Pseudoxytenanthera stocksii (Munro) T.Q. Nguyen is naturally distributed in Central Western Ghats and is considered an extremely manageable thorn less bamboo species with economic potential suited for domestication in farmlands. A study was taken up in 2013-14 to assess the distribution and natural variation of this species in its natural distribution range. Dendrocalamus stocksii accessions were collected from over 100 locations between Ratnagiri, Maharashtra to Kasargod, and Kerala from elevation ranging between 0.6 m to 909.1 m.asl. Only 5 accessions were from mixed forest types and 3 from waste lands/degraded landscapes while the rest of the 92 D. stocksii accessions were collected from private lands of farmers. There was significant variation in most of the culm parameters between the accessions. Coefficient of variation of all the culm parameter was < 30% except for commercial culm height and culm wall thickness to diameter ratio (cw: cd). Culm diameter at fifth internode varied from 6.25 mm to 57.32 mm with a mean of 37.39 mm while culm height varied between 16.2 m and 5.4 m with an average of 10.0 m and height of culm solidness from the culm base ranged between 2.90 m to 13.00 m across the 100 accessions.The morphological variation between various accessions of P. stocksii in Central Western Ghats and among the populations indicate that there is tremendous scope for selection and improvement within the species.
Pseudoxytenanthera stocksii (Munro) T.Q. Nguyen is a valid accepted name as per the world checklist of selected plant families. Oxytenanthera stocksii Munro, Dendrocalamus stocksii (Munro) M. Kumar, Remesh and Unnikrishnan and Pseudoxytenanthera stocksii (Munro) H.B. Naithani are considered as synonyms of Pseudoxytenanthera stocksii (Munro) T.Q. Nguyen. Pseudoxytenanthera stocksii is naturally distributed across the Western Ghats.
Known locally by different names like Chivari or Mes in Maharashtra and as Marihal, Konda, Oor and Shema in Karnataka, P. stocksii is found primarily in the Central Western Ghats from Kasargod in Kerala to Ratnagiri in Maharashtra. Thereby it its distribution encompasses the states of Karnataka, Goa, Kerala and Maharashtra. P. stocksii is a medium sized bamboo species, having stout solid and strong culm. Culm attains a height of 9 m and diameter of 2.5-5.8 cm with internode length of 15-29 cm. Its leaves are 10-20 cm long with 1-2 cm broad, linear, petiole (2 mm) with a culm sheath 15-22 cm long and 1-17 cm broad, straight, silvery with a glossy appearance.
The species is also cultivated in the coastal belt of Karnataka (Seethalakshmi and Mukteshkumar, 1998). Dewar (2000) has primarily reported that the species isplanted around the arecanut gardens and paddy fields. The species is considered as an important agroforestry species, ideal for plantations in on stream embankments and farm boundaries in coastal regions. The species are loosely placed thus providing flexibility in harvesting, easy management and steady income to farmers.
Commercial plantations (block and mixed) of this species are also seen in the Konkan belt and currently each 15-20 feet culm is sold for Rs 50/- to 200/-. It is also a valuable multipurpose bamboo used as a substitute for cane/ rattan in bamboo based furniture industry. Besides its uses in agriculture, it has immense utility potential in handicrafts and farm implements. Recent studies have also explored the edible shoot properties of the bamboo (Sowmya and Viswanath, 2015; Viswanath and Sowmya, 2016). Overall, P. stocksii is considered as an extremely manageable bamboo species with great economic and ecological importance (Singhal and Gangopadhyay, 1999) finding large scale utilization in scaffolding, paper and pulp, crafts, construction, basket making, umbrella handles and poles. Culms of this species are thornless in nature, with non-prominent nodes and better cw/cd (culm wall thickness to culm diameter) and hence regarded as the best bamboo species in the < 5 cm diameter category for construction and furniture industry (Viswanath et al., 2013).
It is rare to find significant variation in morphological and physical characteristics in culm and clump characters within a species in its natural distribution range. Variation in culm diameter, height, internode length and leaf area of 12 candidate plus culms (CPC) of Dendrocalamus strictus varied between 2.35-2.86 cm, 333.3-423.3 cm, 13.17-16.00 cm and 51.11-103.71 cm2 respectively in dry deciduous forests of Uttar Pradesh (Singh et al., 2004). High levels of variation for vegetative characters were observed between 17 populations of Bambusa tulda in West Bengal (Battacharya et al., 2006). Niwedita et al. (2001) through a similar expedition identified twelve diversified CPCs from different forest divisions of the Vindhyan region inferring that variability exists for morphological characters among the individuals of D.strictus bamboo species for various culm characteristics.
A study was taken up to check the distribution and natural variation in this species in the entire area of its geographical distribution starting from Kasargod of Kerala up to Ratnagiri of Maharashtra in 100 locations covering a distance of 850 km. Offsets from the identified 100 genotypes were used for establishing a P. stocksii germplasm bank at Central nursery Honnavara, Karnataka Forest Department, DBSKVV, Dapoli Maharashtra and in Gottipura field station, Hosakote of IWST Bengaluru for further observations and improvement studies.
(Written by Ajay D. Rane, Sowmya C, Ashwini S, Sruthi S and S. Viswanath, for more details, please download the Karnataka Forest Department's, 'My forest' Journal (September - December 2015), from aranya.gov.in)
