Interaction of seasons and rooting hormone on sprouting and root length of bamboo seedlings (Bambusa balcooa Roxb. and Dendrocalamus stocksii Munro)

This study investigates the effects of Indole-3-butyric acid (IBA) treatments at various concentrations (500, 1000, 1500, 2000, and 2500 ppm) on sprouting percentage and root length in different seasons (rainy, winter, and summer). An experiment was laid out in completely randomized design with factorial concept (FRBD) having 12 treatment combinations, comprising with two factors. Significant interactions were observed between the seasons and the IBA treatments (A x B). During the rainy season (S1), the highest sprouting percentage was achieved with a 2500 ppm IBA treatment (87.67% in A and 88.67% in B), with a root length of 9.23 cm (A) and 8.77 cm (B). During the winter season (S2), the sprouting percentage reached a maximum of 35.00% (A) and 36.33% (B) with the 2500 ppm IBA treatment, along with a root length of 5.53 cm (A) and 4.44 cm (B). In the summer season (S3), the 2500 ppm IBA treatment yielded the highest sprouting percentage of 86.33% (A) and 94.33% (B), with corresponding root lengths of 11.37 cm (A) and 14.53 cm (B).The study reveals that higher concentrations of IBA generally promoted sprouting and root growth, with significant variations across different seasons. The interactions between the treatments and seasons were significant across all seasons and for both bamboo species. Propagation of bamboo through culm cuttings during the summer season, particularly when treated with Indole-3-butyric acid (IBA), has been shown to be highly effective in summer season (March to May).