The Effects of Reflective Film on Fruit Color, Quality, Canopy Light Distribution, and Profitability of ‘Mondial Gala’ Apples

Abstract

The effects of covering the orchard floor with Extenday™ or Solarmate™ reflective films on fruit color, fruit quality, canopy light distribution, orchard temperature, and profitability of ‘Mondial Gala’ apples (Malus ×domestica) were evaluated over a 3-year period (2000–02) at Lleida (northeastern Spain). Reflective film was laid down 5 weeks before commercial harvest. Photosynthetically active radiation in the lowest part of the tree (1 m aboveground level) increased by 34% and 56%, for Solarmate™ and Extenday™ films, respectively, compared with the control. Fruit color, measured with a portable tristimulus colorimeter, significantly increased on both sides of the fruit (with lower values of L* and hue) when using the film. A higher proportion of red blush over the fruit surface was observed for the fruit in the film treatments. Based on the fruit size and color required to meet European Union grade standards, the use of Extenday™ or Solarmate™ resulted in an increase of 26% and 17%, respectively, when compared with the control, for the number of fruit picked at first harvest. Season clearly affected fruit color development, whereas harvest date, fruit firmness, fruit size, soluble solid concentration, titratable acidity, and maturity were not consistently affected by the use of reflective film. Despite the advance in fruit color, the starch score did not appear to be affected by the use of film. Based on current fruit prices for the study period, both types of film increased orchard profitability compared with the control, but the long-term benefit of this technique will largely depend on fruit prices.