Robert Woolley Dave Wilson Nursery Hickman, CA

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Robert WoolleyDave Wilson NurseryHickman, CA

• growers of deciduous fruit, nut shade trees
• for commercial growers
• the home garden

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Dave Wilson Nursery

• primarily field-grown, trees sold bareroot
• some stock grown in containers
• 1 to 2 years in ground
• zero tolerance for nematodes

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Dave Wilson Nursery

• trees sold to commercial growers must be produced
  under CA Dept of Food Agriculture (CDFA)
  Nematode Certification Program
• CDFAs Nematode Certification Program requires
  soil treatment or nematode sampling
• soil treatment must eliminate nematodes to 4 to 5
  feet deep, for 1 to 2 years

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• 3 soil treatments used in CA for control of
  nematodes in field grown deciduous trees

• methyl bromide with chloropicrin
• Telone II (1,3-dicholoropropene)
• Vapam (metam sodium)

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methyl bromide

• only soil treatment effective in heavy soils
• only nematicide in general use that
• also effectively controls weeds
• granted limited use in CA nurseries by Montreal
  Protocol, under QPS exemption
• rates of chloropicrin from odorant to
• as high as 33 (strawberries up to 50 pic)
• a biocide, so it disrupts soil ecology

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Telone II

• approx 95 of CA tree nursery Telone II
  treatments are done under tarp--tarping may
  provide some weed control
• use limited by township caps
• 30 days (minimum) to plant back
• putatively more benign to soil ecology than
  methyl bromide

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Vapam

• requires water as carrier to target pest,
• but sprinkler application limited as its
• highly volatile
• drip application impractical in nurseries
• very limited use with Telone II due to
• cumbersome application rig

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non-chemical alternatives
crop rotation and/or extended fallow -maybe
OK--limited by time required mechanical
(super-heated water/steam) -questionable
efficacy cost? Star Wars devices -cost?
soil ecology concerns
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other alternatives
methyl iodide -little to no interest due to
phytotoxicity propargyl bromide -tends to
explode Nemacur, Vydate Furidan (sp?)
-registered for use in CA via drip but not
used due to impracticality brassicas other
veges -insufficient nematode kill
-impractical
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next steps?

• plant breeding for immunity
• -very long term but important to
• pursue
• novel approaches to killing nematodes
• and controlling weeds disease
• -new chemicals?
• -genomics?
• Grow trees solely in containers
• -the ultimate solution?