Land productivity, irrigation water use efficiency and fruit quality under various plastic mulch colors and irrigation regimes of strawberry in the eastern Mediterranean region of Turkey

This experiment was conducted to evaluate the effects of irrigation regimes and three types of plastic mulches on the land productivity, irrigation water use efficiency (IWUE), leaf area index (LAI), growth parameters (crown number, crown diameter and dry matter) and quality of drip-irrigated strawberries. It was conducted on cv. Fortuna strawberries grown in a high tunnel during the 2016-2017 growth season in the Eastern Mediterranean region of Turkey using a split-plot design with four replicates. The treatments comprised full irrigation (Ir100) and deficit irrigation (Ir50) in combination with three mulches, namely silver on black (S), black (B) and transparent (T) and no mulch (N). A higher soil moisture content was found under the S mulch, followed by B, T and N, throughout the entire crop growth period for both irrigation regimes. The greatest land productivity was obtained from the SIr100 (71.9 t ha(-1)) application, followed by BIr100 (59.4 t ha(-1)), TIr100 (52.1 t ha(-1)) and NIr100 (51.5 t ha(-1)). The IWUE, LAI and growth parameters reflected the same trend as the land productivity, which could be attributed to the soil water content of the mulches. Under the Ir50 irrigation regime, all of the parameters were significantly decreased, except for the IWUE. Furthermore, in spite of the extensive use of B mulch in Turkey's Mediterranean region, the performance of S mulch was mostly superior in terms of the accumulation of the selected polyphenols in the Fortuna cultivar. The highest ellagic, p-coumaric and syringic acids and relatively higher ascorbic, gallic and caffeic acids were obtained in the plants grown in the Ir50 plot and covered by the S mulch. Consequently, this study shows that the use of the SIr100 application can play a definite role in increasing the productivity of growing strawberries in a high tunnel in the Mediterranean environment.