EFFECT OF PLASTIC FILMS ON DAY-NEUTRAL STRAWBERRY YIELDS
All the plastic films except treated polyethylene exerted a positive control on heat thermal efficiency. Radiant energy levels were not different among the tunnels in regard to their spectral transmission characteristics. Tunnel films did reduce light intensity. The tunnels had diverse effects on the yields of the two tested cultivars: Brighton was more affected than Fern. The most effectie for both bearing earliness and cropping were EVA, EVA triple layer and EVA subtended with treated polyethylene. These films advanced the spring crop by one week and extended the autumn one, thereby increasing total yield. Both tunnel-grown cultivars showed increased yieldsin comparison to open-field cultivation.