Resin acid, turpentine, and caloric content of paraquat-treated slash pine

Abstract

Slash pines (Pinuselliottii Engelm.) were injected with 2% paraquat cation (weight/weight basis) and harvested after 24 months. Each stem was cut into three bolts and the amounts of resin acids and of turpentine, the net energy value, and the moisture content were measured. In the lower bolt, adjacent to the treated zone, a 984% increase in resin acids and a 2460% increase in turpentine were found. Averaged over the entire tree stem (three bolts) resin acids increased 407% and turpentine 784%. Moisture content was reduced 53.2% in the lower bolt and 28.4% in the middle bolt and increased 10% in the upper bolt. Turpentine amounts from treated and untreated trees were qualitatively similar and had an average heating value of 10 369 cal/g (1 cal = 4.1868 J). Lower moisture and increased resin of the treated trees increased the caloric content of the lower 152-cm bolt by 33.1% above controls and of the whole tree stem by 12.7% above the controls.