Plant growth regulator based corm priming in improving vegetative growth, flowering and corm yield of freesia (Freesia × hybrida)

Freesia (Freesia × hybrida) is an important ornamental bulbous crop valued for its elegant flowers and commercial potential as a cut flower and potted plant. However, delayed and non-uniform sprouting of corms often leads to poor establishment and reduced productivity. To overcome these constraints, the present study was undertaken to evaluate the role of plant growth regulator (PGR)-based corm priming in improving growth, flowering, and corm yield of Freesia × hybrida. The experiment was conducted during 2024-25 at Punjab Agricultural University, Ludhiana, using nine treatments comprising gibberellic acid (GA₃) at 100 and 150 ppm, potassium nitrate (KNO₃) at 3% and 4%, and their combinations, including a control, in a Randomized Block Design with three replications. Results revealed that the combination GA₃ 150 ppm + KNO₃ 3% (T₈) was the most effective in reducing days to sprouting to 9.33 (25.7% earlier) and increasing sprouting percentage to 91.22%. Plant height and spread at 90 DAS were 25.22 cm and 18.67 cm, showing 32.6% and 48.7% increases over control. T₈ also exhibited early flowering (105.56 days), larger flowers (4.31 cm), longer flowering duration (16.87 days), and highest corm yield (13.67 g) with a 33.6% increase over control. Hence, pre-planting corm priming with GA₃ 150 ppm + KNO₃ 4% can be recommended for enhancing growth, flowering, and productivity of Freesia × hybrida under subtropical conditions.