The supply of potassium to plants stimulates the efficient use of nitrogen through plant uptake and assimilation, consequently increasing crop yield. The aim was to evaluate the effect of combined rates of nitrogen and potassium on growth and assimilation of nitrogen in wheat plants. The experiment was performed in a greenhouse, Piracicaba, SP Brazil. Three-liter pots were filled with 0-0.2 m depth samples of Arenic Hapludult. A fractionated 5² factorial was used, with combinations of five nitrogen rates (0; 70; 140; 210 and 280 mg dm-3) and five potassium rates (0; 50; 100; 150 and 200 mg dm-3), which were set in a randomized block design, with four replications. The combination of the highest nitrogen and potassium rates increased shoot growth and the chlorophyll content in leaves. The accumulation of nitrogen and potassium in leaves was increased only by rates of these nutrients separately. The potassium did not influence the nitrate reductase activity and the accumulation of nitrogen in plant tissue.
Triticum aestivum L; nitrate reductase activity; SPAD measurements
