August 2021 - 17

SOLVING THE PARASITIC NEMATODE
PROBLEM: A PREVENTATIVE APPROACH
W
hen growers redevelop an orchard,
it's imperative that certain steps
are taken to ensure fast growth and
plant health. Ultimately, it's difficult to control
what happens in an open orchard setting, but
by properly preparing the soil, growers can
expect that many potential problems will be
mitigated, resulting in better long-term results.
The Problem
Since nematodes and other potentially
pathogenic organisms can be found not just
in the top layer of soil, but also within several
feet of depth, it's difficult to adequately treat
the soil using conventional methods; this often
results in often patchy protection. Nematode
hot zones may be visible in existing orchards
and are indicated by uneven growth, in absence
of other causes. Preventing these hot zones can
help ensure that fertilizer and water are not
wasted due to underuse.
With the added variable of how long roots
can survive and provide shelter and food for
those organisms, and with estimates up to
several years, it takes the right soil treatment, in
addition to the correct preparation, to net the
results growers need from their young orchards.
Recommended IPM Strategy for young
orchards
Uniformity throughout an orchard helps improve
efficiency of growth, fertilizer and water use,
and a consistent harvest. Using an integrated
pest management strategy can alleviate the
problems associated with a lack of uniformity in
the orchards. These steps will set up an orchard
for better success - with faster growth.
1. Test the soil. Take samples, especially
in areas where there were patchy spots,
and send them to the local university or
nematology lab for testing; this will provide
a window into the nematode pressure in
the orchard.
2. Deep Rip. After removing retired trees from
the orchard, using a backhoe to fracture
the soil up to six feet deep and to the sides
helps to generate a growth response in
new trees, according to a Merced County
university study.
3. Remove old roots. Take the time to
remove old roots as soon as possible. The
pest populations will start to dissipate as
soon as infected roots are removed. Allow
as much time as possible between root
removal and fumigation.
4. Thoroughly till soil. Break up the clumps
and clods, preparing the soil not only for
UNTREATED CONTROL
young roots but also to allow fumigant to
fully permeate the full volume of soil that
will be treated. This will also assist the soil
as it seals at the surface.
5. Fumigate. Use a pre-plant fumigant such
as Telone®
II in a broadcast application,
which can help prevent future hotspots.
Another option, in orchards where there
is a known fungal or bacterial problem,
is to use a Telone/Chloropicrin blend at
this step. " Growers have to make critical
decisions whether to do strip vs. broadcast.
However, when there is nematode pressure
within a field, the pressure can be found
between the tree rows, and over time
the pressure can move. Once rootstock
is planted, plant parasitic nematodes can
sense root exudates and move towards
the root system to feed, causing infection.
If a grower cannot do broadcast, it is best
to follow up with post treatment contact
nematicides through the seasons to help
reduce nematode infection, " said Kristi
Sanchez, Ph.D, Nematologist for TriCal
and TriCal Diagnostics. For best results,
fumigation should be done in the fall.
6. Plant cover crops. Choose a crop that
is not susceptible to nematodes but
which also has a long root. A crop such
as safflower will help to dry out the soil,
desiccating any surviving nematodes in
preparation for planting trees.
7. Choose the right root stock. Consider
resistant or tolerant roots that will not be as
susceptible to nematodes; this is especially
important in areas where nematode
pressure was high, based on the soil testing
performed at the start of the process.
8. Ongoing IPM strategy. Fumigation isn't
possible after planting, but it will give your
TELONE II WITH CHLOROPICRIN
orchard a fighting chance. Continuing to
manage nematodes is important to keeping
that advantage the orchard will get from
the careful preparation and fumigation.
Trial results with Telone fumigation
" Telone is a key step in a multistep IMP strategy
to give growers the best shot at suppressing
nematodes and maintaining healthy orchards, "
Sanchez said.
In trials, Telone fumigation prior to planting
has resulted in significant increases in trunk
diameter, tree height and overall canopy size
compared to untreated trees. The field trials
being conducted by the University of California
have initially shown a cumulative yield increase
of 80% over trees not treated with Telone,
measured from 2013 through 2018. In the trial,
planting was done in 2011 in treated sandy soil
that previously had heavy nematode pressure,
including ring, lesion and root knot nematodes.
About Telone II
Telone II soil fumigant is a preplant soil fumigant
for control of all major species of nematodes,
including root-knot, lesion, stubby-root, dagger,
ring and cyst. Telone II is injected into the soil
as a liquid and immediately converts to a gas,
creating a zone of protection around developing
roots. As a fumigant, Telone moves throughout
the soil profile without requiring water or
incorporation for movement. Learn more about
Telone at www.teleosag.com.
®™Telone is a trademark of The Dow Chemical
Company. Telone is a Federally Restricted Use
Pesticide. Always read and follow label directions.
ADVERTISEMENT | © 2021 Teleos Ag Solutions
http://www.teleosag.com
August 2021

Table of Contents for the Digital Edition of August 2021
