A commercial extract of the brown seaweed Ascophyllum nodosum suppresses avocado thrips and persea mites in field-grown 'Hass' avocados, a practical field perspective.

摘要

Thrips cause damage to vegetables, fruits, and flowers and are found worldwide. They directly damage crops by feeding, vectoring viruses, and may also cause respiratory and skin irritation to field workers. Effectively managing thrips and mites with non-toxic materials has proven to be one of the most challenging aspects of pest control. A commercial extract from the brown seaweed Ascophyllum nodosum, reduced avocado thrips (Scirtothrips perseae) numbers by 68% compared to the control, in field-grown 'Hass' avocado trees. This reduction in thrips number was not significantly different from reduction due to abamectin treatment; the most common chemical control for thrips in avocados. In addition, there were 87% fewer colonies of Persea mites (Oligonychus perseae) per leaf in the A. nodosum extract (ANE)-treated trees compared to the control and the ANE-treatment was not significantly different from the abamectin standard. The following year there was no thrips pressure due to environmental conditions, however, ANE extract again reduced Persea mite colonies compared to the control. ANE extract applications resulted in significantly fewer thrips nymphs and Persea mite colonies on avocados under light pest pressure.