Effect of Different Shading Practices Used at Pre-harvest Stage on Quality and Storage Life of Sultana Seedless Grapes

Covering the grapevine rows to delay maturity and thus the harvest date becomes a widespread practice at Sultana seedless vineyards. The research work was carried out with different covers to examine their effects on grape quality and storage life in 2009 and 2010. Grapevines were covered with three different densities （shading ratios： 35%, 55%, 75%） at the veraison period. Unshaded （0%） control grapevines and grapevines shaded under different ratios were covered with polypropylene cross-stitch just before harvest maturity. Grapes under cover were harvested nearly one month after than those maturing under open conditions. Grape clusters were packed in PE bags and pre-cooled after harvest and then SO2-generating pads has been put on top, bags were sealed. In the second year at the 120th day of the storage, decay development has been observed in all applications. Total soluble solids content, maturity index and a＊ colour value were found lower in 55% and 75% shaded grapes compared to unshaded grapevines. Still,