ESTIMATING FOLIAGE AREA OF LOBLOLLY-PINE SHOOTS

In this study, foliage surface area of loblolly pine (Pinus taeda L.) shoots from plants grown in a 2 x 2 factorial study of nutrients and w ater and three levels of CO2 was predicted by flush (growth cycle). Ha rms (1971) predicted foliage surface area of a flush from the weighted product of foliated flush length and average needle length, In the pr esent study flush foliage surface area was predicted using the product of the natural log of foliated flush length and average fascicle leng th, and an additional independent variable fascicle density, Equations generated for each of the whole-plot treatment combinations did not d iffer significantly, therefore one prediction equation was developed f or all whole-plot treatment combinations, Flush location significantly affected prediction of flush foliage area, therefore separate equatio ns for predicting flush surface area were developed for the main and l ateral shoots, The equations explained 96% of the variation in predict ing flush foliage surface area for both main and lateral shoots with f ascicle density explaining an extra 12% of the variation, The equation s predicted flush foliage surface area with an average absolute percen t deviation of predicted values of 16.1% and 12.6% for the main and la teral shoots.