Effects of shading and insect-proof screens on crop microclimate and production: A review of recent advances

Shading and insect-proof screens are widely used in agriculture for passive microclimate control and for insect exclusion. It is an efficient tool for crop production in adverse climatic and environmental condition. As screens are made of a porous material, the protected environment usually interacts with the outside and hence screens provide only moderate microclimatic modifications. Nevertheless, such modifications might be crucial for certain horticultural processes, thus may strongly influence production and quality. Depending on the type of screen, structure configuration, crop and climatic region, recent studies have shown that compared to open field conditions, screens reduce solar radiation and air velocity by about 15-39% and 50-87%, respectively; increase air relative humidity by 2-21%; decrease air temperature and evapotranspiration by 2.3-2.5 °C and 17.4-50% respectively. This paper seeks to review recent advances regarding effects of such screens on microclimate, crop water use and production. Therefore, the ultimate objective of this review is to assist both researchers and growers. For researchers the review provides up-to-date information of the recent studies as well as knowledge gaps that call for future research. For growers and extension service experts this review would assist in choosing the appropriate screen for a specific application, based on the current knowledge.