Effects of a UV-absorbing greenhouse covering film on tomato yield and quality

Abstract

The effect of blocking the ultraviolet (UV) solar radiation using a UV-absorbing low density polyethylene (PE) film on tomato crop yield and fruit quality was evaluated in a two-year study in two arched roof greenhouses located in Central Greece. The UV-A and UV-B radiation transmission values of the greenhouse covered by the UVabsorbing PE film during the first year were 0.4% and 1.2%, respectively and increased to 0.8% and 1.3% in the 2 nd year, while the respective values in the greenhouse covered by a traditional PE film were 20.7% and 12.5% during the 1 st year and 28.7% and 26.7% during the 2 nd year. Under the UV-absorbing film the number of insect injured fruit was reduced and the marketable yield was similar or higher than that under the common PE film, while fruit quality characteristics (size, shape), nutritional value (ascorbic acid and lycopene) and organoleptic quality (pH, titratable acidity and total soluble solids) were similar under both covering materials. Moreover, the reduction of incoming UV radiation had an appreciable effect on fruit skin color, indicating an effect on pigments other than lycopene.Additional key words: fruit quality; insects; polyethylene; transmission; ultraviolet radiation; UV-stabilizers. ResumenEfectos sobre el rendimiento y la calidad del tomate de un film de cubierta de invernaderos absorbente de UV Se evaluó, en un estudio de dos años, en dos invernaderos a dos aguas ubicados en Grecia Central, el efecto del bloqueo de la radiación ultravioleta (UV) solar, utilizando un film absorbente de polietileno (PE) de baja densidad absorbente de UV, sobre el rendimiento del cultivo del tomate y la calidad del fruto. Los valores de transmisión de la radiación UV-A y UV-B del invernadero cubierto por el film PE absorbente de UV en el primer año fueron 0,4% y 1,2%, respectivamente, y se incrementaron hasta el 0,8% y el 1,3% en el segundo año. Estos valores en el invernadero cubierto por una película tradicional de PE fueron 20,7% y 12,5%, respectivamente, durante el 1 er año y 28,7% y 26,7% durante el segundo año. Bajo la película absorbente de UV se redujo el nú-mero de frutos con heridas producidas por insectos y el rendimiento comercializable fue similar o mayor que bajo la película de PE tradicional, mientras que las características de calidad del fruto (tamaño, forma), el valor nutricional (ácido ascórbico y licopeno) y la calidad organoléptica (pH, acidez titulable y sólidos solubles totales) fueron similares con ambos materiales de revestimiento. Por otra parte, la reducción de la radiación UV entrante tuvo un efecto apreciable en el color de la piel de fruta, lo que indica un efecto sobre otros pigmentos distintos del licopeno.Palabras clave adicionales: calidad de la

The effect of covering material on the yield, quality and chemical composition of greenhouse‐grown tomato fruit

“…reported a monthly variation in sugar levels of tomato fruit grown in greenhouses with different cooling systems and further concluded that sugar content was not affected by greenhouse type and climate conditions. In addition, Papaioannou et al . did not find a significant effect of PE cover materials on TSS content of tomato fruit.…”

“…Similarly, Farneti et al 36 reported a monthly variation in sugar levels of tomato fruit grown in greenhouses with different cooling systems and further concluded that sugar content was not affected by greenhouse type and climate conditions. In addition, Papaioannou et al 17 did not find a significant effect of PE cover materials on TSS content of tomato fruit. In addition, Toor et al 37 detected a great variation in TSS content during the growing season for three greenhouse-grown tomato genotypes suggesting a genotype-dependent effect.…”

“…During the last few decades, greenhouse technology for horticultural crops has focused on optimizing environmental conditions within the greenhouse having also in mind to combine maximum yields with minimum production costs. Several studies have reported the effect of covering materials on yield and basic quality parameters of tomato and other fruit vegetables, giving emphasis on sugar and carotenoid contents, titratable acidity, aroma profile and visual appearance . The aim of the study reported here was to evaluate the effect of covering materials and harvesting dates on chemical composition and antioxidant properties of tomato fruit, while at the same time measurements regarding total energy consumption and yield were also carried out.…”

Hydroxycinnamic acids and UV-B depletion: Profiling and biosynthetic gene expression in flesh and peel of wild-type and hp-1

“…A different response to UV-B depletion between the two genotypes was actually not unexpected. Previous studies indicated that the influence of low UV-B radiation levels on ascorbic acid and lycopene levels (Giuntini et al, 2005) and content of total soluble solids in fruits (Krizek et al, 2006) depends on tomato genotype and that the results obtained may be valid only for the tomato cultivar studied (Papaioannou et al, 2012). A genotype-dependence was observed also in two tomato hybrids characterised by a high (DRW 5981) or a low lycopene (Esperanza) content, with DRW 5981 undergoing a decrease and Esperanza an increase in HCAs content in peel following UV-B shielding (Giuntini et al, 2008).…”

Postveraison Deficit Irrigation Effects on Fruit Quality and Yield of “Flame Seedless” Table Grape Cultivated under Greenhouse and Net

“…Anthocyanins synthesis can be affected by many different factors, among them, temperature, light intensity, nutrition, and irrigation [5]. Some of these factors are strongly modified by the use of covering materials in protected cultivation (either under greenhouse or net), thus aggravating poor color development in the skin of the fruit [6]. Cultural practices common in table grape, such as leaf removal and shoot and cluster thinning, seek enhancing berry appearance [7,8], but commonly are not enough to resolve color deficits.…”