Viral diseases control with UV-blocking films in greenhouses of southern Spain

The UV radiation is the most important factor for the degradation of agricultural films; therefore it is usual to include in their formulation UV absorbers as stabilizers. However, the usual amount is not enough when specific effects are pursued. We have been exploring the use of films especially opaque to UV radiation as an ecological alternative against specific pathogens of greenhouse crops. The films that act in this region are those which are known as antipest films (antibotrytis, antivirus, antiinsects) and affect the development of pests or diseases caused by fungi or viruses transmitted by insects which are affected by the decrease or absence of this type of radiation. An increasing demand of tri-layer films has been observed over a for three agricultural seasons duration. Due to currently existing formulations it is not possible to reach an antipest effect for three agricultural seasons with monolayer films. Therefore, we field tested the new tri-layer formulations developed by Repsol YPF in real conditions, to determine UV opacity of films, the antipest effectiveness, and the influence on the performance of the pollinator insects. Improved duration of the UV blocking effect occurred with the new filters used. In most cases, the yield obtained with UV-blocking films is higher than with normal films.