The effect of fallow on Longidorus americanus, a nematode associated with stunting of loblolly pine seedlings in Georgia, USA
Stunting of loblolly pine (Pinue taeda L.) seedlings, caused by Longidorus americanus, has been a problem at a Georgia (USA) nursery. Field and growth chamber studies were conducted to determine the survivability of the nematode in a fallow nursery soil. The population density of L. americanus decreased rapidly in the upper 15 cm of soil in fallow field plots during the first 101 days and the nematode was not detected after 263 days. Bioassays subsequently failed to detect the nematode in the upper 30 cm of soil in fallow plots on days 263 and 365. Population densities also decreased rapidly in fallow soil during the initial 130 days of the growth chamber study and the nematode was not detected at days 334 and 427, or in subsequent bioassays. Longidorus americanus does not survive well in the upper 15-30 cm of nursery soil in the absence of a host, and the use of fallow may be an acceptable alternative to pesticides for the management of this nematode.