MSc

With the increasing demand for wood and wood products, tree plantation
activities are expanding at faster rate across the world. The present scenario
demand planting of tree species that offer better economic returns while
contributing to the ecological resilience of the agroecosystems. In this pursuit,
bamboos are excellent group of plants that serve the dual purpose effectively.
Bamboos are the arborescent grasses belonging to family Poaceae. India is the
second richest country of bamboo genetic resources after China. Kerala is one
among the major diversity centers of bamboo in the country and 22 species of
bamboos under seven genera have been recorded from this region. In Kerala
bamboo grows in forests and agroecosystems.
The edaphic and climatic conditions of Kerala permit the cultivation of
diverse species of bamboos. Though bamboos exhibit fast growth, it varies
considerably with species and local conditions. However, information on the
productivity of bamboo especially in the humid tropical conditions of Kerala
are limited. In this backdrop a field study has been designed to evaluate the
comparative growth performance of six bamboo species of high economic and
ecological importance to Kerala viz. Bambusa balcooa, Bambusa tulda,
Bambusa vulgaris, Dendrocalamus asper, Dendrocalamus brandisii,
Dendrocalamus longispathus. The study also probed into the suitable
vegetative propagation techniques for selected three bamboo species
Dendrocalamus longispathus, Dendrocalamus brandisii, Bambusa balcooa.
The field trial was carried out in an existing bambusetum established during
2018 located in Instructional Farm adjoining the College of Forestry campus,
Vellanikkara, Kerala, India. Each of the selected six bamboo species were
grown in randomly allocated blocks. There were 20 clumps per block at a
spacing of 5x5 m. Periodic growth observations were made for clump height,
clump circumference, culm girth, intermodal length, and number of culms.
Propagation trial was carried out in the nursery separately for the three
selected bamboo species viz. Bambusa balcooa, Dendrocalamus brandisii and
Dendrocalamus longipathus treating their culm cuttings with various
concentrations of NAA and IBA. The experiment was laid out in factorial CRD
with three replications. The hormonal combinations were 0, 100, 250 and 500
ppm of both NAA and IBA which were tried separately for the three bamboo
species. The hormone treated culm cuttings were planted in nursery beds and
all routine observations were taken.
There was considerable variation in growth and productivity among the six
bamboo species under study. Bambusa vulgaris and Dendrocalamus brandisii
were the toppers in terms of clump height, clump circumference and culm girth
while Bambusa tulda showed relatively poor growth for these parameters.
Among the species, the highest internodal length was observed for by
Dendrocalamus brandisii and Dendrocalamus longispathus while Bambusa
tulda recorded the shortest internodal length. Number of culms per clump was
highest for Dendrocalamus asper while it was the lowest for Bambusa balcooa.
Overall, among the six species under study, the promising bamboo for humid
Kerala would be Bambusa vulgaris, Dendrocalamus brandisii and
Dendrocalamus asper.
Among the bamboos, the growth hormonal effects were highest for
Dendrocalamus longispathus followed by Bambusa balcooa and the lowest for
Dendrocalamus brandissi. Hormonal treated culm cuttings of Dendrocalamus
longispathus showed significant improvement in plant height, leaf number,
number of roots, root length and rooting percentage while the performance was
poor in the untreated control. In general, IBA showed significantly better
response to plant height, leaf number and rooting percentage for D.
longispathus. Dendrocalamus brandissi showed poor performance for most of
the growth parameters except for root weight. However, apparently better
response were observed for sporting percentage and rooting percentage with
IBA at 250 ppm. The response of untreated control was very poor. Bambusa
balcooa showed significantly better performance for NAA for number of leaves
(250 ppm), number of roots (250 ppm) and root weight (100 ppm). IBA 250
ppm showed better influence on collar girth and root length of B. balcooa non
treated cuttings (control) showed very poor response to all growth parameters.
Overall, the propagation study reveals that growth hormonal treatment of culm
cuttings of Dendrocalamus longispathus and Bambusa balcooa give promising
results for their mass multiplication in nursery conditions.