1. Collecting. If a large area in an orchard is
   believed to be involved, collect samples from the
   edges of the affected area. Take a mixture of roots
   and soil from at least 10 separate sites at depths
   of 12 to 15 inches. Collect at least 1 quart of
   soil. Send only a single blended sample from an
   orchard. Do not mix samples from several
   orchards.
   A brief history of the affected area will be helpful
   to the nematologist when he or she makes the
   diagnosis.
2. Handling. After collecting, place sample in a
   plastic freezer bag and close the bag tightly to
   prevent drying out. It is not necessary to add
   water to a freshly collected soil and root sample.
   Protect the sample from high temperatures and
   from freezing.
3. Submitting. Enclose with the sample a letter
   that gives the following information:
1. date sample was collected
2. crop from which sample was collected
3. name and address of grower
4. name and address of person submitting
   sample
5. description of plant symptoms
6. crop to be planted

Growers should contact their county agent for a
fact sheet for submitting samples to the PLANT
DIAGNOSTIC LABORATORY. All samples should be
marked "For Nematode Detection."A reply will be sent
as soon as possible, usually in about 10 days.

Controlling. Plant-parasitic nematodes are always a
problem where peaches follow peaches. In some
instances, they can also be troublesome in sites where
peaches have not been grown previously. Where
nematodes are troublesome, trees do not grow as
vigorously. Further, nematode feeding increases the
incidence of peach decline, and it can increase the
incidence of stem pitting.
Preplant nematicide treatments are necessary to
promote tree vigor and to prevent the replant problem.
Postplant treatments are necessary to reduce tree loss from
peach decline and stem pitting.
Research has shown that nematodes build up and reach
damaging levels by the end of the second growing season
when fumigant-type nematicides are used. The nematode
buildup may occur at the end of the first growing season
with nonfumigant-type nematicides. Research results
indicate postplant nematicide treatments are needed yearly
to prevent tree loss.

Fumigant-type Nematicides. Fumigant-type
nematicides have been used successfully for many years.
Growth response of peach trees to soil fumigation has
consistently been recorded where nematicidal rates of soil
fumigants were employed. In some instances, an
additional growth response was recorded where disease
control rates of soil fumigants were employed. Below are
the recommended materials and rates.

110

1998 New Jersey Commercial Tree Fruit Production Guide