Pitch Canker Impact on Volume Growth: A Case Study In Slash Pine Plantations

Abstract

Abstract Measurements from 26 permanent test plots established in slash pine (Pinus elliotti var. elliotti Engelm.) plantations of northeast Florida and southeast Georgia in 1976 have been used to assess the impact of pitch canker on growth and yield of trees over time. The plots were remeasured annually for five years. The mean annual volume increment for infected trees was between 60 and 81 percent of that of the healthy trees. Trees that were repeatedly infected grew proportionately less, over the five-year period, than those that were infected only once or twice. The five-year periodic volume increment for the most severely infected trees was between one-third and two-thirds of that of healthy trees in the same diameter class. Incidence of infection was not correlated with tree diameter. The overall cubic foot volume loss due to growth suppression and mortality amounted to 4.5 percent of the expected total volume in 1981. This loss represents 15 percent of the anticipated five-year volume growth.