Effect of Phosphate and Nitrogen Nutrition and Seasonal Variation on Growth of Tomato¹

The effect of three sources of phosphate (Single superphosphate, monoammo-nium phosphate and potassium metaphosphate) at three different phosphate levels (30, 60 and 90 kg P₂O₅/ha) in combination with three nitrogen levels (50, 100 and 150 kg N/ha) on the growth of tomato var. Pusa Ruby was studied under field conditions during autumn season of 1963–64 and summer seasons of 1964 and 1965 on sandy loam soil at the Indian Agricultural Research Institute, New Delhi. The three forms of phosphate had similar effects on the final height of the shoot, number of lateral branches and number of leaves per branch. Increasing levels of phosphate increased the number of branches per plant. Final height of the shoot and number of leaves per branch were similar with different levels of phosphate (30, 60 and 90 kg P₂O₅/ha). Nitrogen application increased the plant height, number of branches and number of leaves per branch. Autumn season favoured better growth in relation to summer season.