organic vegetable production outline level 2 master ...€¦ · 6 squash bug, anasa tristis...

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Organic Vegetable ProductionLevel 2 Master Gardener Volunteer

Training - March 5, 2013

Erin Silva

Organic Production Scientist

Dept. of Agronomy

1575 Linden Dr.

Madison, WI 53706

(608) 890-1503

[email protected]

Outline

• Overview of organic agriculture

• Pest management principles

• Insect management

• Disease management

Distribution of Organic Farms Growth of Organic Agriculture

• U.S. organic food sales have grown between 8-21% each year since 1997 (total U.S. food sales over this time have grown in the range of 2 -4% a year)

• Organic food sales represent approximately 4% of U.S. food sales

Certified Organic vs. ‘Produced with Organic Methods”

Organic Production Standards

Organic agriculture is “a production system that is managed in accordance Organic Production Standards with the Act and regulations in this part to respond to site-specific conditions by integrating cultural, biological, and mechanical practices that foster cycling of resources, promote ecological balance, and conserve biodiversity.”

~USDA ORGANIC DEFINITION

ES1

ES1 Erin Silva, 9/18/2009

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Organic Production Standards• Land is certified by gov’t-

approved agencies• Farmer develops and follows

organic farm plan• Synthetic substances

prohibited• Natural substance allowed• Production methods

– Enhance soil and biodiversity

• Separation from conventional products– In time – 3 year transition

period– In space – buffer zones,

barriers, separate– containers, equipment

cleaning etc.

Certification:Who can use the word “organic”?

• >$5,000 annually?– Must certify.

• <$5,000 annually?– May certify

– must follow standards

– subject to audits (NOP pays)

• Misuse of “organic”– $10,000 fine

Organic Seed andTransplants

• Expect 20% price premium

• Organic transplants increasingly available

• No wetting agents or synthetic fertilizer in potting mix

Organic Fertilizers

• Organic fertilizers available– Bone meal, blood

meal, soy meal, fish meal, compost

• Vary in N-P-K • Vary in nutrient

availability• Vary in cost

Soil Fertility: Compost

• No pre-harvest interval

• Strict requirements for manure-based compost– 131-170°F for 15 days

in windrows

• C/N = 30:1

Site specific conditions

• Not a cookbook

• Organic pest management plans reflect unique characteristics of each operation

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Organic Pest Management:Emphasizes Preventative

Practices

1st Phase Strategies(Foundation of Organic Pest Management)

• Cultural practices implemented in the initial stages of organic farm planning

• Prevent and avoid problems beforehand

• Has foundation in “IPM”

Second Phase StrategiesVegetation Management

• Make habitat less suitable for pests; attractive to natural enemies

• Habitat enhancement

• Ecological engineering– Habitat for natural enemies

– Intercropping

– Trap Cropping

Plant Diversification

• Provides food and shelter for natural enemies (predators and parasites)– Favorable microclimate

– Alternative hosts or prey

– Supply of nectar and pollen

• Enhances “top-down”action of natural enemies on pests.

Flowering Insectary Strips

• Provides pollen and nectar

• Attracts and keeps natural enemies in area

Chocolate-box Ecology?

• Flowering plants added without prior testing

• Parasitic wasps visit an average of only 2.9 plant species

• Researchers now screen plants for optimal species

• Farmers collect info on key pests, natural enemies to design effective farmscapes

• www.attra.org

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Third Phase StrategiesRelease of Biological Control

Agents• Predators, parasitoids

• Microbial agents

• Selectivity

• Allow for rapid response to pest problems

• Most research in greenhouse systems

4th Phase Strategies

• Insecticides pheromones

• Repellents

• Mineral oils, insecticidal soaps

• Allowable chemical pesticides

Limits of NOP-Approved Insecticides

• Degrade quickly• Low potency• Short residual activity

– Must integrate with other strategies

• Spray in evening, on cloudy days– Degrade in sunlight

• Need to take account mode of action– Does it need to be applied to the insect?

Does the insect need to eat it?

Organic Insect Control ProductsCurrent Trends in Organic Farming

• Reduced pyrethrin use; non-target effects

• Azadirachtin (neem) use is increasing – Successful experiments against several pests

including aphids and some chewing insects

• Spinosad one of few new approved materials– Fermentation product of bacterium

Saccharopolyspora spinosa

– Successfully tested worldwide against a variety of pests/crops

Bacillus thuringiensis (Bt) spores can be formulated as dusts or sprays and have been

used for years as “natural” insecticides.

Spores of Bt are dusted on vegetables by home gardeners and organic producersor sprayed (1000 spores per sq meter) to kill

larvae of lepidoptera (e.g. corn ear worm)

Pyrethrum is a non-synthetic

insecticide (botanical)

Pyrethrum is extracted from the flowers of the chrysanthemum grown in Kenya and Ecuador. It is one of the oldest and safest insecticides available. The ground, dried flowers were used in the early 19th century as the original louse powder to control body lice in the Napoleonic Wars. Pyrethrum acts on insects with phenomenal speed causing immediate paralysis, thus its popularity in fast knockdown household aerosols. However, unless it is formulated with one of the synergists, most of the paralyzed insects recover to once again become pests. Pyrethrum is a mixture of four compounds: pyrethrins I and II and cinerins I and II.

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Azadiracthin

Azadirachtin, an allelochemical from the Neem tree that is an anti-feedant and can be used as a spray. Plants contain tens of thousands of chemicals, most of which have not been identified let alone studied. Their role is in plant-plant or plant-herbivore interaction is poorly understood.

Spinosyn

S. spinosa was isolated from soil collected inside a non-operational sugar mill rum still in the Virgin Islands. Spinosad has high efficacy, a broad insect pest spectrum, low mammalian toxicity, and a good environmental profile

Insecticidal Soap

Potassium fatty acid soaps used to control many plant pests. Insecticidal soap is typically sprayed on plants in the same manner as other insecticides. Insecticidal soap works only on direct contact with the pests. The fatty acids disrupt the structure and permeability of the insect cell membranes. The cell contents are able to leak from the damaged cells, and the insect quickly dies.

Organic Management of Insect Pests

Insect pests - cucurbitsCalendar of Insect Pests – Cucurbit

Crops

April May June July Aug Sept Oct

April May June July Aug Sept Oct

Aphids

Cucumber Beetles

Squash Bug

Squash Vine Borer

Seed maggots

Pickleworm

Whiteflies

Leafminers

Mites

ThripsThrips

Flea beetles Flea beetles

Courtesy of R. Groves, 2013

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Squash bug, Anasa tristis

Occurrence• Adults are large black bugs

which aggregate on plants

• Round eggs are laid in neat rows

• Nymphs are white/grey

Damage• Phytotoxic saliva causes wilting

• Cucurbit yellow vine decline- Hubbard and winter squash

more severely affected


Squash bug - Management Thresholds

Seedling Stage

• Treat if wilting and squash bugs are observed

Flowering Stage

• Treat if > 1 egg mass is found per plant

Control

• Foliar insecticides (pyrethrum)• Cultural:

- sanitation – remove overwintering sites- destroy crop residue

Squash bug egg mass


Squash Vine Borer

Occurrence• Adults are diurnal, wasp-like moths

• Lay eggs singly on vines

• Larvae bore into plants and destroy vascular tissues = wilting and death.

• Not a pest of watermelon, muskmelon, or cucumbers

• Emerging issue on winter squash (Hubbard) and pumpkin

• Occasional second generation

Adult moth

Larvae


Squash Vine Borer Control

Sampling

– Field history: past problems = future problems

– Often more serious in smaller plantings

– Direct observation = entrance holes & frass

Cultural

– Practice good field sanitation

– destroy residue

Chemical (re-application)– Pyrethrum (Pyganic)

– Bacillus thuringiensis var. ‘kurstaki’

– **Note: directed application to the first 12-16” of vine


Occurrence

Usually occur in hot dry conditions

More severe in dusty, road side locations

Multiple generations on undersurface of

leaf

Two-spotted spider mites, Tetranychus urticae

Damage

Adults feed in large numbers on

leaf surface causing “silvering”

Lower surface often covered with

webbing

Late season pest

Can be ‘flared’ by pyrethroids Courtesy of R. Groves, 2013

Cultural

Maintain good plant growth, irrigate

Avoid dusty roads

Biological

Several effective predators

Avoid broad-spectrum insecticides

Chemical

Unless necessary, do not use

‘Hormoligosis’: boosts egg production

Insecticidal soap

Spider mite, ManagementLeptothrips

Minute pirate bug


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Striped cucumber beetle(Acalymma vittatum)


Striped and Spotted Cucumber Beetles

Lifecycle• Adult beetles 8-10 mm length

and 3-4 mm wide

• Striped cucumber beetle Acalymma vittatum

• Spotted cucumber beetleDiabrotica undecimpunctata

• Striped cucumber beetles overwinter in protected areas as adults and become active in mid-spring.

• Appear early, lay eggs at the base of cucurbits, and have 2 generations / year

• Striped is most severe

Spotted cucumberbeetle

Striped cucumberbeetle


Cucumber Beetles: Damage

Defoliation Pollination Interference

Feeding Scars Rindworms


• Most damage is from bacterial wilt, Erwinia tracheiphila

• Closely associated with beetle, vectored via posterior-station

• No cure for bacteria, control through vector

• Susceptibility:

Melons (not watermelon) > cucumbers > butternut and Hubbard squash

Cucumber Beetles – Bacterial Wilt


• Avoidance of bacterial wilt is accomplished through effective cucumber beetle control.

• Sampling can be accomplished with yellow sticky traps

• Established Thresholds (direct counts):

1 beetle / plant for melons, cucumbers, andyoung pumpkins

5 beetles / plant for watermelon, squash,and older pumpkins

• Pyganic an organic option

Management – Bacterial Wilt


Cucumber beetles: Management

Cultural– Later planting (June 10 – 15)– Transplants– Trap crops on plastic mulches

Black plastic

Blue Hubbard


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Cucumber beetles: ManagementCultural

– Eliminate weeds, weedy edges (sanitation) –pollinators

– Crop rotation– Early season row cover

Floral Nectaries

Row cover

Close mowing


Row Covers

• Flexible transparent material

– Perforated plastic, spunbonded polyester – polypropylene

• Floating or supported by hoops

• Can cover one or more rows

• Think of crop needs when deciding on type of row cover – temperature needs, pollination, growth habit

Supported Row Covers

• Also called Low Tunnels

• Can use PVC pipe, heavy wire

• More labor needed

• More for season extension than insects

Cole Crops - Insect Pest ComplexDiamond back

mothImported cabbage

wormCabbage looper

Cabbage maggot Flea beetle Cabbage aphid

Sporadic Pests


History of problem– Direct damage to marketable product by key pests

• Worms on heads

• Maggots on roots

– Multiple insecticide applications used

– Resistance developed as threat to production

Solution– IPM implementation based on biological control of key pests

– Pesticides switched to specific, ‘soft’ materials to preserve natural control

Managing Insects on Cole Crops


Adult•Small night flyer, short fast flights•½”, wings have diamond pattern•Can monitor with pheromone trap

Eggs•Small, hard to see•Laid close to veins

Larvae•4-5 instars up to ¾” long•2-3 weeks•Cigar shaped, pointed at ends•‘wiggle’ when touched•Spin thread and hang

Pupa•Usually on underside of leaves•Neatly spun pupal case

Diamondback moth life cycle


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Diamondback moth

Occurrence– Does not overwinter in Wisconsin

– Blown in on wind or imported on plants

– 4-8 generations per year

Damage– ‘Window pane’ feeding, may also deform

heads

– 1st instar mine in leaf

– Damage usually early-mid season

(June/July)

– Resistance to many insecticides

– Major problem worldwide Courtesy of R. Groves, 2013

Imported Cabbage Worm life cycle

Adult•White, day flying butterfly

Eggs•Laid single on undersurface•White, turning yellow at hatch•Cigar shaped

Larvae•5 instars; 3-4 weeks•Velvety green with yellow dorsal line•Slow moving•Up to 1 ½ inches in length

Pupa•Distinctive angular shape•Usually on plant debris/old leaves


Imported Cabbage Worm

Occurrence– Overwinters as pupae in Wisconsin– 3 generations per year, 1st on weeds

Damage– Usually most damaging species in

Wisconsin– Large holes in leaves and heads– Often extensive frass– Peak damage mid-season

(June/July)


Cabbage Looper life cycle

Adult•Large, night flying moth•Hour glass marks

Eggs•Laid singly on undersurface•White, turning tan at hatch•round shaped

Larvae•5 instars; 4-5 weeks•Green with white stripe•Loop when moving•Up to 2 inches in length

Pupa•Roughly spun silk cocoon•Underside of old leaves or on debris


Cabbage Looper

Occurrence– Does not overwinter, adults blow in

(June/July)

– 2 generations per year, persisting in late season

Damage– Damage usually late season

– Extensive leaf holes and

head damage


Managing the Caterpillar Complex

ChemicalPest SpecificBacillus thuringiensis (Kurstaki; Btk, or Azaiwi; Bta)Many materials registered

e.g. Dipel, Thuricide, Biobit, Cutlass, etc.• Short persistence timing critical• Stomach poison coverage important• Weak on looperSpinosad (Entrust)

Broad SpectrumPyrethrin• Multiple applications• Resistance can be a problem• Eliminate biological controls


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Pest Specific Insecticides for Key Pests

Control caterpillar pests at thresholds when needed

Conserve beneficial organisms

Btk or spinosad

Crop Growth stage

Threshold

(% infestation)

Cabbage Seed bed 10%

Transplant-cupping 30%

Cupping-early head 20%

Mature head 10%

Broccoli/cauliflower Seed bed 10%

Transplant-first curd

50%

Curd present 10%Courtesy of R. Groves, 2013

http://www.entomology.wisc.edu/vegentoCourtesy of R. Groves, 2013

Managing Tomato Late Blight in Organic Systems in Wisconsin

Amanda GevensExtension Plant PathologistUniversity of Wisconsin-Madison

Courtesy of A. Gevens, 2013

Tomato Late Blight Symptoms(Phytophthora infestans)


Late blight disease cycles


Information Collection & Sharing

usablight.org


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usablight.org



usablight.org


National Late Blight OccurrencesDuring 2009-2012

2009201020112012

Data for 2011-12 from usablight.org, 2009-10 data from state extension reports

Confirmed reports on tomato andpotato


Hosts of Late Blight, 2009-2012

National data collected on 10 January 2012 from usablight.org

Wisconsin data


County Crop Date of Detection Clonal Lineage

Barron Potato/Tomato 31 July 2012 US-23

Adams Potato/Tomato 31 July 2012 US-23

Portage Potato/Tomato 2 August 2012 US-23

Oneida Potato 4 August 2012 US-23

Waushara Potato/Tomato 20 August 2012 US-23

Marathon Potato/Tomato 22 August 2012 US-23

Rusk Tomato 23 August 2012 US-23

Sheboygan Tomato 24 August 2012 US-23

Sauk Tomato 10 September 2012 US-23

Eau Claire Tomato 14 September 2012 US-23

Confirmed Late Blight in Wisconsin 2012

For confirmation and clonal lineage ID, we use:symptoms & microscopic presence of sporangia consistent with Pinf, Agdia Phytophthora Immunostrip tests, allozymes analysis at Gpi locus, and PCR with Pinf primers


Tomato late blight control

• Varietal resistance• Mountain Magic,

Plum Regal, Defiant• Bring only disease-free

material into high tunnel or field

• Preventative fungicides when disease is present in your region


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Defiant PhR (F1)

(Solanum lycopersicum) New! Bred for both disease resistance and taste.This mid-size slicer has high resistance to late blight and intermediate resistance to early blight combined with great taste. The 6-8 oz., globe-shaped fruit are smooth and medium-firm with good texture. Deep red internal and external color. High-yielding, medium-sized plants are widely adaptable. Defiant was traditionally bred to inherit the Ph-2 and Ph-3 major genes for late blight (Phytophthora) resistance. Our thanks to No. Carolina State Univ. for their cooperation. Determinate. Avg. 155,000 seeds/lb. Mini: 20 seeds. Days to Maturity or Bloom: 70

Mountain Magic F1

New! Excellent flavor and late blight resistant. (Ph-2 and 3)Mountain Magic produces high yields of 2 oz., bright red, round salad tomatoes with very sweet flavor. The uniform, crack-resistant fruits may be truss harvested. Great in salads or right off the vine. Indeterminate. Avg. 150,000 seeds/lb. Mini: 10 seeds.Days to Maturity or Bloom: 66

Plum Regal F1

New! A productive plum tomato with late blight resistance. (Ph-3)Medium-size plants with good leaf cover produce high yields of blocky, 4 oz. plum tomatoes. Fruits have a deep red color with good flavor. Good disease resistance package. Determinate. We are expecting seed to be available mid-February of 2011. Avg. 190,000 seeds/lb. Mini: 20 seeds.Days to Maturity or Bloom: 68Backordered until 12/17/10

Late Blight Resistance in Commercial Tomato


Trt # Fungicide

1Untreated control (inoculated)

2Untreated control (not inoculated)

3 Zonix

4 EF400 low rate

5 EF400 high rate

6 Phostrol

7Champ Formula 2 low rate

8Champ Formula 2 high rate

9 baking soda

10 Oxidate

11 Serenade Soil

12 Regalia

13Ridomil Gold SL (45% ai)

14 Revus

15 Bravo Ultrex

16 Mycostat low rate

17 Mycostat high rate

fungicide applied prior to inoculation (2 hours)

fungicide applied after inoculation (2 days)

Percent leaf infection

Fungicide, Rate/Acre active ingredient

1. Untreated control (inoculated)

NA

2. Untreated control (not inoculated)

NA

3. Zonix, 100 ppm diluted in water

rhamnolipidbiosurfactant

4. EF400, 64 fl oz/100 gal water

horticultural oil blend

5. EF400, 96 fl oz/100 gal water

horticultural oil blend

6. Phostrol, 10 pt phosphorous acids7. Champ Formula 2, 1.33 pt

copper hydroxide

8. Champ Formula 2, 2pt copper hydroxide

9. baking soda, 1 tbpn/gal water

sodium bicarbonate

10. Oxidate,1 gal Oxidate/100 gal water

hydrogen peroxide

11. Serenade Soil, 200 fl oz Bacillus subtilis

12. Regalia, 1 qtReynoutriasachalinensis

13. Ridomil Gold SL (45% ai), 1 qt

mefenoxam

14. Revus, 8 fl oz mandipropamid

15. Bravo Ultrex, 1.8 lb chlorothalonil

16. Mycostat, 8 fl oz oil extract

17. Mycostat, 16 fl oz oil extract

Screen on late blight susceptible ‘Brandywine Red’ tomato detached leaves, 5‐week‐old greenhouse‐grown plants. Phytophthora infestans US‐23 Isolate WI‐Pi‐16.

Comparison of organic fungicides for tomato late blight control


Strategizing powdery mildewmanagement in cucurbit crops

Amanda J. Gevens

Extension Plant PathologistUniversity of Wisconsin-Madison

Disease Introduction & Symptoms

• Since 1800’s, PM has been recognized worldwide as a major cucurbit disease in field and GH

• All cucurbits are susceptible, however, there are some with resistance (cucumber and melon)

• PM is problematic on squash, pumpkin, melon, and watermelon and impacts yield by decreasing the size, number, and quality of fruit, and shortening the length of time fruit can be harvested


The Cucurbit Powdery Mildew Pathogen

Can be caused by 2 different debris-borne fungi

Most commonly found & most vigorous:Podosphaera xanthii or P. xanthii

formerly Sphaerotheca fuliginea

Less common:Golovinomyces cichoracearum

formerly Erysiphe cichoracearum


W. Gartel

B. Kendrick

M. McGrath

Cucurbit Powdery Mildew Disease Cycle

ascospores fromcasmothecia

conidia

2 potential spore types


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Powdery Mildew Disease Cycle & Aerial Movement – P. xanthii

Without casmothecial stage, crop rotation has limited management effect on PM

Aerial movement of pathogenalso plays a role in PM


Vegetable Disease Timeline for WI

Early blight, Septoria blight

Damping-off,Poor emergence

Late blight , Downy mildew, Powdery mildew

Post-harvest rots

April-May June July August September October


• Earliest maturing leaves lower in the canopy are typically first to exhibit symptoms

• PM infection can predispose plants to other diseases

• Fruit infection is rare, however, fruit can be impacted by sunscald when foliage is lost

• On pumpkins, PM can infect stem and reduce quality of the ‘handle’, shortening storability due to increased risk for secondary infection

Powdery Mildew Symptoms

J. Brust, Univ. of MD B. Precheur, Ohio State Univ. Ext. Courtesy of A. Gevens, 2013

Powdery Mildew Symptom Development

• Talcum-like growth develops on plants when temperatures are cool (68-81°F), humidity is high, free water is low, and light intensity is low

• Wet leaves limit powdery mildew (unlike most other diseases)

W. Gartel


Management of Powdery Mildew Cultural Control

Select resistant cultivars•Good selections termed “PMR” meaning resistance from 1 parent or “PMRR” (resistance from 2 parents) in cucumber, melon, squash, pumpkin

•Currently available PMR cultivars are primarily resistant to PM races 1 and 2 (not completely race-defined).

•Other races (ie: S) are becoming more common in the eastern U.S. and there are few commercially available “S” PMR melon cultivars available (ie: ‘Diva’, ‘Passport, ‘Superstar’)

•It is likely that most WI PM is of race 2 based on 2009-2010 host differential tests - PMR cultivars of melon, pumpkin, squash should be effective against P. xanthii races 1 & 2

•In watermelon, resistance to race 1 is multi-genic and is independent from resistance to race 2


Management of Powdery Mildew Cultural Control

• Reduce plant density to reduce relative humidity

• Adjust planting dates plant early or harvest before pressure increases, long season cucurbits have higher risk

• Consider some overhead irrigation when conditions continue to favor dry foliage – for this disease, some water can act as a fungicide

• Destroy volunteer plants and control cucurbit weedsManaging field debris between production seasons can help limit debris-borne sources of inoculum


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Autograph Burpless26

Calypso Carolina Cobra Tasty Jade

Competitor Dasher II Daytona Diamonte Diva Thunder

Eureka (F1) Fanfare General Lee

Genuine (F1) Greensleeves Thunderbird

Impact Indio Indy Intimidator Jackson Classic Turbo

LafayetteClassic

Lynx Market-more 76,

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Olympian (F1) Panther Tyria (F1)

Prancer Slice More (F1)

Socrates (F1)

Speedway SR2389CW Ultra Pak

Stonewall SuvoLong

Sweet Slice

Tasty Bright Tasty Green

Slicing cucumber

Cucurbit cultivars with PM resistance

Compiled by:Meg McGrath, Cornell UniversityL.I. Hort. Research Lab., NYCourtesy of A. Gevens, 2013

Alibi Amour Calypso Classy Cross Country Eclipse

Eureka FancipakM

Feisty FM5020 Jackson Classic Jackson Supreme

Lafayette H-19 LittleLeaf

Moxie Napolean Patton Pioneer

Salty Sassy SMR58 Spear It Spunky Timor

Vlasstar Wellington Wisconsin

Zapata

Pickling cucumber


Aladdin Magician Magic Lantern

Bumpkin Pure Gold Hobbit

Gold Dust Harvest Princess Merlin

Gladiator Super Herc Iron Man

Gold Boullion Harvest Time Golden Condor

One Too Many Scarecrow Touch of Autumn

Pumpkin

Meg McGrath, Cornell UniversityL.I. Hort. Research Lab., NY


Ambrosia Bush Star Harper Hybrid Saticoy

Aphrodite Classic Minerva Sugar Bowl

Asian Crescent Moon Odyssey Sweet N Early

Athena Earligold Primo

BurpeeHybrid

Eclipse Pulsar

Muskmelon


Arava Edonis Minnesota Midget

Bolero Gallicum Rayyan

Cream de Menthe Golden Beauty Savor

Crete Honey Brew Sweetie #6 (Butterscotch)

Dorado Marygold

Melon Specialty



General Patton Patriot II Sunglo Sunray

Summer Squash - Yellow


Payroll Sebring

Summer Squash - Zucchini

Autumn Delight Royal Ace Table Star Taybelle PM

Winter Squash - Acorn

Bugle RBX 3106

Winter Squash – Butternut

Bush Delicata Celebration Cornell’s Bush Delicata Harlequin

Metro PMR Sweet Lightning TipTop PMR

Winter Squash – Specialty Squash



In most years, low levels of PM can be tolerated and not impact yield and quality

However, when conditions are favorable, ie: disease pressure is great prior to or at fruit set, a susceptible variety is grown, fungicides may be needed to manage disease

In pumpkins – good PMcontrol means better ‘handle’quality for improved appearance and storability

Management of Powdery Mildew Chemical Control (organic)


Management of Powdery Mildew Organic Chemical Control

Biorationals/Biologicals

Oils (Trilogy, Sporan, JMS Stylet Oil)

Silicon (soil amendment, when needed, enhances plant defense)

Phosphorous acids (Phostrol, not OMRI listed)

Peroxigens (Oxidate is hydrogen dioxide – stable form)

Potassium bicarbonate salts (Armicarb, Kaligreen, )

Ampelomyces (AQ10 Ecogen, fungus attacks P. xanthii pathogen, biological control)

Cow’s milk (10% solution, don’t exceed 30%)

Bicarbonates (0.5%, don’t exceed 2% solution baking soda, enhanced with soap, surfactant or oil addition)

Bacillus spp. (Sonata, Serenade, Rhapsody)

Water Lactic acid (Antica) Reynoutria sachalinensis (Regalia, induces host resistance, OMRI listed)


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Comparing efficacy of biorational & organic fungicides for control


Comparing efficacy of fungicides for cucurbit powdery mildew control

Meg McGrath, Cornell Univ.L.I. Hort. Research Lab., NY


Once a fungicide application is made, continue on a 7 or 14-day spray program (depending upon the susceptibility of variety, disease pressure and fungicide)

Effective Fungicides for PowderyMildew Control - Summary


Downy vs. Powdery MildewBoth cucurbit diseases are termed “mildews” but they are different pathogens with different environmental requirements that result in different symptoms


Downy mildew Powdery mildew

Wet, cloudy conditions Somewhat dry conditions

Variable time of appearance Typically late season appearance

In WI, so far, most impact on cucumber

In WI, most impact on pumpkin and squash

Brown‐purple fuzzy spores on leaf undersides, no sporulation seen on stems or petioles

White talcum spores on both sides of leaves, on stems & petioles

No fruit infections Typically, no fruit infections

A ‘water mold’ A true fungus

Generally, the fungicides that are most effective for controlling powdery mildew are not the best for controlling downy mildew.

Comparing “the mildews”


Where was downy mildew in 2012 and is it gone for good?

No reports in WI; late season report in MN; few reports in IN, IL; many reports in MI, OH

Drought conditions limited downy mildew

In recent years, WI has had mid- and late-season downy mildew on primarily cucumber

There is risk of downy mildew to WI cucurbits in 2013 – resulting incidence/severity is dependent upon temperature and moisture


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G. Holmes

Downy Mildew Symptoms on Cucumber


Cucurbit Downy Mildew Forecasting

Site offers various resources including pathogen and disease information, management guidance, forecasts, and serves as a link for collaborators of the national program

http://cdm.ipmpipe.org/

Cucurbit

Early Blight and Septoria Leaf Spot of Tomato

Early Blight

• Foliar disease

• First affects older leaves

• Irregularly shaped brown spots with concentric rings (usually turns yellow on perimeter)

• Infected green fruit have dark, leathery, sunken spots near stem end

Septoria Leaf Spot

• Small, circular spots on upper surface of lower leaves

• Smaller and more numerous than early blight

• Tan or light-colored center

Potential Impact• Loss of leaves• Sunscald of exposed fruit• Fruit lesions due to EB• Poor fruit quality (lower sugar content)• Plants produce less fruit• Severity increases over years

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Management• Plant tomatoes where no tomatoes, potatoes,

peppers, or eggplants have been for the past 3-4 years

• Consider moving tomatoes to pots for a year or two if tomato leaf blights occur regularly in the garden

• Keep tomato leaves as dry as possible• Stake or cage plants• Pinch off lower leaves with leaf spots. Never

remove more than 1/3 of the plants leaves• At the end of the season, remove or bury

infected tomato plants to reduce the amount of fungi that survive to the following season

Early Blight and Septoria Leaf Spot

• Can come from contaminated transplants or seeds

• Survives in leaf debris from year to year

• Rain and irrigation splash fungal spores up onto new leaves from the soil and plant debris below

Management

• Wide row and plant spacing

• Stake or trellis (disinfect each season)

• Drip irrigation• Mulches• Keep foliage dry

Early Blight Resistant Varieties

Mountain series from NC:• Mountain Pride,

Supreme, Gold, Fresh and Belle

• Late maturing and fruit small

organic vegetable production outline level 2 master ...€¦ · 6 squash bug, anasa tristis...

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