Field evaluation of spinetoram 12 SC against Maruca vitrata on pigeonpea

Abstract

The acute and persistent toxicity experiments was conducted in the Insectary of Agricultural College and Research Institute (ACandRI), Maduari, Tamil Nadu Agricultural University. Two field experiments were conducted at farmer’s field at Jadhi Goundanpatti, Attur Block, Dindigul district, Tamil Nadu. The incidence of M. vitrata (Geyer) has been increasing for the last few years and the larvae bore inside the flower buds, flowers and the green pods and cause upto 40-70 per cent damage. A new biological insecticide molecule, spinetoram 12 SC was evaluated for acute toxicity on laboratory reared M. vitrata population, and persistence on pigeonpea leaves at laboratory conditions; and effect on M. vitrata on pigeonpea at field conditions during 2012-13 and 2013-2014 seasons. Acute toxicity studies revealed that LC50‘s of spinetoram on third instar larvae after 24, 48 and 72 hours after treatment were 4.30, 1.95 and 1.46 ppm respectively. In persistence studies, Persistence was upto 11 DAT for spinetoram 12 SC 27 g a.i./ha, spinosad 45 SC 78 g, emamectin benzoate 5 SG at 11 g a.i./ha, and monocrotophos 36 SL at 500 g; and 14 DAT for spinetoram 12 SC 36 and 45 g a.i./ha. There was a reduction in the mortality of M. vitrata larvae as the time increased and there was no mortality at 21 DAT. Results indicated that spinetoram 12 SC was significantly effective at 36 and 45 g a.i./ha when sprayed thrice at 15 days interval and minimized the incidence of leaf feeder, M. vitrata on pigeonpea plants.

Seasonal Abundance of Spotted Pod Borer, Maruca vitrata Fabricius in Early Pigeonpea [Cajanus cajan (L.) Millsp.] and its Management through Farmscaping in Uttar Pradesh

“…Singh (1999) has reported a yield loss of 70-80 per cent in pigeonpea at Bangalore, India. A similar loss in pigeonpea was also reported from Dindigul, Tamil Nadu also (Kumar and Pavviya, 2018). Short duration pigeonpea recorded higher pod damage by M. vitrata (32%) than gram pod borer, Helicoverpa armigera (Hubner) Hardwick (4%), pod bugs and blister beetle in Uttar Pradesh (Sujayanand and Saxena, 2013).…”

Evaluation of Biorational Insecticides Against Pigeonpea Pod Borer

“…Comparably, the next best was emamectin benzoate 5SG @ 0.3 g/ l, with 86.93 and 90.89% reduction in larval incidence, and also recorded 62.52 and 62.63% reduction in pod infestation with 76.38 and 75.49% increase in yield; and with C:B ratio of 1:9.80 and 1:10.34 during 2016 and 2017, respectively. The results obtained from the present study is in conformity with the findings of Bairwa and Singh (2015), Singh and Singh (2017) and Kumar and Pavviya (2018), who reported that the spinosad followed by emamectin benzoate was most effective in reducing the larvae of M. vitrata. These findings also corroborate with those of Randhawa and Saini (2015) on spinosad 45SC.…”

Effect of Planting Dates and Certain Insecticides on the Lima Bean Pod Borer, Etiella zinckenella (Treit.) (Lepidoptera: Pyralidae) and Productivity of Cowpea Plants in Qalyoubia Governorate.

“…Similarly Kumar et al (2014) indicated that Spinetoram 12% SC was significantly effective in minimizing E. zinckenella larval population on pigeonpea plants and increasing the grain yield. Dhaka et al (2011) showed that Spinosad, B. thuringiensis and Neemarin, was recorded the best yield comparable untreated control against E. zinckenella larval.…”

“…Spinosad) gave 66.7% mortality of S. littoralis larvae. Kumar et al (2014) indicated that Spinetoram 12% SC was significantly effective when sprayed three time at 15 days interval in minimizing E. zinckenella larvae populations on pigeonpea plants and increasing the grain yield.…”