Influence of nitrogen and potassium application on yield and quality of sweet william (Dianthus barbatus L) seed

The present investigations were carried out at the experimental farm of Department of Seed Science and Technology, Dr Yashwant Singh Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh with the objective to work out optimum doses of nitrogen and potassium for better seed yield and quality of sweet william during 2017–18. The experiment was laid out in RBD (factorial) with 16 treatment combinations of four levels of nitrogen viz N₀ (0 g/m²), N₁(20 g/m²), N₂ (30 g/m²) and N₃(40 g/m²) and four doses of potassium viz K₀ (0 g/m²), K₁ (10 g/m²), K₂ (20 g/m²) and K₃ (30 g/m²) along with a constant dose of FYM @ 5 kg/m² and P @ 20 g/m² replicated thrice. Among different levels of nitrogen application of N₃ (N 40 g/m²) recorded maximum values for number of capsules per plant (98.36), number of seeds per capsule (49.20), seed yield per plot and per hectare (82.06 g and 820.58 kg respectively), 1000-seed weight (0.99 g), germination (92.69%), speed of germination (15.91), seedling length and dry weight (7.60 cm and 5.19 mg respectively), seed vigour index-I (704.83) and seed vigour index-II (481.36). The application of potassium 30 g/m² resulted in highest values for number of capsules per plant (88.64), number of seeds per capsule (45.10), seed yield per plot and per hectare (72.28 g and 722.75 kg respectively), 1000seed weight (0.96 g), germination (91.06%), speed of germination (15.32), seedling length and dry weight (7.37 cm and 5.07 mg respectively), seed vigour index-I (672.43) and seed vigour index-II (464.13). The interaction N₃ (40 g/m²) × K₃ (30 g/m²) recorded significantly maximum values in terms of the seed yield and quality parameters and effects were found to be significant. Therefore it is concluded that for getting maximum seed yield and producing better quality seeds the plants be fertilized with N: K 40: 30 g/m² along with FYM 5 kg/m² and P 20 g/m².