Stunting of Southern Pine Seedlings by a Needle Nematode (longidorus Sp.)

An undescribed needle nematode (Longidorus sp.) was consistently associated with stunted loblolly pine seedlings at the Flint River Nursery in south Georgia. Seedlings in affected areas had root systems that were greatly reduced in size, and lacked lateral and fine roots. In a growth chamber experiment, the needle nematode significantly reduced the size of loblolly pine root systems in containers initially infested with 100 and 200 nematodes. Populations of the needle nematode increased in all containers during the course of the experiment. Slash and longleaf pines have also been found to be hosts for the needle nematode. Cover crops typically used at the nursery, including sorghum, wheat and rye, were not found to be hosts. Yellow nutsedge was also not a host. A survey conducted in pine seed orchards that border the nursery indicated that 37% of the soil samples were positive for the needle nematode. The nematode was not found in redcedar windrows, an oak seed orchard, and pine stands adjacent to the nursery.