Plastic Covering Accelerates Phenological Stages and Causes Abiotic Stress in Table Grapes in Egypt

Abstract

Egypt, like other global countries, faces climate changes that threaten its economy and food security. Grape farmers and exporters protect grape vines from an unfavorable microclimate by using plastic covering (PC). This study assessed the impact of early plastic covering, from mid-January to the end of April, on the phenological stages, yield, and fruit quality of two seedless table grapes (Flame and Superior). Also, to find out if covering could cause additional stress on grape vines by assessing its effect on vegetative growth, chlorophyll content, and photosynthesis efficiency, as well as carbohydrates, proline, total phenols, lipid peroxidation, catalase, and ascorbate peroxidase content in leaves. Our research findings indicate that PC accelerates all phenological stages; additionally, it causes abiotic stress, leading to an increase in soluble sugar, total phenols, and proline content in vine leaves. Plastic covering did not affect most fruit quality parameters at harvest, such as cluster weight, small berries (%), TSS%, and titratable acidity (%). Nevertheless, PC reduced the anthocyanin content in Flame berries by 31.1% and 33.6% in the first and second seasons, respectively, compared to the uncovered group.In conclusion, PC could be recommended as a good strategy for combating climate change and hastening the harvesting of grapes. However, further research is needed to improve the pigmentation of grapes cultivated under plastic to provide an appealing appearance for consumers.