Fruit Yield of Tomato Cultivated on Media with Bicarbonate and Nitrate/Ammonium as the Nitrogen Source |
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| Authors: | Jan Bialczyk Zbigniew Lechowski Dariusz Dziga Ewa Mej |
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| Institution: | 1. Department of Plant Physiology and Development , Jagiellonian University , Kraków, Poland;2. Department of Plant Physiology and Development , Jagiellonian University , Kraków, Poland;3. Department of Plant Physiology , Swietokrzyska Academy , Kielce, Poland |
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| Abstract: | ABSTRACT This article presents the effects of nitrate/ammonium (NO3 ?/NH4 +), applied at different proportions to the root media with or without 5 mmol bicarbonate (HCO3 ?), on the yield and chemical composition of tomato fruit. Tomato plants were grown hydroponically (pH 6.9) in glasshouse conditions. The yield of fruit fresh matter from four clusters obtained from plants grown on the medium with NH4 + was about 25% lower than from the plants grown on the medium containing NO3 ? as the nitrogen (N) source. Supplying NO3 ?/NH4 + at a ratio of 4:1 increased the fruit yield by about 20% in comparison with the value recorded for NO3 ??plants. The enrichment of the medium with HCO3 ? stimulated the bearing, while the result depended on the ratio of NO3 ?/NH4 +. A combined treatment of HCO3 ? with NO3 ? or NH4 + in the medium increased yields by about 28% and 11%, respectively, in comparison to plants cultivated without HCO3 ?. The application of NO3 ?/NH4 + at ratios of 4:1 and 1:1 with HCO3 ? increased the respective yields by about 16% and 10% in comparison with plants grown without HCO3 ?. Modifications in the composition of the media affected the accumulation of organic solutions in the fruit. The NH4 + nutrition effected a 20% decrease in the accumulation of reducing sugars in the fruit in comparison to the fruit of plants grown in media with NO3 ?. In the cultivation of plants in media with various NO3 ?/NH4 + proportions the intermediate values of the reduced sugar concentrations were recorded in comparison with the values obtained for NO3 ??plants and NH4 +?plants. The enrichment of media with HCO3 ? increased the concentration of sugars in fruit from about 28% (for NO3 ??plants) to about 10% (for NH4 +?plants). Malate and citrate are the main constituents of carboxylates in tomato fruit. The form of nitrogen applied to the medium did not significantly affect the concentration of carboxylates in fruit. Significant differences in carboxylate concentrations appeared in fruit grown on media enriched with HCO3 ? ions. In comparison with the cultivation without HCO3 ?, increases in the accumulation of carboxylates varied from about 22% to 30% depending on the form of the applied nitrogen. The concentration of amino acids in the fruit of plants grown with NH4 + exceeded that in NO3 ??plants by about 55%. In the plants grown on media of modified NO3 ?/NH4 + proportions, the concentration of amino acids in fruits were positively correlated with the level of NH4 + in the medium. The enrichment of media with HCO3 ? stimulated a further increase in amino acid concentration in fruit by about 9% in NO3 ? plants and about 21% in NH4 + plants compared with the respective control (without HCO3 ?). |
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| Keywords: | ammonium bicarbonate fruit yield nitrate tomato |
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