Assessment effect of macronutrients on growth and phytochemical contents of Iranian native spinach

Overmuch usage of chemicals in crops, especially in leafy vegetables, caused people exposed to health and environmental risks. In Iran, spinach used as a winter vegetable that believed has high Iron and is useful for anemia. The objective of the experiment was determining optimum usage of each macronutrients for obtaining safe with maximum growth and yield in order to extension among farmers. Treatments were chemical fertilizers including ammonium sulfate, super phosphate triple and potassium sulfate at 50, 100, 150 and 200 kg/h against control in a randomized complete block design. Results showed that nitrogen caused elevation of fresh and dry weight in spinach as the maximum obtained in 200 kg/h ammonium sulfate. Results obtained from effect of phosphorus showed that super phosphate increased fresh and dry weight of spinach; but potassium sulfate had no effect on its growth and yield. Analysis of variance on cross effect of data showed significant differences in fresh and dry weight, number of leaves, chlorophyll content and nitrate, but no in length and wide of leaves.