Effect of Foliar Spray with K and Mn on the Growth of Swietenia mahagoni (L.) Jacq. under Different Drought Levels
Kamal ShaltoutMohamed Motawee, Dalia Ahmed, Mohamed EL- Etreby
The present study aims to study the effect of foliar spray of two chemical fertilizers (Potassium sulphate K2SO4 and manganese sulphate MnSO4) on growth and drought tolerance of Swietenia mahagoni (L.) Jacq. seedlings to obtain their highest growth using the lowest available water resources. An experiment was carried out in an open field of Gemmeiza Agricultural Research Station during February to December 2020. Three levels of water stress were applied (100, 75, and 50 % field capacity). Three concentrations of K2SO4 were applied as foliar spray (0, 4 and 6 g L-1), and 3 concentrations of MnSO4 (0, 2 and 4 g L-1). The results indicated that plant height, stem diameter, leaf number, leaf area, fresh and dry weight of the plant organs, relative water content, shoot / root fresh and dry weight ratios and total chlorophyll, were decreased with increasing levels of drought stress. Both K2SO4 and MnSO4 spray significantly mitigated drought stress by increasing vegetative growth parameters (plant height, stem diameter, leaf number, leaf area, root length, fresh and dry weight of roots, stems and leaves, total fresh and dry weight, relative water content, shoot / root fresh and dry weight ratios, water use efficiency) and biochemical parameters (chlorophyll a and b contents, Proline contents, and carbohydrates of leaves) of S. mahagoni seedlings. Concentration 6 g L-1 of K2SO4 spray is highly effective than other treatments.