Pepper disease controlPepper disease control

ParmParm RandhawaRandhawa, Ph.D., Ph.D.California Seed & Plant LabCalifornia Seed & Plant Lab

Agenda

Symptom recognition

Where the disease come from

Disease Management

Check list

Disease control in greenhouse Depends on

Growing in soilContainers (with potting mix)Hydroponic (Rockwool etc)

Fusarium stem rot

Fusarium - Infection at nodes

Red perithecia(Sexual spores can discharge to 6 ft at night

FusariumHow is pathogen introduced

Soil (people, tools)Previous crop (debris etc)Airborne ascospores

Fusarium - Control

Avoid salt burn (if rockwool dries)Reduce humidity (slow temp increase at night)Bio-control

Erwinia stem canker

Fusarium like symptoms Water soaking

Erwinia carotovoraHow pathogen get introduced

Irrigation with untreated water (ponds, rivers)

Handling from people (hands)

Erwinia - Control

Treat water (1 ppm Chlorine kills in 30 seconds)

Workers (wash hands)

Xanthomonas

Xanthomonascontrol

Buy tested seedResistant varieties (multiple races)Actiguard (induces resistance)Copper / Maneb sprays

Bacterio-phage application can help

Anthracnose (fruit rot)

Anthracnose control

Seed treatmentDebris removal

Damping off - nursery problem

Damping off - control

Disease free media (steamed)Sanitation (trays etc)Raised benchesDo not over waterTreated water

2-Fungicide drench can help

(Ridomil + Topsin M)

Sudden WiltPhytophthora capsici

Phytophthora: All parts nfected

PhytophthoraWhere it comes from

Seed borne ? Wind blown rains bring spores from other plants (tomato, cucurbits, weeds)Irrigation water (rivers)Soil movement (oospores survive)Fungus gnats

Disease develops in 3-4 days after infection

PhytophthoraManagement

Treat waterDisinfection of nursery containersFungicidesGood drainage (drainage area – Keep weed free)

Lab ID should be done to

select correct fungicide

Control with Revus + Rodomil

Sclerotinia white mold

White mold on stem

Black sclerotia inside stem

Germinating sclerotia

Sclertotinia controlCool moist weather disease

Air circulationSanitationTopsin M

Southern blight - managementHot weather disease

SanitationAerationSpot application of fungicides (Quadrisetc)

Other fungal / bacterial diseases

BacteriaRalstonia, Pseudomonas syringae

Fungi– Pow mildew, Verticillium, Cercospora,

Stemphyllum, Downy mildew, gray leaf spot

I have assumed that these are less

frequent in greenhouse pepper culture

VirusesCause malformation but do not killMany viruses – same symptom One virus – many symptoms

Symptoms provide a clue but Lab test is needed for Identification

How viruses get introduced

Beet curly topLeaf hopper

Tobacco mosaic, tomato mosaic, pepper mild mottle

Seed

Chino del tomate, Pepper mild tigre, Pepper hausteco, Sinaloa leaf curl

White fly

Tomato spotted wiltThrips

Cucumber mosaic, Potato virus Y, Tobacco Etch, Alfalfa mosaic, Pepper mottle

Aphids

15-Virus PCR test

TSWV, TMV, ToMV, CMV, PMMV, TEV, PVY, AMV, PMV

RNA

Gemini group (CdTV, PHV, SLCV, TPV, SGMV), BCTV

DNA

VirusesTest

Aphid transmitted viruses

CMV

Chilli Veinalmottle

Tobacco etch

Potato virus Y

Alalfa mosaic virus

Bleaching of leaves

Thrips transmitted viruses

Tomato spotted wilt

White fly transmitted

Gemini viruses (DNA viruses)

Chino del tomate virus (CdDT)

Serrano Golden Mosaic

Texas pepper virus

Leaf hopper transmitted

Beet curly top

Seed transmitted

viruses

Tobacco mosaic

Tomato mosaic

Pepper mild mottle virus

Virus control

Screens for insect controlHand wash for tobamo virusesTested seed (for tobamo viruses)No smoking (for TMV)Weed removalStylet oil sprays for aphid borneInsecticides

Physiology disorders

Color spots

(varietal)

Cracking(water imbalance)

Blossom end rot(calcium)

Disease management

Disease

Virulent Pathogen

Susceptible Host

Favorable Environment

Pathogen eliminationWeed removalInsect screensPlastic cover on soilIrrigation water treatmentFoot bathEtc

Double door for insect control

Serves as air-lock

Clean cement walkway will keep

Crawling insects away (ants)

Boot scrubber to reduce soil going into greenhouse

Foot bath to sterilize boots Greenshield, Physan20

Hand wash station (near entry)(Disease control during pruning, tying,

harvesting etc)

Weed cloth – 10 feet around greenhouse

Reflective mulch around greenhouse

(to confuse insects)

Check for any holes in the screen

Debris removal at end of crop

Before After

Plastic mulch on ground will keep soil pathogen away

Another Plastic Surface

Cull Pile

Away from greenhouseMake holeCover with soil later on

Special care of nursery

1 foot off ground

Crop Free Period

Solarization (130F)

Elimination of susceptible host

Resistant varietiesare available

TMV, PMMV, Xanth,Phytophthora

Creating unfavorable environment

Heaters for step heating at nightFans to reduce free moistureFertilizer program for inducing resistanceScouting and treatment to reduce insect /disease pressureBiologicals to slow down disease

Discontinuous system is good

Aeration and thus disease

control is same in this “V” trellis

Keeping pedicel controls post-harvest Erwinia soft rot

Biologicals keep working against pests

Rhapsody, Serenade, Sonata

GSB, PM, DM

Rootshield, Pre-stop, Mycostop

Root fungi

Gliocladium (Pre-stop) is parasitic on Rhizoctonia

Trichoderma for disease control

(harzianum, viride, hamatum species)

Scouting for insects / diseases

Lab selectionChoose a lab that gives quick diagnosis

You can send sample to me

Pack goodInclude shipping documents (permit)Use Red /white shipping label (from me)Ship

Ready to ship

Packing

Making action plan

Assessment of riskCheck list

Risk inventory

Weeds Other cropsProximity of cull pileHistory of previous crop

Weed risk

End of Season: Check List

Met with staff and reviewedScouting supplies are ready

Weeds, debris removed

Tools, carts etc disinfected

Foot bath ready

Nursery is treated for fungus gnats

Irrigation lines flushed and disinfected

Trash hole is ready

Thank you