Pitch Canker Disease of Loblolly and Pond Pines in North Carolina Plantations

Abstract

var. subglutinans were present on dead Kuhlman, E. G., and Cade, S. 1985. Pitch canker disease of loblolly and pond pines in North branches. The disease, present on 39% of Carolina plantations. Plant Disease 69: 175-176. the 2,760 trees, was widespread; individual diseased trees were available in all areas Pitch canker disease, caused by Fusarium moniliforme var. subglutinans, is reported for the first for the growth study. Dieback in this time in plantations of loblolly (Pinus taeda) and pond pine (P. serotina). In 1983, pitch canker plantation affected only the current year's caused a high incidence of dieback on plantations in eastern North Carolina. Loblolly pines with growth and did not extend farther down terminal dieback were smaller in both height and diameter than healthy trees, whereas only pond th an did n te grth down pines with severe terminal dieback were shorter but not smaller in diameter than healthy pond the mai sm ntowth studylarea, pines. 67% of the 320 randomly selected loblolly pines. pines had dieback. Height and dbh of healthy loblolly pines were significantly Pitch canker disease of southern pines dieback; 2,760 trees were tallied, larger than those of diseased loblolly causes dieback of the terminal and upper The effect of the disease on height and pines (Table 1). lateral branches of loblolly pine (Pinus diameter growth was determined in a In the pond pine plantation, 45% of the taeda L.) in seed orchards (5-7). Pond 0.675-ha plot for each species. Within 320 randomly selected trees had terminal pine (P. serotina Michx.) seedlings were each plot, 320 individuals were randomly dieback. Isolates of F. moniliforme var. susceptible to infection by Fusarium selected for assessment of the presence or subglutinans were obtained from 28 of 30 moniliforme Sheld. var. subglutinans absence of terminal dieback. Trees were pond pine branches with dieback; this Wollenw. & Reink. in a greenhouse assigned to healthy or diseased (lightly- confirms the association of the fungus inoculation study, but both pond and and severely diseased in pond pine) with this host. Two types of damage loblolly pines were rated less susceptible categories. For growth measurement, occurred in the pond pine: 33% of the than Virginia (P. virginiana Mill.) or equal numbers of trees in each disease trees had light damage with only the slash (P. elliottii Englem. var. elliottii) category were selected on the basis of the youngest terminal growth affected, and pines (2). This paper reports the priority established in the random 12% of the trees had severe damage with occurrence and severity of pitch canker number selection. For growth assessment, dieback extending at least 0.6 m down the disease on loblolly and pond pines in the height to the top of the live crown and main stem. Healthy pond pines were not