Effects of polyethylene and biodegradable starch-based mulching films on eggplant production in a Mediterranean area

Traditional plastic films are used for eggplant cultivation in open field in Mediterranean environments. However, disposal and/or recycle of mulches contaminated with soil and/or vegetation represent an environmental concern. We compared two traditional plastic mulches (transparent and black polyethylene films) with five black biodegradable mulching films (Mater-Bi T12A, Mater-Bi T12B, Mater-Bi T15A, Mater-Bi T15B and Mater-Bi T15C) having different thickness and synthetic composition. 'Birgah' eggplant F1 hybrid plug-plants were transplanted on 2nd May, 2016 in the north-western coast of Sicily. Air temperature in the soil-mulch film gap in the plots with transparent PE was higher than in the plots with the black PE film, biodegradable mulches and control. However, air temperature in the plots with Mater-Bi T12A and Mater-Bi T15B were 0.5-9.7 °C higher than those of the bare soil between 11.00 and 18.00 HR. Percent soil exposure (PSE) for transparent and black PE films were 6.7 and 7.7%, respectively by the end of the cultivation period. While, PSE for Mater-Bi T12A and Mater-Bi T15B was lower than other biodegradable mulching treatments and achieved 63.3 and 63.3%, respectively. Transparent PE film significantly increased plant height at 50 DAT by 14.9%, marketable yield per plant by 6.1%, average fruit weight by 11.1% compared with black PE film, Mater-Bi T12A and Mater-Bi T15B. No significant differences were found among transparent PE, black PE, Mater-Bi T12A and Mater-Bi T15B treatments for TSS and CA content. Mater-Bi T12A and Mater-Bi T15B mulches should be taken in consideration for eggplant production in Mediterranean environments.