Postharvest 1 Physiological Disorders in Table Grapes

Abstract

Marketability of fresh table grapes is dependent on several quality attributes 53 such as good flavor, appearance and texture, and absence of defects. A large number of 54 physiological disorders can occur during postharvest of table grapes affecting their 55 overall quality and hence, causing considerable economic losses. The most frequent 56 disorders affecting the berry include failure in color development in red varieties, berry 57 shattering or drop, softening, bunchstem necrosis (waterberry) and damage associated to 58 sulfur dioxide application to control gray mold. The susceptibility of table grapes to 59 develop these disorders varies greatly among varieties. Most disorders found in the 60 berry are determined largely by preharvest factors such as environmental conditions, 61 cultural practices and crop management. On the other hand, postharvest handling and 62 management play a critical role in determining the severity of the disorder, especially 63 when grapes are subjected to long periods of storage and transport until reaching the 64 market. Water loss is the main abiotic factor that produces postharvest deterioration of 65 table grapes, particularly in the stem or rachis. Dehydration of the stem results in tissue 66 browning, a disorder that alters table grape appearance leading to consumer rejection. In 67 this chapter, in-depth descriptions of the main physiological disorders affecting the 68 berry and the stem during postharvest of table grapes, as well as their possible causes 69 are provided. In addition, pre- and postharvest approaches that could reduce the 70 incidence and severity of these disorders are reviewed and discussed.