fruit quality and yield of tomato as influenced by rain shelters and deficit irrigation

this study was conducted to determine the effects of the combined use of rain shelters (rs) and deficit irrigation (di) on tomato yield and quality characteristics. two experiments with different treatments were conducted in the southern china during the growing season in 2011 and 2012. the crops were irrigated to field capacity once average soil water content at the 0-60 cm layer in the treatment decreased to 80% of field capacity under open-field (t1, the control) and rs (t2), and 30, 40, and 50% decreased water of t2 as treatments t3, t4, and t5, respectively. the results showed that t2 increased the yield and irrigation water use efficiency (iwue) by 13 and 11.5% in the two years, and improved fruit firmness (ff), total soluble solids (tss), soluble sugar (ss), and vitamin c (vc) compared to t1. under rs conditions, di reduced the yield, but increased iwue of tomato relative to t2 from 25 to 52% in 2011, and from 26 to 41% in 2012. the effects of di on fruit quality were generally the inverse of those on fruit yield. ff, tss, ss, vc, organic acid, and color index were positively affected by di. with regard to the rank of comprehensive quality index (cqi) calculated by the analysis hierarchy process and modified technique for order preference by similarity to an ideal solution, it exhibited good fitness to the rank of single quality attributes. the highest cqi was obtained in treatment t4 in 2011, and t3 in 2012.