“[...] if all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we should find its mountains, hills, vales, rivers, lakes, and oceans represented by a film of nematodes…” ~ N. A. Cobb, 1914
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[] if all the matter in the universe except the nematodes ...certifiedorganic.bc.ca/infonews/.../20100307_Rosy_Smit-Nematodes.pdf · – Nematicides • Solarization • Nematicidal
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“[...] if all the matter in the universe except
the nematodes were swept away, our
world would still be dimly recognizable,
and if, as disembodied spirits, we could
then investigate it, we should find its
mountains, hills, vales, rivers, lakes, and
oceans represented by a film of
nematodes…”
~ N. A. Cobb, 1914
Soil Nematodes
Rosy Smit M.Sc. Soil Science (UBC)
Overview
Nematode 101
Management practices and control
Example of current local research to enhance free-living and control plant parasitic species
Summary Resources
Nematode 101
• Microscopic, un-segmented roundworms
• Most abundant multi-cellular life forms on earth (10 to 100 K/L soil) – Most are < 1 mm long
– Occupy soil, aquatic sediments, plants, animals
– Diverse (>25,000 species)
• Free living and plant parasitic
• Plant parasites can cause severe crop losses and damage
Mean M. xenoplax counts for both Tennant’s and Bullpine vineyard sites for four sample dates
under compost and fertilizer treatments.
0
20
40
60
80
100
120
140
fall 07 spring 08 summer 08 fall 08
me
an
rin
g n
em
ato
de
co
un
t /1
00
g s
oil
Bullpine compost
Bullpine fertilizer
Tennant's compost
Tennant's fertilizer
Results
• Soil food web enrichment
Compost increased
• nematode indicators of soil food web enrichment (bacterivores, fungivores)
• nematode indicators of soil food web diversity (omnivores and predators)
but the effect was not long lasting.
• Plant parasitic nematodes
– M. xenoplax and Pratylenchus spp. nematode populations increased in compost amended plots.
Rootstock Microplot trial
Use of rootstocks
• Little is known as to resistance/tolerance of grape rootstocks to Okanagan nematodes
• Research project to compare the performance, resistance or tolerance from 3 selected rootstocks and self-rooted Merlot vines to 2 species of local parasitic nematodes and also combined inoculations
* Rootstocks include Riparia Gloire, 3309C, 44-53M and self-rooted Merlot
Rootstock trial set-up and data collection
• Located at PARC- Summerland • Self-rooted Merlot vines and the
rootstocks planted into 160 – 100 L pots (after fumigation)
• Soil samples twice a year, prune weights and stem diameters yearly
• Treatments – ten pots of each plant type were
inoculated with • M. xenoplax • Pratylenchus spp. • both nematodes • nothing
Mean 2009 pruning weights for three rootstocks and self-
rooted vines inoculated with or without M. xenoplax.
A
A
A
A
B
A
A
A
0
10
20
30
40
50
60
70
44-53M Riparia Gloire 3309C Self-rooted
pru
ne
we
igh
t (g
of
drie
d p
lan
t m
ate
ria
l)
ring nematode
no nematode
Results
• Self-rooted vines showed decline in growth under influence of M. xenoplax after two seasons of growth
• No significant differences in growth of rootstocks
• Other results are forthcoming as the rootstock trial is ongoing…
Other exciting nematode research…
Dr. Tom Forge at PARC-Agassiz
• Impacts of plant-parasitic nematodes on root dynamics and productivity of wine grapes in the Okanagan Valley
• Role of plant-parasitic nematodes in root decline of blueberry
Summary
Soil nematodes are important in agriculture!
• Out of sight, but not out of mind!
• Look at the root systems if plants are unthrifty or unexplained reductions in yield
• Enhance your soil biological system with additions of organic matter
• Use a variety of soil management methods to increase soil health (rotation, cover crops, reduced tillage if possible)
Nematode Testing in B.C.
Soil analysis for nematodes is provided for a fee by:
Plant Diagnostic Lab Ministry of Agriculture and Lands