Author : Rosario, Joselito I.

Summary : The study was undertaken to generate information that could help in the effective management of the natural stands of kawayan tinik in Ilocos Norte for sustained production of poles and shoots. Representatives towns and barangays were selected from the two geographic zones of the province. Sample clumps were selected in four physiological locations in each representatives barangay. Clump characteristics, including some edaphic and physiographic variables in each sampling location, were measured. Variations in clump characteristics were assessed using analysis of variance, while multiple regression analyses were made to ascertain the variables for predicting shoot, culm and biomass yields of clumps. Clumps in the northern towns (District I) of Ilocos Norte produced taller and stouter culms, taller shoots and higher stem biomass yield than those found in the southern towns (District II). The clumps found in the northern towns of the province are more productive because of higher average annual rainfall, soil OM and K contents. On the other hand, clumps along creeks had the biggest diameters, and the highest culm and biomass yields while those on hilly areas have the smallest diameters, and lowest culm, shoot and biomass yields. Clumps along creeks have better yields due to the interrelationships for more favorable site factors such as availability of moisture, moderate slope, lower elevation and better soil characteristics. The multiple regression analysis showed that clump diameter is an important factor in predicting the shoot, culm and biomass yields of natural stands of kawayan tinik. In addition, the edaphic and physiographic factors (like aspects, slope, elevation and soil pH, OM, P and K) helped improved the equations for estimating the yield of the stands. The information on the location of more productive stands can be used as basis in crafting management schemes for kawayan tinik in the province. For instance, rehabilitation of old stands along creeks can be priotized since these clumps are more productive and could help meet the current and projected demand for poles and shoots. On the other hand, the developed equations can be used in estimating the shoot, culm and biomass yields of natural kawayan tinik stands growing on the various physiographic locations in Ilocos Norte.