Effect of plant spacing and GA₃ on growth and flowering of sweet william (Dianthus barbatus L)

The present study was carried out to work out the optimum plant spacing and GA₃ dose for growth and flowering of sweet william. The experiment was laid out in RBD (factorial) with 12 treatment combinations of four levels of spacing viz S₁(30 × 30 cm), S₂(30 × 25 cm), S₃(30 × 20 cm) and S₄(20 × 20 cm) and three doses of GA₃ viz G₀(0 ppm), G₁(50 ppm)and G₂(100 ppm)replicated thrice. Theresultsobtained indicated maximumvaluesfortimetakentofirst flowering (131.67 days), plant spread (38.78 cm), number of flowers per plant (106.11), size of flowers (1.86 cm) and duration of flowering (39.11 days) at a spacing of 30 × 30 cm (S₁). Whereas maximum plant height (46.07 cm) and number of flowers per plot (2600.00) were noticed at a spacing of 20 × 20 cm (S₄). The application of GA₃ @ 100 ppm resulted in highest values for plant height (42.67 cm), plant spread (36.54 cm), number of flowers per plant (96.75), number of flowers per plot (2349.75), size of flowers (1.83 cm) and duration of flowering (36.75 days). However GA₃ @ 0 ppm recorded maximum values for days taken to first flowering (117.83). The interaction S₁ (30 × 30 cm) × G₂ (100 ppm) recorded maximum values in terms of most of the growth and flowering parameters except number of flowers per plot which were found to be maximum in the interaction S₄ (20 × 20 cm) × G₂ (100 ppm) but the effects were found to be non-significant. It was concluded that for better growth and flowering the plants of sweet William be spaced at 30 × 30 cm apart along with the application of GA₃ @ 100 ppm after 40 and 60 days of transplanting.