Field evaluation of plant leaf extracts, oil and neem products against mango hopper (Amritodus atikinsoni Lethierry) and thrips (Scirtothrips mangiferae Hood).
Kumar S., Bhatt R. I.
Author Affiliation: Agriculture Experimental Station, Gujarat Agricultural University, Paria-496 145, Valsad, Gujarat, India.
Allelopathy Journal 6 : 271-276
Abstract : Field trials were conducted at Paria, Gujarat, India, during 1995-97 to assess the effects of 3 applications of 2.5% aqueous extracts of dried leaves of Azadirachta indica, Gliricidia mutica and Ipomoea carnea, 4 commercial neem (A. indica) products (0.5% Achook, 0.5% Neemark, 1% Indiara and 0.2% Azadex) and 3 plant oils (0.1% mint oil, 2% atso tree oil and 2% savo spray oil) on control of Amritodus atkinsoni and Scirtothrips mangiferae, and compared with results achieved with a combination of 0.003% cypermethrin, 0.07% endosulfan and 0.04% monocrotophos. Results indicated that all treatments significantly reduced A. atkinsoni. Best results were achieved with synthetic insecticides, but these were not significantly better than those achieved with the commercial neem products and leaf extracts of I. carnea and A. indica. The synthetic insecticides also gave best control of S. mangiferae, but these were not significantly different to those achieved with Nemark, Achook and G. mutica extract, with the other 2 leaf extracts and Azadex giving next-best control. Oil treatments were ineffective against both pests. Fruit bearing was better in trees treated with synthetic insecticides, but the botanical insecticides reduced fruit drop as well as the synthetic treatments. Best yields were produced by the synthetic insecticide treatment (72.9 kg/tree) followed by Neemark (41.3 kg), Indiara (37.0 kg) and Achook (35.8 kg).