New Nematode Management Options for

Vegetables and Strawberries

Johan Desaeger – GCREC- UF/IFAS

April 12, 2017

5/31/2018

Topics

❖Nematodes in Florida

❖New Nematicide Options

❖Soil Pest and Disease Management

jad@ufl.edu

5/31/2018

Greatest challengesFood security is one of the

of the 21st century.

5/05/2014

3

Source: USDA, FAO, Goldman Sachs Commodities Research

Get more out of every field!

20-40 of potential food production is lost every year to pests.*

%

Impact of Nematodes on Food Production

• Annual nematode crop loss ? $100 billion

globally and $5 billion in US (from 1987)

• Nematode crop loss difficult to estimate > non-

specific symptoms > spotty, stunted, chlorotic

• Significance of nematode crop loss will increase

Root-knot nematodes (Meloidogyne spp. )

• #1 nematode in Florida + the world▫ Global distribution, > 90 species,

mostly (sub)tropical

▫ Infect most crops, vegetables, field crops, root crops, fruits

▫ 50% nematicide use and 5% of overall crop loss

• Endo-parasites▫ enter the roots and disrupt plant

physiology▫ causes root deformation, host and

nematode dependent

• Disease interactions▫ Fusarium, Verticillium, Ralstonia

Meloidogyne incognita distribution

0

5

10

15

20

25

30

35

40

45

50

Market share (% of total nematicide value)

Root-knot nematodes Cyst nematodes Others

Haydock et al, 2006

Sting nematodes - Belonolaimus longicaudatus

• # 2 nematode in Florida▫ Limited distribution

outside FL

▫ #1 strawberry, turf but infects many other crops, vegetables, field crops, root crops, fruits, …

• Migratory ecto-parasite▫ Does not enter root,

feeds from outside

▫ Long spear allows for deep feeding in root tissue

▫ Severely reduces root size

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Nematode Management

Sanitation Crop rotation Biocontrol Solarization

Plant Resistance / Tolerance

Steaming Biofumigation Cover crops

Good agronomy Tillage Chemical

Global Nematicide Sales by Crop, 2011

Source, Kline & Company 2012

5/31/2018

Fungicides, 25.9%

Insecticides, 26.1%

Herbicides, 45.2%

Other, 2.9%

Global pesticide market 2010

Total ~ 44 Billion

Fenamiphos, aldicarb (1960s),

oxamyl (1970s), fosthiazate (1980s)

Chloropicrin (1920), methyl

bromide, 1,3-D, MITC (1940s)

The Ideal Nematicide

Features Grower perspective Regulator perspective

Intrinsic activity Broad-spectrum, controls all parasitic nematodes

Selectivity (safe to non target/beneficial organisms)

Soil behaviour Good soil movement and soil residual activity

No leaching and low soil persistence

Plant behaviour Systemic activity, crop safety

No crop residues, no negative impact on quality

Application Flexibility, low rates Safe to operators, low tox

Compatibility Compatible with other pesticides and fertilizers

Cost Low cost

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New and Upcoming Nematicides

• Fluensulfone (Nimitz™) (Adama)▫ True nematicide▫ Registered in FL

• Fluopyram (Velum™, Luna™) (Bayer)▫ Nematicide/fungicide▫ Nematicide registration FL 2017

• Fluazaindolizine (Salibro™, DuPont) ▫ True nematicide▫ Nematicide registration FL 2018

• Burkholderia sp. (Majestene™) (Marrone)▫ Strain A396, bacterial nematicide▫ Registered in Florida

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1

Fluazaindolizine

How effective is the new nematicide chemistry?

• Root-knot nematode▫ Several years of field trials, overall good efficacy ▫ Tomato/vegetable trials ongoing at GCREC▫ Grower field trials ongoing

• Sting nematode▫ Few trials, efficacy still to be demonstrated▫ Strawberry trials at GCREC and FSGA▫ Grower fields next season

• Different from fumigants and old nematicides▫ Only nematode control

no effect on soilborne fungi and weeds (>< fumigants) no effect on insects (>< Vydate)

▫ Good fit in double crops (via drip)▫ First crop vegetables (strawberries)?

Combined with fumigants, or mixed with soil fungicides and herbicides?

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New nematicides are safer for operatorsChemical Common Oral

LD50 (mg/kg)

Dermal LD50 (mg/kg)

InhalationLC50 (mg/l)

Toxicology Category

Aldicarb Temik 0.5 2.5 <0.01 Danger

Oxamyl Vydate 5 >2000 0.3 Danger

Phenamiphos Nemacur 15 70 0.15 Danger

1,3-D Telone 127 200-500 2.7-3.1 Danger

MITC / AITC V/Kpam/Dominus 72-1000 33-1000 0.21-2.3 Danger

Chloropicrin Several 250 62 < 0.1 Danger

Methyl bromide Several 20-100 15-100 < 0.1 Danger

DMDS Paladin 56-500 >2000 5.2 Warning

Fluensulfone Nimitz 671 > 2000 >5.1 Caution

Fluopyram Velum >2000 >2000 >5.1 Warning

Fluazaindolizine NA > 2000 > 2000 >5.1 TBD

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LD/LC = Lethal Dose / Lethal Concentration

Soil Behavior / Fate

of Nematicides

Crop

RemovalPhoto-

decomposition

Biological

degradationChemical

decomposition

Metabolism

Leaching

Absorption & Exudation

Volatilization

Adsorption

Spray coverage

Capillary

flow

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Physical and chemical properties of nematicides

Chemical name Trade name

Solubility (ppm)

Soil ½ life(days)

Soil behavior

Oxamyl Vydate 280,000 7-14 Mobility very high, residual very short

Aldicarb Temik 5,000 30 Mobility high, residual medium

Fenamiphos Nemacur 400 30 Mobility medium, residual medium

Fluensulfone Nimitz 545 7-17 Mobility medium, residual short

Fluopyram Velum 15 > 200 Mobility low, residual long

Fluazaindolizine TBD 2,000 30-60 Mobility medium +,residual medium +

Fumigants Many Insoluble, volatile

5-50 Mobility medium to high,residual short-medium

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Ecological Effects

Soil

Worms

Soil Micro

Organisms

Soil Macro

Organisms

Sediment

Midge larvae

Surface water

Mammals

and Birds

Fish, daphnia,

algae

Plants

Bees

Arthropods

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Non-fumigants less impact

on “beneficial” nematodes (7 DAP tomato, GCREC, fall 2016)

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0 50 100 150 200 250 300 350 400

Nimitz Half

Nimitz Full

Velum

DCP

Vydate

Check

Kpam

Number per 150 cc soil

Bacterivores Fungivores (P<0.01) Omnivores (P<0.01) Herbivores

Nematodes can be classified into different feeding groups

based on the structure of their mouthparts. (a) bacterial

feeder, (b) fungal feeder, (c) plant feeder, (d) predator, (e)

omnivore.

1%

65%

29%

5%

Herbivores

Bacterivores

Fungivores

Omnivores

New nematicides may improve “soil health” over

fumigants

• Do non-parasitic nematodes benefit crops?

▫ Long-term effect?

• Can we create nematode-suppressive soils?

5/31/2018

How Does It Work? Mode of Action?5/31/2018

Nematicide TargetCrop

Antihelmenthic

methyl bromide general biocide Crop

aldicarb, oxamyl, OPs acetylcholinesterase Crop

abamectin, macrocyclic lactones

chloride channelAntihelmentic /

crop

levamisole, AADs nAChR Antihelmintic

fluopyram succinate dehydrogenase Crop

Fluensulfone, fluazaindolizine

unknown Crop

tioxazafen unknown Crop

New

Seed treatment

Drip irrigation

Drench treatment

Nursery box

Greenhouse

Precision agriculture

How Can the Product Be Applied?More targeted applications

Exactly what is neededWhen it is neededWhere it is needed

Reduced

Worker exposure

Off target risk

Agricultural water use

Application error

Use rate

Investment

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New Nematicides

▫ Less toxic and safer to use – caution label

▫ More selective – true nematicides

▫ New modes of action – or unknown

▫ Different soil behavior – efficacy and application

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Soil behavior of different nematicides

Chemical name Trade name Soil movement Soil residual

Fumigants Many Good- Gas Short

Oxamyl Vydate Good- very soluble Short

Fluensulfone Nimitz Average - Short

Fluopyram Velum Poor- not very soluble Long

Fluazaindolizine Salibro Average + Average

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… Protecting Crops in FL not Just About Nematodes

(Diseases, Insects, Viruses, Weeds)

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Fumigants #1 Nematicide in FL Vegetables

Fumigant Nematode Disease Weed

1,3-D Excellent Poor Poor

Metam (Na, K) Poor-Good Poor-Good

Poor-Good

Chloropicrin Poor Excellent Poor

DMDS Good-Excellent

Good-Excellent

Poor-Excellent

5/31/2018

• Strawberry, tomato, pepper, eggplant

▫ PE-mulched raised beds - double-cropping (cucurbits) common

▫ Drip or seep irrigation

▫ Nearly all fumigated

• Methyl bromide alternatives

▫ Not as mobile in soil

▫ Not as broad spectrum

▫ Longer plant back times

▫ Not as forgiving

• Increasing regulations and restrictions

▫ Fumigant management plans

▫ Buffer zones

(Noling, ENY-06, http://edis.ifas.ufl.edu/in9804)

Fumigant Optimization in Florida5/31/2018

• Soil conditions

• Fumigant selection

• Fumigation equipment

• Fumigant placement

• Tarp selection

• Traffic pan

Drip Fumigation Pro’s and Con’s

• Encouraged by new regulations

▫ Reduces potential for worker exposure

▫ Increases grower flexibility

▫ Allows growers to use same drip lines/mulch for successive crops

• But …

▫ Limited lateral movement in sandy soils

▫ Increased risk of crop injury

▫ Corrosive (pressure valves)

5/31/2018

Cucumber

r = -0.70**

0

2

4

6

8

10

0 0.5 1 1.5 2 2.5 3

Log (ppm 1,3-D +1)

Vig

or

rati

ng

(0-1

0)

Tomato

r = -0.76**

0

2

4

6

8

10

0 0.5 1 1.5 2 2.5 3

Vig

or

rati

ng

(0-1

0)

Movement of Drip-applied 1,3-D in GA and FL Soils(fumigant concentrations using Gastec tubes)

5/31/2018

Tifton, GA, sandy loam Bradenton, FL, sand Quincy, FL, sandy loam

Nutsedge tuber germination, GA Nutsedge control, GA Nematode control, GA

Improving Efficacy of Drip-applied Fumigants5/31/2018

Higher concentration Increase rate Increase irrigation volume

… reduces soil concentration Drip tape configuration … effect on soil concentration

Fumigant + Nematicide Combinations5/31/2018

1,3-D + Vydate Metam sodium + Vydate

Better nematode control Higher yield, esp. 2nd crop

Farming w/o Fumigants … ?5/31/2018

Anaerobic/biological soil disinfestation

Soil steaming Solarization

Non-fumigant nematicides Resistant cv’s Biologicals

Cover crops Biofumigation

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Plant Brassica crop

Mow crop rototill fertilize

Irrigate Plastic beds Plant vegetable crop

Myrosinase

Cell destructionR-C

S

GLuc

N

OSO-3

GLUCOSINOLATES

Glucose + number of toxic compounds

R=NCS Isothiocyanates

MUSTARD OILS

Biofumigation … Fact or Fiction?

Biofumigation … The Good and The Bad5/31/2018

Plenty biomass (winter crop) But Brassica’s often good nematode hosts Mustard decreased RKN levels in pots

But limited effect on RKN ievels in the field As well as on soil pathogens survival Little protection of zucchini in rotation

Intrinsic potency less than chemical fumigants

Poor nematode control in field Soil health benefits

Telone Mustard

Biomass Production and Effect on Root-knot Nematodes of

Biofumigant Crops, Tifton, GA

Treatments Winter crops Cantaloupe

Shoot Root Total G I (0-10)

J2 / 150 cc soil at harvest

J2 / 150 cc soil at plant

GI(0-10)

Marketable yield (lbs)(t/ha)

Mustard Fumus L71 57.0 ab 24.2 c 81.2 bc 2.5 b 58 b 136 ab 6.4 ba 155 bac

Mustard Fumus E75 56.9 ab 14.4 cd 80.2 bc 2.1 b 394 ab 68 ab 7.6 ba 159 bac

Mustard Pacific Gold 41.2 cde 15.6 cd 56.9 cde 1.8 b 422 a 56 ab 6.0 ba 97 c

Mustard Ida Gold 17.8 g 6.2 d 24.0 g 4.3 a 434 a 120 ab 7.9 a 128 bc

Mustard Ethiopian 52.2 bcd 7.8 d 60.0 cd 0.2 c 394 ab 106 ab 7.1 ba 139 bac

Turnip Purple T White Globe 26.7 efg 64.5 a 91.2 b 1.6 b 408 ab 68 ab 6.7 ba 160 bac

Rapeseed Dwarf Essex 37.2 def 12.9 cd 50.1 def 0.2 c 242 ab 80 ab 5.5 b 155 bac

Rapeseed + Rye + Kale 45.3 cde 16.1 cd 61.4 cd 0.3 84 ab 218 a 7.5 ba 138 bac

Rutabaga 30.3 efg 46.5 b 76.9 bc 2.8 b 238 ab 106 ab 6.6 ba 119 bc

Radish White Icicle 59.0 a 45.6 b 104.6 a 5.4 a 80 ab 132 ab 7.7 ba 209 a

Collards 27.8 efg 5.6 d 33.4 efg 0.1 c 176 ab 94 ab 6.2 ba 157 bac

Rye 21.7 fg 7.8 d 29.6 fg 0.0 c 225 ab 30 b 6.5 ba 166 bac

Rye + dazomet 10 b 5.8 ba 195 ba

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Cover Crops

• Grown in rotation with cash crops or in strips within the cash crops

▫ Many options - Brassica’s, leguminous, graminaceous, buckwheat, sunflower, sesame

▫ Cover crop mixtures to reduce risk or increase microbial diversity

• Possible mechanisms:

▫ Trap crop – natural or by terminating crop early

▫ Toxic exudates or breakdown products

▫ Soil food web activity increased

▫ Soil disturbance kills nematodes

• Could be grown in the off season, before or after the cash crop

▫ Improved soil health?

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Resistant Cv’s and Rootstocks

• Root-knot and cyst nematodes

• Single gene and single or few spp.

• Nematodes find a way

• Resistant-breaking races

• Other nematodes fill void

• Increasing number of crops /cv’s with nematode resistance

• Biotechnology – nematicide traits?

Available (target) Underdevelopment

No / little activity

Citrus Bananas Corn

Cotton (RKN) Carrots Strawberries

Peanuts (RKN) Potatoes (RKN)

Peppers (RKN) Rice

Potatoes (PCN)

Peas, lima (RKN)

Soybean (SCN, RKN)

Sweet potatoes (RKN)

Sugarbeet (SuCN)

Tobacco (RKN)

Tomatoes (RKN)

Grapes (RKN)

Prunus spp. (RKN)

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Nematicide Seed Treatments

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Active (2014) Commercial Crop

Abamectin Avicta Cotton, corn,

Thiodicarb Aeris Cotton

Fluopyram Ilevo Soybean

Bacillus firmus Votivo Corn, soybean, cotton, sugarbeet, sorghum

Pasteuria nishiziwae Clariva Soybean

Harpin (N-hibit) Cotton, soybean

Tioxazafen in development

Nematode Research Program GCREC

5/31/2018

• Chemical, biological, combinations with old and new fungicides/herbicides, application technology

New nematicides / New tools to mitigate nematode damage

• Product delivery, placement, bed width, integration with non-fumigant nematicides, site-specific applications

Optimize fumigation practices / application systems

• Nematode-resistant /tolerant crops, compatibility with nematicides• Cover crops and nematicidal crops / biofumigation

Resistance / cultural control

• Nematode survival, distribution, root-knot/Fusarium, weed hosts, suppressive soils, what is soil health

Nematode biology / Nematode-Disease/Weed Interactions / Soil health

• Work with extension staff and growers• Nematode Diagnostics Service • Train nematology students

Extension and Education

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