17 research outputs found

    In vitro Assessment of Neonicotinoids and Pyrethroids against Tea Mosquito Bug, Helopeltis antonii Sign. (Hemiptera: Miridae) on Guava

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    The tea mosquito bug (TMB), Helopeltis antonii, is an emerging pest of horticultural crops, specially on guava and moringa. Insecticides are indispensable component for the management of insect pests. Exploration of new molecules with shortest waiting period may pave way for managing TMB in fruit and vegetable crops with nil/low residue. Until now there are no recommended insecticides available under Central Insecticides Board & Registration Committee (CIB&RC) against TMB on guava. In view of the above facts, new molecules with a low waiting period and are recommended by CIB&RC on tea, viz., Clothianidin 50% WDG, Thiacloprid 21.7% SC, Bifenthrin 10% EC, and Thiamethoxam 12.60% + Lambda-Cyhalothrin 9.5% ZC, were chosen and evaluated against TMB under in vitro condition. Clothianidin 50% WDG recorded the highest mortality of 100.00 per cent at 72 hours after treatment (HAT), and the lowest LC50 value (0.328 ppm, fiducial limits: 0.144-0.515 ppm) and LT50 value (10.49 h, fiducial limits: 5.444-14.551 h), followed by Thiamethoxam 12.60% + Lambda-Cyhalothrin 9.5% ZC, Thiacloprid 21.7% SC, and Bifenthrin 10% EC. The results showed that the Clothianidin 50% WDG and Thiamethoxam 12.60% + Lambda-Cyhalothrin 9.5% ZC, were highly effective, with the lowest LC50 and LT50 values. Since TMB occurs from new flushing to fruiting stage of guava, a minimum of two sprays are mandatory to have quality fruit yield. Hence, application of Clothianidin 50% WDG followed by Thiamethoxam 12.60% + Lambda-Cyhalothrin 9.5% ZC on need basis will help to reduce the impact of TMB on guava

    Reconstructing Chola Agrarian History: Parvathi Menon Interviews Y. Subbarayalu

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    In the interview, Subbarayalu draws on inscriptions, the primary source material of this period, to discuss aspects of the agrarian history of Tamil Nadu, and particularly of the Cauvery delta, between 900 and 1279 CE. A great deal of what we know of modern Tamil Nadu’s ancient and medieval past, including its economic and agrarian history, lies inscribed on the walls of the numerous temples of South India. Subbarayalu discusses inscriptions as a historical source, the difficulties encountered in deciphering them and in drawing evidence-based conclusions from what they offer. The Epigraphy section of the Archeological Survey of India in Mysore holds nearly 50,000 inscriptions in the four south Indian languages. Of these, the Tamil inscriptions number 27,000, out of which only 11,000 have been published in properly edited volumes. Much history remains to be written from these, particularly the history of the Vijayanagar period
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