Ali Ahmad Yousef (1) , Ghiath Alloush *(2), and Ahmad Jaloul (1)
(1) Horticulture Department, Faculty of Agriculture, Tishreen University, Lattakia, Syria
(2) Soil and Water Science Department, Faculty of Agriculture, Tishreen University, Lattakia, Syria.
(*Corresponding author: Ghiath. Alloush, E-Mail: galloush@scs-net.org ).
Received: 24/03/2021 Accepted:10/06/2021
Abstract:
This study investigates the role of calcium and ammonium ions in the tolerance of tomato (variety Shanon) to salinity induced by NaCl salt in a Hydroponics experiment. The study included four treatments, all with a salt concentration of NaCl (75 mM). Two treatments grown with nitrate and two treatments were grown with ammonium nitrate (50:50), with or without a supplemental concentration of calcium of 25 mM. Growth and nutrient uptakes (N, P, K, Ca, Mg, Na, and Cl) were followed over 6 harvests between 0 and 32 days, both in shoots and roots. The experiment then continued up to fruiting. Fruits were counted, sized, and analyzed for vitamin C, acidity, and soluble solid substances. The positive effect of calcium supplement increased vegetative growth in the case of nitrate feeding only. In the case of a mixed feeding with NO3/NH4, it, despite the improvement in growth, was less significant. The supplemental calcium improved nitrogen, phosphorous, calcium and potassium uptake in the treatment of both forms of nitrogen supply while reducing magnesium and chlorine uptake. NH4NO3 increased the uptake of all nutrients compared to nitrates alone in the absence of additional calcium. Calcium increased the number of fruits, weight, diameter, and size in the case of nitrate feeding alone. In the case of the NH4NO3 nutrition, the increase was not significant in weight and the number of fruits. The supplemental calcium, except for the number of fruits per bunch, had no significant effect on any of these parameters in the treatment of NH4NO3. The supplemental calcium in the case of nitrate feeding only led to a significant increase in vitamin C and in the percentage of acidity. There were no significant effects of NH4NO3 feeding in any of the specific fruit characteristics compared to nitrate nutrition alone.
Keywords: Tomato, hydroponic culture, NaCl, Salinity, N form (NO3/NH4)
Full paper in Arabic: pdf