Botrytis Management in Cut Roses Melissa Muoz, James E. Faust & - - PowerPoint PPT Presentation

Botrytis Management in Cut Roses

Melissa Muñoz, James E. Faust & Guido Schnabel

Ph.D. Horticulture

• Floriculture Physiology
• Effects of environmental and cultural factors on

the production of ornamental greenhouse crops

• Botrytis found on pansy flowers at a Florida

nursery that was resistant to all of the main fungicides used to control Botrytis

Ph.D. Plant pathology

• Integrated management of diseases
• Botrytis control in strawberries and blackberries
• Fungicide resistance mechanisms
• Decision-support models and smart-phone apps

to reduce and better time pesticide applications

Context

BBC news

• Botrytis cinerea:

üUbiquitous ü200 species plant hosts üNecrotrophic

• Roses:

üReduction in the postharvest quality, leading to substantial economic loss by growers and wholesalers

The problem

The problem

400x 400x

Ø Leaf wetness Ø 93% Relative humidity Ø 15-25ºC Optimum. 0ºC to 35.5ºC

Dis Diseas ase t trian iangle le

Susceptible host Virulent pathogen Conducive environment

To evaluate weather conditions in commercial greenhouses and their relationship with Botrytis occurrence

Co Context

• SAS - Strawberry Advisory System: is a web site, and smarth-phone

app that provides an easy way for strawberry growers in Florida to track and forecast risk levels for Botrytis and anthracnose fruit rot

• diseases. It also provides fungicide application recommendations and

allows growers to receive alerts for selected weather stations via push notifications.

Installation of weather stations

• Solar radiation (W/m2)
• Leaf wetness (min)
• Air temperature (°C)
• Relative humidity (%)
• Dew point (°C)
• Leaf temperature (°C)
• Soil temperature (°C)
• Electrical conductivity (mS/cm)
• Water content of soil media (%)
• Wind speed (m/s)
• Wind direction

Typical daily weather pattern

100 200 300 400 500 10.0 12.5 15.0 17.5 20.0 22.5 50 60 70 80 90 10 20 30 40 50 60

6 : 7 : 8 : 9 : 1 : 1 1 : 1 2 : 1 3 : 1 4 : 1 5 : 1 6 : 1 7 : 1 8 : 1 9 : 2 : 2 1 : 2 2 : 2 3 : : 1 : 2 : 3 : 4 : 5 :

Hour

Solar radiation (W/m2) Air temperature (oC) Relative humidity (%) Leaf wetness (min/h)

BOTRYTIS RISK MODEL DEVELOPMENT

Botrytis infection risk Month Da Date Le Leaf af wetn tness (h (h) Te Temperature (oC) C) In Infect ection risk (%) %) Ri Risk February 2/20/17 7.5 11.4 6.3 No February 2/21/17 0.0 16.9 1.4 No March 3/17/17 12.5 11.6 16.9 No April 4/15/17 12.5 11.3 15.9 No April 4/17/17 24.0 14.3 88.1 High May 5/29/17 11.5 11.6 14.2 No May 5/30/17 10.6 11.9 12.5 No Jun 6/9/17 19 14.3 67.7 Mid Jun 6/14/17 15.3 13.2 36.9 Low Jun 6/15/17 8.0 12.8 8.5 No Jun 6/16/17 24.0 15.4 91.5 High Jun 6/29/17 13.5 11.1 17.9 no Jun 6/30/17 17.8 13.2 51.8 Mid July 7/1/17 20.1 15.0 76.6 High July 7/15/17 14.5 11.7 24.5 No July 7/28/17 15.25 11.9 29 No August 8/17/17 14.5 11.7 24.9 No September 9/02/17 14.8 11.7 25.6 No September 9/03/17 24 12.2 76 High

Pr Predicte ted vs. real eal Botr trytis tis inc incidenc idence e values alues

10 20 30 40 50 60 70 80 90 100 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 Incidence (%) Week Actual Botrytis Incidence Predicted Botrytis Incidence

• The disease risk model has value and can

become as part of an integrate management program of Botrytis

• Weather stations are a tool that may

improve timing for fungicide applications

To evaluate Botrytis spores density in commercial greenhouses and their relation to cultural practices

Installation of spore traps

Counting spores process

100 x 400 x

Spores density

Spores density

Spores density

Cultural practices

• Harvesting
• Pinching
• Sweeping floors*
• Blowing (debris

removal)*

• Manual debris

removal

• Downy mildew

removal

• Botrytis removal
• Dead stems pruning
• Dead stems removal
• Weeding
• Drenching
• Fungicide spray

application

• Pesticide spray

application

• Thermo-fogging
• Supplementary

watering of beds

• PGRs application
• Cutting zone cleaning
• Plastic change
• Fertilizer containers

change

The number and type of cultural practices have an effect on Botrytis spore density

To determine Botrytis severity in different rose tissues from commercial shipments

• South American Study:
• One Farm
• 2 Greenhouses
• One Susceptible Variety: Orange Crush
• Six Shipments
• Geographical Study:
• Four Locations: Ecuador, Africa, Colombia;

Guatemala or Mexico

• Four Shipments

Assessi ssessing g Botrytis s Occu ccurren ence ce & Se Sever erity y on Commer mmerci cial Rose se Sh Shipmen ments

Inner Petals Outer Petals Mid Petals Sepals Ovary and Stamens Leaves Stems

Sa Samp mple Co Collection and Processing

Petals

Results: Botrytis occurrence in different plant tissue:

South America Study

Petals are the most susceptible tissue Stems Sepals Stamens &

• vary

73.7% 13.2% 7.9% 5.3%

Results: Botrytis occurrence in different plant tissue:

South America Study

Stems Sepals Stamens &

• vary

Outer 34.2% 13.2% 7.9% 5.3%

Petals

A significant portion of the infection occurs in tissues that are not exposed (Mid and inner petals, stamens and ovary)

Mid 26.3% Inner 13.2%

To assess fungicide resistance profiles in Botrytis isolates from commercial cut roses

Context

• Resistencia: refers to an acquired, heritable reduction in sensitivity of

a fungus to a specific anti-fungal agent (or fungicide).

• FRAC (Fungicide resistance action committee): Group together the

fungicides that are in risk of cross resistance development, because have a similar mode of action

Inner Petals Outer Petals Mid Petals Sepals Ovary and Stamens Leaves Stems

Control FRAC 9: Cyprodinil FRAC 12: Fludioxonil FRAC 17: Fenhexamid FRAC 2: Iprodione FRAC 1: Thiophanate-methyl FRAC 19: Polyoxin D FRAC 7: Boscalid FRAC 7: Fluopyram FRAC 7: Penthiopyrad FRAC 7: Isofetamid FRAC 7: Pidiflumetophen

FUNGICIDE RESISTANCE PROFILES: 11 FUNGICIDES THAT BELONG TO 7 CHEMICAL CLASSES (FRAC)

Fung Fungic icide ide Res esis istanc ance e Profiles iles

South America Study 49 Single spore isolates Geographical Study 58 Single spore isolates

Fung Fungic icide ide Res esis istan ant t Is Isola lates es: 6 Shipm hipmen ents ts

(S (South Amer meric ica a Study)

20 40 60 80 100 FRAC 1 FRAC 2 FRAC 9 FRAC 7 FRAC 17 FRAC 7 FRAC 7 FRAC 7 FRAC 12 FRAC 7 FRAC 19 Resistant Isolates (%)

Shipment 2 n=11

0.0 20.0 40.0 60.0 80.0 100.0 FRAC 1 FRAC 2 FRAC 9 FRAC 7 FRAC 17 FRAC 7 FRAC 7 FRAC 7 FRAC 12 FRAC 7 FRAC 19 Resistant Isolates (%)

Shipment 3 n=5

0.0 20.0 40.0 60.0 80.0 100.0 FRAC 1 FRAC 2 FRAC 9 FRAC 7 FRAC 17 FRAC 7 FRAC 7 FRAC 7 FRAC 12 FRAC 7 FRAC 19 Resistant Isolates (%)

Shipment 5 n=7

0.0 20.0 40.0 60.0 80.0 100.0 FRAC 1 FRAC 2 FRAC 9 FRAC 7 FRAC 17 FRAC 7 FRAC 7 FRAC 7 FRAC 12 FRAC 7 FRAC 19 Resistant Isolates (%)

Shipment 6 n=9

Resistant Isolate Sensitive Isolate

20 40 60 80 100 FRAC 1 FRAC 2 FRAC 9 FRAC 7 FRAC 17 FRAC 7 FRAC 7 FRAC 7 FRAC 12 FRAC 7 FRAC 19 Resistant Isolates (%)

Shipment 1 n=4

20 40 60 80 100 FRAC 1 FRAC 2 FRAC 9 FRAC 7 FRAC 17 FRAC 7 FRAC 7 FRAC 7 FRAC 12 FRAC 7 FRAC 19 Resistant Isoates (%)

Shipment 4 n=13

Resistant Isolate Sensitive Isolate

Fung Fungic icide ide Res esis istan ant t Is Isola lates es

(So South America St Study) y)

10 20 30 40 50 60 70 80 90 100

Resistant Isolates (%)

Fungicides applied in the last year

Fluxapyroxad : FRAC 7 Pyrimethanil: FRAC 9 Famoxadone: FRAC 11 Azoxystrobin: FRAC 11 Propamocarb: FRAC 28 Fluopicolide: FRAC 43 Cymoxanil: FRAC 27 Tebuconazole: FRAC 3 Fluazinam: FRAC 29 Prochloraz: Multisite Captan: Multisite Iminoctadine: Multisite Zinc diethyldithiocarbamate: Protectant

Fung Fungic icide ide Res esis istan ant t Is Isola lates es

(G (Geogr

• graphical S

Study) y)

Aislamientos resistentes Aislamientos sensibles

10 20 30 40 50 60 70 80 90 100 FRAC 1 FRAC 9 FRAC 2 FRAC 17 FRAC 7 FRAC 7 FRAC 7: FRAC 12 FRAC 7 FRAC 7 FRAC 19

Resistant isolates (%)

Ecuador n=23

10 20 30 40 50 60 70 80 90 100 FRAC 1 FRAC 9 FRAC 2 FRAC 17 FRAC 7 FRAC 7 FRAC 7: FRAC 12 FRAC 7 FRAC 7 FRAC 19

Resistant isolates (%)

Guatemala n=4

10 20 30 40 50 60 70 80 90 100 FRAC 1 FRAC 9 FRAC 2 FRAC 17 FRAC 7 FRAC 7 FRAC 7: FRAC 12 FRAC 7 FRAC 7 FRAC 19

Resistant isolates (%)

Africa n=26

10 20 30 40 50 60 70 80 90 100 FRAC 1 FRAC 9 FRAC 2 FRAC 17 FRAC 7 FRAC 7 FRAC 7: FRAC 12 FRAC 7 FRAC 7 FRAC 19

Resistant isolates (%)

Colombia n=4

10 20 30 40 50 60 70 80 90 100

FRAC 1 FRAC 9 FRAC 2 FRAC 17 FRAC 7 FRAC 7 FRAC 7: FRAC 12 FRAC 7 FRAC 7 FRAC 19

Resistant isolates(%)

Mexico n=2

Resistance:

• In some chemical classes, the resistance effect is

conserved even when the fungicides are not used in the present but they were used before e.g. FRAC 1

• Resistance to some fungicides can be decreased or

disappear if the resistance has an effect on the fitness of the pathogen and no applications of the fungicide are done in a while e.g. FRAC 7- Boscalid on strawberries

Botrytis symptoms

Abiotic symptoms

Pink spots on petals are not Botrytis symptoms

Alternaria sp. Aspergillus sp. Diplodia sp.

400x 400x 400x

Biotic Symptoms

12 h 8 h

Spore suspension Water

ASSESS THE INITIAL SYMPTOMS FOR BOTRYTIS

4 h

Incubate (high RH)

DAY 1 DAY 2 DAY 3 DAY 4 DAY 5 DAY 6 DAY 7 4h 8h 12h

Incubation duration

Symptom Development

Incubate (high RH) DAY 9

Latent Infections

After 4 h of incubation (spores present on wet petals), roses display no

• symptoms. However, latent infection has occurred and sporulation will
• ccur if the flowers are exposed to the proper conditions (high humidity).

After >8 h of incubation, Botrytis symptoms appear on petals (beige/tan/discolored spots).

Comprehensive approach

Susceptible host Virulent pathogen Conducive environment

Ca and Si content in rose tissue

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Ca (%) Rose tissue

Calcium content in different rose tissue

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 Si (%) Rose tissue

Si content in different rose tissue

Acknowledgements

Sch Schnabel La Lab: Mengjun Hu Madeline Dowling Martha Froelich Karen Bryson Linus Smith Brodie Cox Fa Faust Lab: Katie Bennett Kelly Lewis Jiwoo Park

QUESTIONS?

Questions? ¡Muchas gracias!