Articles
EFFECT OF DIFFERENT EC MANAGEMENT ON YIELD, QUALITY AND NUTRACEUTICAL PROPERTIES OF TOMATO GROWN UNDER SUPPLEMENTAL LIGHTING
Article number
580_32
Pages
241 – 247
Language
English
Abstract
The yield, quality and nutraceutical properties of greenhouse tomato grown under supplemental lighting and using three different electrical conductivity (EC) management strategies were determined.
The three EC management treatments were: 1) control EC; 1.8 to 3.5 mS cm-1 according to the solar radiation, 2) NaCl EC; EC equal to the control where macronutrients were used to obtain 1.8 mS cm-1 and NaCl was added to raise the EC to the control level, and 3) variable EC; low EC (1.5 to 2.7 mS cm-1) during the active growth period of the day (10-14 h) and high EC (3 to 4 mS cm-1) for the remaining part of the day.
Tomato fruit was harvested 2 to 3 times per week from March to the end of June 2000 and fruit quality was graded into 4 categories according to the incidence of physiological disorders.
The total yield, percentages of grade 1, 2 and 3 fruits were not significantly affected by EC management treatments, but the incidence of blossom-end rot (P=0.0003) and the percentage of grade 4 fruits (P=0.01) were significantly reduced by NaCl and variable EC treatments.
NaCl did not affect the nutraceutical properties of tomato fruit such as antioxidant vitamins (ascorbic acid,
-tocopherol), carotenoids (lycopene, 
-carotene, and lutein), and flavonoids (quercetin). However, variable EC resulted in an increase of -tocopherol and lycopene concentrations and a decrease of ascorbic acid and -carotene concentrations.
The three EC management treatments were: 1) control EC; 1.8 to 3.5 mS cm-1 according to the solar radiation, 2) NaCl EC; EC equal to the control where macronutrients were used to obtain 1.8 mS cm-1 and NaCl was added to raise the EC to the control level, and 3) variable EC; low EC (1.5 to 2.7 mS cm-1) during the active growth period of the day (10-14 h) and high EC (3 to 4 mS cm-1) for the remaining part of the day.
Tomato fruit was harvested 2 to 3 times per week from March to the end of June 2000 and fruit quality was graded into 4 categories according to the incidence of physiological disorders.
The total yield, percentages of grade 1, 2 and 3 fruits were not significantly affected by EC management treatments, but the incidence of blossom-end rot (P=0.0003) and the percentage of grade 4 fruits (P=0.01) were significantly reduced by NaCl and variable EC treatments.
NaCl did not affect the nutraceutical properties of tomato fruit such as antioxidant vitamins (ascorbic acid,
-tocopherol), carotenoids (lycopene, -carotene, and lutein), and flavonoids (quercetin). However, variable EC resulted in an increase of -tocopherol and lycopene concentrations and a decrease of ascorbic acid and -carotene concentrations.
Authors
Z.-Q. Shi, F. Jobin-Lawler, A. Gosselin, G. Turcotte, A.P. Papadopoulos, M. Dorais
Keywords
antioxidant, carotenoid, electrical conductivity, fertigation, flavonoid, Lycopersicon esculentum, russeting, salinity, vitamins
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