Application of potassium has been found to minimize the toxic effect of NH4+ under salt stress. To study the interactive effect of K+ and NH4+ under saline condition, maize (Zea mays L., cv. Pioneer-3335) was grown in a hydroponic culture with ammonium (5.0 and 10 mM) as (NH4)2SO4 at two different levels (3.0 and 9.0 mM) of K+ under control and 100 mM NaCl. Under saline condition, 5 mM NH4+ application along with 3.0 mM K+ decreased the dry mass by 24% in maize while its addition at the rate of 10 mM showed a percent decline upto 70% than the control. A decrease in shoot dry mass induced by the combine application of 5.0 mM NH4+ and 9.0 mM K+ was 19% relative to control whilst a decrease i.e. 52% was observed at 10 mM NH4+ level. The increasing concentration of potassium was found to alleviate the NH4+ toxicity and salinity stress partly by inhibiting the uptake of NH4+ and Na+ and by stimulating the N assimilation in plant body. Growth improvement at combination of 5.0 mM NH4+ and 9.0 mM K+ was reinforced by higher K+ influx into root cells and its translocation to the growing tissues. Elevating the K+ supply also resulted in the enhanced plant growth several times and reduction in NH4+ toxicity and salinity stress.
Munazza Yousra, Javaid Akhtar, Zulfiqar A. Saqib, M. Saqib, M. A. Haq. (2013) Effect Of Potassium Application On Ammonium Nutrition In Maize (Zea Mays L.) Under Salt Stress, , Volume-50, Issue-1.
