TITLE:
Accumulation of Mineral Nutrients and Phytochemicals in Lettuce and Tomato Grown in High Tunnel and Open Field
AUTHORS:
Amanda Woolley, Samuel Sumpter, Myungjin Lee, Jingwen Xu, Shannon Barry, Weiqun Wang, C. B. Rajashekar
KEYWORDS:
High Tunnel, Lettuce, Mineral Nutrients, Nutritional Quality, Phytochemicals, Tomato
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.10 No.1,
January
18,
2019
ABSTRACT: High tunnel production of horticultural food crops
is becoming increasingly popular and has a significant impact on their growth,
productivity and nutritional quality. The present study examines the effect of
high tunnel production of lettuce (Lactuca sativa cv. “Two Star” and “New Red
Fire”) and tomato (Solanum lycopersicum cv. “Celebrity” and “Mountain Fresh”) on their nutritional quality relating to major nutrients and health-promoting phytochemicals.
High tunnel environment increased the concentration of N (protein) in both
lettuce and tomato relative to the open field cultivation. The accumulation
pattern of mineral nutrients in high tunnel was similar in green-leaf and
red-leaf lettuce varieties. Lettuce varieties grown in high tunnel had higher
accumulation of C, S and Zn relative to those grown in open field. However,
high tunnel environment suppressed the accumulation of many micronutrients such
as Mg, Fe, Cu and Mn in both lettuce varieties but not in tomato. For example,
accumulation of Fe was reduced by more than 80% in “Two Star” and by more than 55% in “New Red Fire” under high
tunnel. It also suppressed the levels of many health-promoting phenolic
compounds such as chlorogenic acid, chicoric acid, rutin and kaempferol in
green-leaf lettuce and gallic acid in red-leaf lettuce. High tunnel environment
improved the soil nutrient status but reduced the radiation levels (PAR, UV-A
and UV-B) received by the crops. The results show that the high tunnel
production has a significant impact on the nutritional quality relating to
protein and mineral nutrients in both crops and health-promoting phytochemicals
in lettuce.