REFLECTIVE GROUND COVERS INCREASE YIELDS OF TARGET FRUIT OF APPLE AND PEAR

Abstract

Reflective ground covers, such as Extenday ™ or Daybright ™ , increase the amount of light within the canopy available for photosynthesis, especially in the lower, shaded portions of tree canopies. These white woven polyethylene mulch cloths can be moved between crops in a single growing season and reused for up to ten years, thus reducing waste. Since 2005, the Washington Tree Fruit Research Commission (WTFRC), in collaboration with Extenday Ltd., has evaluated the horticultural effects of reflective ground covers in commercial Washington apple (Malus domestica) and pear (Pyrus communis) orchards. Extenday ™ and Daybright ™ have consistently improved fruit color and yields of desired fruit by increasing fruit set and/or harvest size; neither fruit set nor harvest size have ever been reduced relative to untreated controls. Fruit color development has frequently been advanced by these materials, enabling earlier harvests and in some cases, fewer picks. Yields have increased every year in Extenday ™ treated apple plots, suggesting a cumulative effect on increasing productivity. Aluminium-based ground covers such as Mylar ™ (1.75 m wide in the central alleyways) did not increase 'Gala' apple color as much as Extenday ™ , and had no effect on fruit size or yield. While initial capital costs for Extenday ™ products are relatively high, our results have shown consistent positive increases of production of target fruit suggesting a significant return on investment. These impacts are most clear in high density, well-managed systems.