Yield and Quality Traits of Tomato ‘San Marzano’ Type as Affected by Photo-Selective Low-Density Polyethylene Mulching

Abstract

The aim of the present study is to investigate the effect of differently colored low-density polyethylene mulching films (black, silver/brown, and yellow/brown) in comparison with bare soil (BS) on soil temperatures, yield and yield components (number of fruit and average fruit weight), and fruit quality traits (color, firmness, total soluble solids content, polyphenols, flavonoids, ascorbic acid, carotenoids, and antioxidant activity) of a ‘San Marzano’ tomato crop grown in Southern Italy over two years (2014 and 2015). The warmer season (2015) shortened the cropping cycle (124 vs. 178 days, 2015 vs. 2014), thereby accelerating fruit ripening and improving firmness and redness (on average, the color parameter a/b was greater than in 2014). It determined the best yield response (53 vs. 44 Mg ha−1) by increasing the number of commercial fruits per unit land area despite the lower average fresh weight (AFW) than the first year. Regardless of the different plastic films, in both years, soil heat storage produced by mulching improved yield as compared to BS and showed a positive and significant effect on the contents of total soluble solids, polyphenols, flavonoids, and carotenoids without affecting the antioxidant activity. The highest values of quality traits were reached in the second year with silver and yellow mulches. Therefore, since the colored mulching films (yellow and silver) had a contradictory effect on yield and quality in the two years, further investigation is desirable.