Influence of electric conductivity management on greenhouse tomato yield and fruit quality

Abstract

-The osmotic and ionic effects of the electrical conductivity (EC) of the nutrient solution and its interactions with climatic factors and cultural practices on tomato yield and fruit quality are reviewed. Adjusting the salinity of the nutrient solution allows growers to modify water availability to the crop and hence improve fruit quality. At some point, however, increases in salinity limit marketable yield. Under high ECs, fruit size is inversely related to EC while the dry matter content of the fruit is linearly increased by the EC. The exact rate of yield decline varies with interactions between cultivars, environmental factors, composition of the nutrient solution, and crop management. According to different studies and growth conditions, salinities higher than 2.3-5.1 mS⋅cm -1 result in an undesirable yield reduction, while ECs of 3.5-9.0 mS⋅cm -1 improve tomato fruit quality. Manipulating the indoor climate such as humidity, temperature and ambient CO 2 level may offset the negative effect of high salinity on yield and fruit quality such as blossom-end rot. The light intensity received by the plant directly affects the quantity of photoassimilates available to the fruit, it also increases their sugar: acid ratio, and influences the transpiration rate and the water uptake by the plant, which in turn, affect the EC around the root. Increasing the EC with NaCl reduces titratable acids, potassium and nitrogen in the fruit but also increases their sodium content. NaCl enhances the sweetness of tomato fruit and improves the overall flavour intensity. Depending upon the composition of the saline solution, ion toxicities or nutritional deficiencies may arise because of a predominance of specific ion or competition effects among cations and anions. Keeping the proper nutrient levels and ratios between all the nutrients in the root environment for each growth stage of a crop should be targeted in order to achieve high yields and high quality products throughout the cropping season. Several EC and fertigation management regimes could improve fruit quality and are presented in this review.Lycopersicon esculentum / tomato / electrical conductivity / salinity / fruit quality / greenhouse Résumé -Influence de la régie de la conductivité électrique de la solution nutritive sur le rendement et la qualité de la tomate de serre. Cette revue de littérature porte sur les effets osmotiques et ioniques de la conductivité électrique (CE) de la solution nutritive et de ses liens avec les facteurs climatiques et culturaux sur le rendement et la qualité de la tomate de serre. L'ajustement de la salinité de la solution nutritive permet aux producteurs de modifier la disponibilité en eau pour la plante de façon à contrôler la qualité des fruits. Cependant, des salinités élevées affectent le rendement vendable. Sous une haute CE, le calibre des fruits est inversement relié à la CE alors que le contenu en matière sèche des fruits augmente linéairement avec la CE. Le taux de réduction du rendement varie selon les interactions e...

Reuse of substrate and nutritive solution concentration on the cultivation of salad tomato

“…Consequently, there is a decreasing trend on cellular volume, fruit size and tomato yield. Dorais et al (2001) reported the effect of salinity in tomato cropping and verified that losses in productivity arise mainly from losses of average fruit weight.…”

“…Probably, the increase of the nutritive solution's concentration benefits the fixation of fruits only until the 142% concentration, which from that, reductions were noted. According to Dorais et al (2001), the number of flowers per raceme can be influenced negatively due to high salinity, influencing the fixation, fruit quality and yield.…”

Influence of organic and mineral fertilizers on chemical and biochemical compounds content in tomato (Solanum lycopersicum) var. Mongal F1

“…Further, Tohill et al (2004) suggested that fruits and vegetable intake have positive effect on weight management and obesity prevention. The biochemical composition of tomato fruit varies according to the variety, environmental factors such as light, temperature, fertilization and farming practices (Dorai et al, 2001). Yanar et al (2011) evaluated the effects of different organic fertilizers on yield and fruit qualities of indeterminate tomato and reported satisfactory increases in the tomato yield and quality in plant treated by organic fertilizers.…”

The Use of Artificial Wetlands to Treat Greenhouse Effluents

“…This excess part of the nutrient solution is then recycled or lost in the environment if no strict regulation is in place. Growers may be reluctant to recycle their effluents due to the risk associated to pathogens, the cost and maintenance of a disinfection system (UV, heat, ozone) or the difficulty to maintain an optimal nutrient balance (buildup of SO 4 , Na, Cl) under specific growing conditions (Dorais et al, 2001;Dorais and Dubé, 2011). Unfortunately, these effluents are rich in nitrate and phosphate, which can have a major impact on the environment (Merlin et al, 2002;Dorais and Dubé, 2011).…”