Residual effects of Spray Adjuvant, Scorch®, on efficacy of Methoxyfenozide (SC 24%) and Spinosad (SC 24%) against the European Grapevine Moth, Lobesia botrana

The results of field trials conducted to evaluate the influence of an adjuvant, Scorch^®, on the field efficacy of methoxyfenozide (SC24%) and spinosad (SC24%) against Lobesia botrana in Iran, are reported. Efficacy was evaluated 1 d after treatment (DAT) and then at 7d interval until 21 DAT. Scorch^® was able to improve the efficacy of both the insecticides against L. botrana at all DAT intervals. The higher efficacy was supported by the lower values of the surface tension and the contact angle parameters of the spray solutions. By reducing the insecticides application rates by 20 per cent and adding adjuvant in the spraying liquid, the control efficiency was very similar to that of the treatment with the recommended rates. The results underscore the importance of adjuvants to improve the field efficacy of insecticides against L. botrana.