Relationship of Season and Cuttings' Diameter with Rooting Ability of Culm-Branch Cuttings in Bambusa tulda and Bambusa nutans

Bamboo propagation through conventional methods like seeds and rhizome has limitations of availability pose practical and economic constraints and are, by and large non-sustainable. To overcome the situation, macro-propagation efforts of commercially important Bambusa tulda Roxb. and Bambusa nutans Wall. have been endeavored. Season and cuttings' thickness is influential in determining rooting ability in culm-branch cuttings of these two species. Age of donor culm, treatment concentration and duration, rooting substratum, temperature, and humidity are other affecting factors. Present study exhibited initiation of sprouts within a week after planting of cuttings, whereas adventitious rooting initiates in 20 days after planting. Culm-branch cuttings planted during spring-summer in March and sampled after 60 days reveals 63.39% and 72.68% rooting ability, respectively in <= 2.0 cm diameter (thin) and > 2.0 cm diameter (thick) cuttings of Bambusa tulda and 73.60% and 69.02% rooting ability, respectively in thin and thick cuttings of Bambusa nutans. Rooting ability of branch cuttings decline in rainy season followed by autumn-winter in two diameter classes of both species. Sprout number, sprout length, number of primary adventitious roots, and root length of the longest root was comparatively higher during spring-summer than rainy and autumn-winter season in thin and thick cuttings of both species. Propagation through culm-branch/sub-branch cuttings is without hampering economic value of culms and therefore, a non-destructive, cheap, and easy to handle technique of large scale production of planting stock. Strong relationship between season and rooting ability will help in achieving planting stock production targets of forest nurseries.

Automated summary

The study demonstrates that different seasons and cutting thicknesses have an impact on the rooting ability of Bambusa tulda and Bambusa nutans culm-branch cuttings. Cuttings planted in spring-summer exhibit better rootability, while those planted in rainy and autumn-winter seasons show lower rooting abilities.