Nematode Control on Peaches and Management of the
Peach Tree Short Life Complex
Fruit Disease Information Note 8 (FDIN 008)
D.F. Ritchie, Plant Pathologist
The following information relates primarily to peaches and nectarines grown in the light, sandy-type soils of the sandhills and eastern North Carolina or in limited areas of the piedmont where these soil types occur. Nematodes and the peach tree short life complex (PTSL) also are most likely to occur in these locations. The information presented below concerns only root-knot and ring nematodes and PTSL management. Consult other Extension publications such as "Growing Peaches in North Carolina" for cultural practices recommended for orchard location selection, preparation and maintenance.
Peach Tree Short Life Complex
Peach tree short life (PTSL) is a disease complex characterized by failure of portions of trees or entire trees to start growth in spring or growth starts and trees or portions of trees collapse usually during bloom or early leaf development. Additional characteristics of this complex are that trees are killed only to the soil-line, usually trees in their third to sixth growing season are most likely to be affected, and is more likely to occur when trees are replanted in locations where peaches were recently grown.
The PTSL complex results from direct and indirect (predisposition) factors. Direct factors, those that can be directly associated with tree death are: freeze injury, bacterial canker (Pseudomonas syringae pv. syringae), and/or the fungus Cytospora. Predisposition factors include such things as ring nematode (Criconemella xenoplax), use of rootstocks other than Guardian, Lovell or Halford, pruning trees before January 1st, and failure to maintain a soil pH near 6.0. Normally, predisposition factors do not by themselves cause tree death, but make the tree more sensitive or susceptible to the direct factors which can cause death. Generally, control of the direct factors is not practical, thus management of PTSL is directed at the predisposition factors.
Preplant Nematode Control
Where root-knot and ring nematodes are present and PTSL has occurred, preplant soil fumigation is an important component for the establishment of a productive orchard. The soil should be fumigated in October to mid-November prior to planting trees the coming winter or early spring. Telon II (1,3-dichloropropene) at the broadcast rate of 30 gallons per acre is suggested. If nematode counts are low and the site has not been planted in peaches for at least 5 years, fumigation of a strip 6-8 feet wide centered where the tree row will be located may provide adequate nematode control. Because several months elapse before planting the trees, the fumigated areas should be marked. This can be done by planting the row middles with a cover crop such as rye or grass intended to be used for sod, then fumigate between these strips. This practice also limits soil erosion and helps prevent the movement of nematode-contaminated soil into the fumigated areas.
Telone II should be applied 10-12
inches deep using chisels spaced approximately 12 inches apart. The soil should be
prepared thoroughly with the surface loose and level. All grass and other plant
debris should have been worked into the soil and be well decayed prior to fumigating.
The soil temperature should be 50-80 F at a 6-inch depth. Soil moisture
should be optimal for planting a crop. A drag or similar type of equipment should be
used behind the applicator to seal the soil surface. Soil fumigants may be sold
under different trade names and may vary in specific recommendations, thus read the label
carefully before using.
Postplant Nematode Control
Currently there are no post-plant treatments available.
Updated July 2007
The information and recommendations in these Notes were developed for
North Carolina conditions and may not apply in other areas.