EFFECT OF SUBSTRATUM AND NUTRIENT SOLUTION UPON YIELDING AND CHEMICAL COMPOSITION OF LEAVES AND FRUITS OF GLASSHOUSE TOMATO GROWN IN PROLONGED CYCLE

Abstract

In the soilless cultivation of tomato under covers the main factors determining the quantity and quality of obtained yield are the kind of substratum used, as well as the content of nutritional solution dosed under plants. Studies conducted in the glasshouse in the years 2005–2007 were aimed at determining the effect of the substratum of rockwool, perlite and expanded clay, as well as two kinds of nutritreint solution of differentiated macroelement concentrations (EC I – 2.4 mS·cm-1 and EC II – 3.6 mS·cm-1) upon yielding and chemical composition of leaves and fruits of tomato cv. 'Cunero F1', grown in extended cycle (22 clusters). Cultivation was conducted with the use of dripping fertigation system, with closed nutrient solution circuit, without recirculation. In the conducted studies no significant differences were found in the total and marketable yield of tomato grown in the examined substrata. Kind of substratum did not also have any significant effectupon the mean weight of one fruit and number of fruits from a plant. In objects cultivated with a solution with higher macroelement concentration (EC II) significantly higher marketable yield was reported, as well as higher fruit unit weight and less non-marketable fruits compared to the basic nutrient solution (EC I). In the leaves of plants fertilized with solution containing 25% more macroelements (EC II) significantly more total nitrogen, potassium, calcium and magnesium was reported. The fruits of plants fertilized with solution of higher macronutrients concentration (EC II) contained significantly more dry matter (5.71%), nitrogen (2.41% d.m.), phosphorus (0.32% d.m.), potassium (4.23% d.m.), calcium (1096 mg·kg-1 d.w.) and less vitamin C (17.2 mg·100-1g fr.w.) compared to fruit from plants fertilized with basic nutrient solution of EC 2.4 mS·cm-1. In the studies no significant effect of substratum type was found upon the contents of vitamin C, sugars, total nitrogen, phosphorus, calcium and magnesium in tomato fruit