Supplementary Potassium Sustains Fruit Yield in Bell Pepper under High Ammonium Nutrition

Summary

The uptake of nitrogen (N) in nitrate or ammonium (NH 4 +) form affects physiological and metabolic processes and toxicity may develop in plants receiving high concentrations of NH 4 +. The objective of the present study was to delineate the response of bell pepper plants to varying proportions of NH 4 + combined with increasing concentrations of potassium (K) in the nutrient solution. Bell pepper plants were tolerant to moderate proportions of NH 4 + (25% or less or 50% or less); however, higher proportions resulted in growth reduction. The application of higher K concentrations in the nutrient solution did not ameliorate the growth on vegetative plant parts; however, when K was increased to 9 m m, the yield was sustained even when 50% of total N was in the NH 4 + form. Decreased shoot:ro