Effects of Organic Acids on Uptake of Essential Nutrients by Tomato Plants and Their Impacts on Growth at an Early Stage

Page(s): 10 (1), 1-13, 23 Ref.The effect of organic acids (oxalic and citric acids) applied at low concentrations (0.0, 0.5 and 1.0 mM) on the uptake of phosphorus and other essential macro- and micro-nutrients by tomato plants (Lycopersicon esculentum Mills.) of the cultivar Pomodora were investigated. The plants were grown on a full Hogland's solution in a greenhouse at King Faisal University for 76 days, from mid-December 1998 to end of February 1999. The effects of nutrients uptake on growth parameters at an early stage were evaluated. The results showed that the addition of these acids significantly decreased the level of P uptake by the plants. Significant variations in the absorption of other nutrients were also obtained. However, the measured growth parameters showed that the plants grew better in solutions treated with these acids than those in the untreated solutions. This suggests that a balanced absorption of the nutrients occurred as a result of the addition of oxalic and citric acids.Khartoum University Pres