lowest yield in the 4 insecticide applications, as the average of garlic head weight in the two seasons were 8498.70 and 8333.85 kg / feddan respectively. On the other hand, garlic plants in control plots infested by the significantly highest number of T. tabaci and gave the lowest yield when compared with the fourth treatment, as the average head weight in the two seasons was 6139.35 kg / feddan. Concerning the net return of the all tested treatments, T1 gave the best return 13322.55 L.E / feddan.

Evaluation of different insecticides for the management of onion thrips (Thrips tabaci Lindeman, 1889) (Thysanoptera, Thripidae) on onion (Allium cepa L.) crops

“…Except for Actara, all the other insecticides were significantly effective against the pest as compared to the control. The results of the present investigation are also in agreement with those of HUSSEIN et al (2015), who found in two study seasons that application of carbosulfan 20EC and spinetoram 120SC reduces the population density of T. tabaci infesting garlic plants and gave the highest yield.…”

“…Therefore, in the present study the control plot gave a minimum yield. The results are also partially in agreement with those of HUSSEIN et al (2015), who obtained the highest yield of garlic with the application of carbosulfan 20EC and spinetoram 120SC against onion thrips. PATIL et al (2009) found that treatment with deltamethrin 1EC+triazophos 35EC recorded a higher yield t/ha, which was statistically on a par with spinosad 45SC compared to the other treatments.…”

Management of Onion Thrips <i>Thrips Tabaci</i> Lindeman

“…Shelton et al (2008) showed that acetamiprid, dimethoate, spinosad and imidacloprid performed better than lambda-cyhalothrin against thrips on cabbage. Dimethoate proved to be the best against thrips followed by bifenthrin 10 EC (Muhammad et al, 2018); and application of carbosulfan 20EC and spinetoram 120SC greatly reduced the T. tabaci infesting garlic and increased the bulb yield (Hussein et al, 2015). Significantly higher bulb yield with high returns was achieved with application of Rynaxypyr 20 SC @ 0.15 ml/ l followed by spinosad 48SC @ 0.12 ml/ l (Sreenivas et al, 2013).…”

Bioefficacy, phytotoxicity and safety of Virtako 1.5 Gr a premixed commercial insecticide against thrips, black cutworm and natural enemies in onion

“…Among these, onion thrips Thrips tabaci Lindeman (Thysanoptera: Thripidae) is a major pest of national significance (Gupta et al, 1991) and black cutworm, Agrotis ipsilon Hufnagel (Lepidoptera: Noctuidae) being a pest of regional importance in India (Satyagopal et al, 2014). The estimated yield losses due to insect pests and disease in onion are up to 10-15% (Gupta et al, 1994) Thrips causes curling and blistering white patches on the leaves, leads to reduced photosynthesis, ultimately resulting in the formation of undersized bulbs (Hussein et al, 2015) and also aggravates fungal disease such as purple blotch and act as a vector of Irish Yellow Spot Virus (IYSV) in onion (Arantha, 1980;Pozzer et al, 1999). Black cutworm, A. ipsilon is a defoliator pest attacking onion, and the early instar larva damages the tender foliage of young seedlings whereas the late instar completely cuts through the stalks causing plant death (Capinera, 2001).…”