Effect of nitrogen and phosphorus levels on yield of China aster and changes in fertility status

An experiment was carried out at the Satpuda Botanical Garden, College of Agriculture, Nagpur, during 2024 -25 to study the effect of different nitrogen (N) and phosphorus (P) levels on the growth and seed yield of China aster. As many nine treatment combinations, consisting of three nitrogen levels (150, 187.5, and 225 kg ha⁻¹) and three phosphorus levels (50, 62.5, and 75 kg ha⁻¹), each replicated three times were tested in a factorial randomized block design. Results revealed that, application of 225 kg N ha⁻¹ recorded maximum number of flowers per plant, seed yield per hectare. The pH of soil (7.92), EC of soil (0.35 dS m⁻¹), organic carbon (5.80 g kg⁻¹), CaCO₃ (4.23 percent), available N in soil (289.42 kg ha⁻¹), available P in soil (23. 58 kg ha⁻¹), available K in soil (301.78 kg ha⁻¹) and available S in soil (8.17 mg kg⁻¹) were observed significantly higher with application of 225 kg N ha⁻¹. Similarly, phosphorus levels also influenced growth and yield significantly. The maximum number of flowers per plant (28.54), seed yield (119.42 kg ha^-1) and pH of soil (7.90), EC of soil (0.33 dS m^-1), organic carbon (5.49 g kg⁻¹), CaCO₃ (4.21 percent), available N in soil (292.58 kg ha⁻¹), available P in soil (22.12 kg ha⁻¹), available K in soil (303.01 kg ha⁻¹) and available S (7.75 mg kg⁻¹) were recorded. The interaction effect showed that the combination of 225 kg N ha⁻¹ with 62.5 kg P ha⁻¹ proved to be most effective in achieving maximum seed yield along with optimum soil fertility.