Introducing Nematodes……….
• Nematodes, the most abundant multi-cellular animals on the planet, are unsegmented roundworms.
• They inhabit soil, freshwater and marine environments.
• Most are microscopic.
• Many feed on micro-organisms while some are important parasites of humans, animals or plants.
• Most soil forms are 1 mm or less in length.
• They live in water films around soil particles.

All plant-parasitic nematodes have a hollow stylet or spear

• Cause mechanical injury and death of cells and tissues
• Modify cell development and function
• Alter photosynthate partitioning
• Predispose plants to diseases and other stresses
• Some vector plant viruses
• Stunting, slow growth, dieback
• Chlorosis and nutrient deficiencies
• Wilting
• Reduced yield
• Lack of response to other treatments
• Root symptoms

Many of these are not native species. Why are they there?
Northern Interior/Foothills
Criconemoides xenoplax
…..the importance of nursery certification and clean planting stock
North Coast
Xiphinema index
Criconemoides xenoplax
Pratylenchus vulnus
Central Interior
Meloidogyne spp.
Xiphinema americanum
Tylenchulus semipenetrans
Criconemoides xenoplax
Pratylenchus vulnus
Central Coast
Meloidogyne spp.
Xiphinema index
Criconemoides xenoplax Southern Interior
Meloidogyne spp.
Xiphinema americanum
Tylenchulus semipenetrans
Criconemoides xenoplax

Nematode-free Planting Stock - Nurseries
Dormant cuttings are bench-grafted, callused, and planted in field nurseries or finished in the greenhouse.
• 70% are planted in nematode-free* soil at 10-15 cm spacing, grown for 8-9 months, undercut, and sold as rooted cuttings.
• 30% are planted in sleeves of nematode-free planting medium, healed and established in greenhouses and then sold.
• Hot water treatment at 53°C for 5 min to kill vine mealybug ( Planococcus ficus ) is now an industry standard.
• Coincidentally, hot water treatment at 52°C for 5 min is recommended for nematode-infested nursery material.
• CDFA Nursery Certification Program for nematode-free planting stock is voluntary but most rootstock production is certified
.
*
Nematode-free soil is difficult to find and chemical disinfestation is less reliable as toxic biocides are withdrawn
.
Images: Sunridge Nurseries
Mercier Nursery

Producing Clean Planting Stock
Strategy A.
1. Select soil that is not infested with plant-parasitic nematodes
2. Test soil and plant material after rooting, discard if infested (CDFA certification)
Strategy B.
1. Sites known to be infested or with unknown infestation status
*
**
**
*a. 1,3-dichloropropene 319 + 159 kg/ha (14-day interval) b. Methyl bromide (high density polyethylene film) 336 kg/ha c. Methyl bromide 336 + 168 kg/ha (7-day interval) d. Combinations of 1,3-dichloropropene deep and methyl isothiocyanate superficial
2. Test soil and plant material after rooting, discard if infested (CDFA certification)
Strategy C.
Container-grown in nematode-free sterile media
*
**
*-
Volatile Organic Compound regulations
Volatile Organic Compound and Quarantine/Preshipment criteria (and cost)
Volatile Organic Compound regulations (and poor weed control)

• Preplant management
– Planting site selection, non-host rotation
– Rootstock selection
– Certified nematode-free planting stock
– Preplant soil disinfestation, nematicides
– Clean equipment, water
– Biological antagonists and soil food web health
• Postplant management
– Amendments
– Nematicides
– Cover crops
– Biological antagonists and soil food web health

Breeding and Selection for Broad and Durable Resistance a 15-year process

Genotype
101-14Mgt
1103Paulsen
110Richter
140Ruggeri
1613Couderc
1616Couderc
3309Couderc
420A
44-53Malegue
AxR1
Borner
Dog Ridge
Freedom
Harmony
K51-32
Kober 5BB
Ramsey
Riparia Gloire
RS-3 hferris@ucdavis.edu
Parentage
V. riparia, V. rupestris
V. solonis x V. riparia
V. berlandieri, V. rupestris
V. berlandieri, V. rupestris
V. solonis, V. othello
V. solonis, V. riparia
V. riparia, V. rupestris
V. berlandieri, V. riparia
V. riparia, V. cordifolia, V. rupestris
V. vinifera, V. rupestris
V. riparia, V. cinerea
V. champinii
V. champinii, V. longii, V. vinífera,
V. riparia, V. labrusca
V. champinii, V. longii, V. vinífera,
V. riparia, V. labrusca
V. champinii, V. rupestris
V. berlandieri, V. riparia
V. champinii
V. riparia
V. candicans, V. riparia, V. rupestris
R
S
R
R
R
MR
R
R
R
S
R
R
R
R
R
R
S
MR
MR
S
MR
S
R
S
S
R
S
S
S
S
R
S
R
MR
S?
MR
S?
S
S
MR
S
MS
S
S
S
S
S
S
R
S
R
MR
MS
S
S
MS
MS
S
MS
MS
S
MS
S
S
S
S
S
S
S
S
MR
S
S
S
MS MS
MR
S
S
S
MR
MS
S
S
MS S S S S S
MS
S
MR
R
S
S
S
S
S
S
R
MS
MS
MR
MR
S
MS S http://plpnemweb.ucdavis.edu/Nemaplex
S
MR
S
S
S
S
S
S
MS
MS
MR
S
S
S
S
S

Genotype
RS-9
Schwarzmann
St. George
Teleki 5C
USDA 10-17A
USDA 10-23B
USDA 6-19B
VR O39-16
UCD GRN1
UCD GRN2
UCD GRN 3
UCD GRN4
UCD GRN5
Parentage
V. candicans, V. riparia, V. rupestris
V. riparia, V. rupestris
V. rupestris
V. berlandieri, V. riparia
V. simpsoni, M. rotundifolia
V. doanianna
V. champinii
V. vinifera, M. rotundifolia
V. rupestris cv A. de Serres, M. rotundifolia cv Cowart
V. rufotomentosa, V. champinii cv
Dog Ridge, V. riparia cv Riparia
Gloire
V. rufotomentosa, V. champinii cv
Dog Ridge), V. champinii cv c9038,
V. riparia cv Riparia Gloire
V. rufotomentosa, V. champinii cv
Dog Ridge), V. champinii cv c9038,
V. riparia cv Riparia Gloire
V. champinii cv Ramsey, V. champinii cv c9021), V. riparia cv
Riparia Gloire hferris@ucdavis.edu
R
S
S
MS
R
R
R
S
R
R
R
R
R
R
MR
MR
R
R
R
S
R
S
S
S
R
R
MS
S
R
R
R
R
R
R
R
R
R
S
MR
S
MR
R
R
MR
R
R
S
MS
S
MS
MS
MR
MR
R
R
MS
S
MS
S
R
R
R
MR
MR
S
S
R
R
R
S
R
MS
S
R
MR MR
MR
S
S
MS
MS
R MS MR MS
R MR MR MR
R MR MR MR
R
MR
MR
MS
R MR MR MR http://plpnemweb.ucdavis.edu/Nemaplex

finding the information…….
Nemaplex: http://plpnemweb.ucdavis.edu/nemaplex

Postplant Nematode Management
• avoid introducing nematodes on equipment, people, water
• water and fertility management appropriate to root system
• increase organic matter for soil structure, water-holding capacity, nutrient value and to build soil food web
• winter cover crops for soil building and nematicidal effects
Enzone (CS
2 liberator) applied in irrigation water [ectoparasites +++, endo ?] (Arysta LifeScience)
DiTera (antibiotic) applied in irrigation water - drip or furrow - 20 lb per acre three times per year
[ectoparasites ++, endo ?] (Valent)
Movento ( spirotetramat) a lipid biosynthesis inhibitor with systemic activity – applied by foliar spray [ectoparasites ++, endo ++] (Bayer CropScience)
•Notes: chemical nematicides may disrupt food web structure and function nematicide rotation to delay loss of efficacy

From Nemaplex : Cover crops for soil building………..
Some plants resistant or immune to Xiphinema index …..
Nemaplex – http://plpnemweb.ucdavis.edu/nemaplex

Commercial Soil Amendments
…for nematode management and soil health
Farewell
Microlife
Microplex
F-68 Soil Conditioner
Clandosan 618
Superbac
Agrosyn
Guano Plus
Quinoa
Sesame
Humic acid
Compost
Agri-50
Pent-a-vate
Arise
Fertilaid
Zap
Ammonium sulfate
Ozone
Probiotic
…….and more
Potential Modes of Action
• Contain beneficial microbes
• Stimulate or provide resources for antagonists
• Reduce plant stress (improved soil structure, moisture retention, plant nutrition)
• Nematicidal breakdown products
• …..and sometimes……no effect

Soil Bacteria
Protozoa
Soil Nematodes
Soil Microarthropods

Biological antagonists of nematodes

Economies of Ecosystems: Carbon and Energy are the Currencies
CO
2
CO
2
CO
2
CO
2 carbohydrates and proteins bacteria protozoa nematodes carbohydrates
C and amino acids
N nematodes nematodes arthropods fungi other organisms
NO
3 fungi
Carbon and energy transfer arthropods organisms in the food web
NH
3
NH NH
3
Energy available limit the size and activity of the web

Food Web Complexity and the
Regulation Function
Management practices in industrialized agriculture result in:
Soil food web simplification
Reduction in higher trophic levels
Costa Rica, 2008