ISHS Acta Horticulturae 718: III International Symposium on Models for Plant Growth, Environmental Control and Farm Management in Protected Cultivation (HortiModel 2006)
APPLICATION OF MIXTURE THEORY FOR OPTIMIZING THE MINERAL NUTRITION IN SOILLESS-GROWN TOMATO |
| Authors: | S. Fanasca, Y. Rouphael, C.M. Rivera, G. Colla |
| Keywords: | Lycopersicon esculentum L., Mixture theory, mineral nutrition, quality |
| Abstract:
This study describes an application of Mixture theory for optimizing cation proportions (K+, Ca²+, Mg²+, Na+) of hydroponically-grown tomatoes. A simplex lattice design {4,2} was used to compare 10 treatments with different proportions of K+:Ca²+:Mg²+:Na+. The cation treatments were differentiated in “vertex” and “mid points” treatments with high proportion of one or two cations in nutrient solution, respectively. The highest total and marketable yield were observed in treatment with high proportion of K+ (avg. 3.21 and 3.08 kg plant-1, respectively) and K+Ca²+ treatment (avg. 3.37 and 3.29 kg plant-1, respectively), while treatments with high proportion of Mg²+ (avg. 2.67 and 2.40 kg plant-1, respectively) and Na+ (avg. 2.13 and 2.03 kg plant-1, respectively) gave the lowest values. Fruit quality [total soluble solids (TSS), titratable acidity (TA), EC and TSS/TA] improved by increasing the proportion of K+ and Na+, good performances were also registered in “mid points” treatments Ca²+Mg²+ and Ca2+Na+ for TSS and TSS/TA. According to the Mixture theory, model was fitted to the marketable yield and TSS data with good results (R² = 0.99** for both models). | |
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