Evaluation of site quality preferences of kawayan tinik (Bambusa blumeana Schultes) at Dumanjug bamboo production project, Dumanjug, Cebu [Philippines]

The results of stepwise regression analysis show that 78.70 percent of the variation in culm diameter growth could be explained by slope gradient, elevation, exchangeable magnesium, and organic matter content. For culm height growth, only 18.20 percent could not be explained by the predictive equation using exchangeable magnesium, position on slope, slope gradient and total nitrogen in the soil. For clump diameter growth, 78.80 percent of its variation could be explained by using available phosphorus, elevation, cation exchange capacity and soil depth. For the number of culm in a bamboo stand, 17.50 percent of this variation could not be explained by using available phosphorus, cation exchange capacity, soil depth and elevation as estimator. For the number of shoots, 81.70 percent of its variation could be accounted for by available phosphorus, soil depth, exchangeable potassium and cation exchange capacity. Lastly, culm dry weight could be estimated using exchangeable magnesium, position on slope, soil depth and soil moisture which account for 78.40 percent of the variation. It was also observed that productive plots were those with average soil chemical attributes of 13.89 ppm for available phosphorus, 1,135.00 ppm for exchangeable magnesium, 65.77 ml per 100 g for cation exchange capacity, 205.67 ppm for exchangeable potassium, 0.89 percent for nitrogen and 4.83 percent for organic matter content. In terms of soil physical attributes, the site usually has an average soil depth of 542.68 cm. and soil moisture of 32 percent. In terms of physiographic attributes, the site had an average slope gradient of 7.0 percent, elevation of 257 m asl and position-on-slope of 0.74. Based on the results obtained in this study, it is concluded that site preferences of kawayan tinik growth can be predicted using the following growth indicators such as culm diameter, culm height, clump diameter, number of shoots and culm dry weight