Measuring the effect of non-crop flowering plants on natural enemies in organic tobacco

摘要

The use of "insectary strips" of sunflowers and buckwheat is widely promoted by organic certifiers to promote control of the green peach aphid (Myzus persicae) and other pests in organic tobacco. However, no published research supports this recommendation in tobacco, and results from other crops are mixed. We performed a series of experiments to test the effects of non-crop plantings of sunflowers and buckwheat on key pest and beneficial insects adjacent to organic tobacco fields in North Carolina. Although some reduction in M. persicae infestations and increases in numbers of beneficial insects were observed on tobacco plants near field-edge insectary treatments, these effects were small and were observed only over a short distance into the crop. Planting additional insectary strips in the field interior did not reduce aphid numbers in comparison to control treatments and led to increases in some pest insects. These conservation biological control techniques are unlikely to be a reliable method of controlling M. persicae and other pest insects in organic tobacco.