Merfield, C. N.Hofmann, RainerHodge, S.Bennett, J.2021-06-152020-10-16https://hdl.handle.net/10182/13913Potatoes are the fourth-most important global food crop, but they suffer from a wide range of pests and diseases, including potato blight (Phytophthora infestans and Alternaria solani) and tomato potato psyllid (TPP, Bactericera cockerelli). Based on results from previous field trials of mesh crop covers to control TPP, two trials were conducted to study the impact of UV radiation on potato yield, TPP and blight. The first trial studied field-grown potatoes in cloches covered with either plastic or mesh covers each with contrasting UV transmission levels, and an uncovered control. Measurements included microclimate, visually assessed foliar blight & psyllid scores and crop yield. The second trial was a balanced 2 × 2 factorial design with pot-grown potatoes under A-frames with either UV-transmitting or UV-absorbing plastic sheets as one factor, and TPP-inoculated and TPP-free plants sprayed with insecticides as the second factor. Measurements included microclimate, crop yield, TPP and aphid populations. In the cloche trial, potato tuber weight and size increased compared to the control, with the largest increase under the UV-absorbing covers. Psyllid yellows and foliar blight symptoms showed strong correlation between UV radiation levels and damage symptoms, with the highest damage in the control, lower under UV transmitting covers, and the least under the UV-absorbing covers. In the A-frame trial there was no effect of TPP on yield, potentially due to low TPP populations, but a 1 kg per frame (23%) reduction of yield in plants exposed to near-ambient UV radiation. Psyllid yellows and counts were highest in plants exposed to TPP and near-ambient UV, and TPP counts were highest under the +UV+TPP treatment. In addition, there were no aphid counts under the UV-absorbing treatment. The results emphasise the value of using UV-absorbing covers as a highly effective and sustainable solution for pest control and increased crop productivity.53-53enConference Contribution - published