Effect of GA₃ and Growing Medium on Growth, Flowering and Com Production in Gladiolus

The experiment was conducted to find out the effect of GA₃ and sand on gladiolus cv. Congo Song. Results showed that most of the vegetative, floral and stock production parameters were influenced significantly by pre-planting soaking of corms in gibberellic acid (50, 100 and 150 ppm) for 24 hours as well as planting them with (S₁) or without (S₀) sand dressing. The higher levels of GA₃ (100 or 150 ppm) in both the media-sand (S₁) or soil (S₀) resulted favourable influences on most of the characters studied. Interaction of GA₃ (150 ppm) with sand dressing (G₃ x S₁) resulted maximum number of sprouts and the earliest spike emergence, thickest plant, longest unopened floret and the highest yield of spikes/ha; while 100 ppm GA₃ with sand (G₂ x S₁) resulted the wider placement of floret, corm and maximum yield of corm/ha. The combination of 150 ppm (GA₃) with no dressing of sand (G₃ x S₀) resulted in maximum number of leaves/plant and number of opened fresh florets at a time. As compared to planting without sand dressing (S₀), application of 100g sand beneath the corm delayed spike emergence, hastened the colour break in terminal floret and increased the number of sprouts/mother corm, number of leaves/plant, girth & height of plant, length of unopened floret, placement of florets, number of opened fresh florets at a time, total yield of spikes & daughter corms/ha and number of cormels/plant.