Fundamentals of Caneberry Production Workshop Understanding Pathogen Biology & Diversity ESTABLISHMENT CONSIDERATIONS OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Establishment Considerations Crown gall, nematodes, and viruses are best controlled through prevention or elimination prior to planting  Crown gall is caused by soil-borne bacteria which result in tumorous growth on plant crowns and root systems  Nematodes directly destroy roots and increase crown gall and root rot; dagger nematodes spread caneberry viruses  Viruses reduce vigor, yield, fruit quality; cause plant death

Martin et al. 2013 Martin et al. 2013 Martin et al. 2013 Martin et al. 2013 Many viral diseases affect caneberries including Blackberry Yellow Vein Disease (above) Understanding Pathogen Biology & Diversity ESTABLISHMENT CONSIDERATIONS OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Viruses and Crown Gall • Since viruses and crown gall can be introduced through propagation, clean planting stock is essential. • Tissue-cultured plants are more likely free of pathogens

• Wounds are required for crown gall infection. Every effort should be made to avoid wounding roots and lower stems.

• Once infected, plants cannot be cured of viruses. 1. Set out only disease-free plants. 2. Remove wild blackberries growing nearby that can harbor caneberry viruses 3. Rapidly remove symptomatic plants Understanding Pathogen Biology & Diversity ESTABLISHMENT CONSIDERATIONS OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Nematodes • Nematode control, especially of dagger nematode, is essential to prevent virus spread; even low levels of dagger nematodes are dangerous.

• Prior to land prep, all potential sites should be sampled for root-knot, root-lesion, dagger and other nematodes.

• Fumigation prior to planting is often recommended to reduce/prevent nematode issues. • Chemical controls include: Pic-Clor 60, Paladin, Vapam, Sectagon 42, K-PAM HL, and Telone II. Understanding Pathogen Biology & Diversity PHYTOPHTHORA ROOT ROT OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Phytophthora Root Rot

• Reportedly caused by several Phytophthora spp. • Phytophthora spp. produce zoospores & spread via water • Disease often first seen in poorly drained areas of the field • Damage to roots leads to primocane collapse shortly after emergence in the spring as well as wilting and chlorosis of floricanes

W. Wilcox https://ohioline.osu.edu/factsheet/plpath-fru-14 https://ohioline.osu.edu/factsheet/plpath-fru-14 Reddish brown root discoloration Cane collapse due to root rot Root rot affected plant (left) Understanding Pathogen Biology & Diversity PHYTOPHTHORA ROOT ROT OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Management

• Cultural controls are critical since root rot is generally a problem of low, poorly-drained, excessively moist sites.  Ensure adequate drainage prior to planting via site selection and/or proper bedding  Avoid excessive irrigation • Chemical controls for include phosphonates (ProPhyt, K- Phite, etc.) and mefanoxam (Ridomil Gold). • Note that chemical control is not effective for reversing root rot damage on plants with severe symptoms SOUTHEASTERN CANEBERRY SEASONAL SPRAY SCHEDULE

https://berrydealer.com/blackberries/ Example Seasonal Spray Schedule

Delayed Shoots Bloom Petal Cover Preharvest Harvest After Dormant 6” long Fall Sprays harvest Anthracnose & Spur Blight Cane Blight Leaf Spots Rusts & Powdery Mildew Botrytis & Rosette Orange Cane Blotch Understanding Pathogen Biology & Diversity ANTHRACNOSE OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Anthracnose • Caused by the fungus Elisnoë necator • Disease is more serious on raspberry than blackberry • Reddish-purple spots appear on primocanes in the spring • Spots develop into sunken lesions as the disease progresses • Infection of leaves (purple spots) and fruit (small, mis- shapen) can also occur

MyIPM App MyIPM App MyIPM App Early spots symptoms on primocanes Sunken lesions Understanding Pathogen Biology & Diversity ANTHRACNOSE OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Management

• Cultural controls include: • Removal of old floricanes immediately after harvest • Promoting rapid drying of the canopy through the use of weed free strips, black plastic, and drip-tape irrigation • Avoiding overhead irrigation to prevent splash dispersal • Avoiding excessive nitrogen applications

• Chemical controls include: • Application of lime sulfur in the late dormant period • In-season applications of additional fungicides (Abound, Quilt Xcel, Pristine, Cabrio, and Captan) Understanding Pathogen Biology & Diversity SPUR BLIGHT OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Spur Blight • Caused by the fungus Xenodidymella applanata (AKA Didymella applanata) • Generally more severe on raspberries than blackberries • Not widespread in southeastern US caneberries • Infections produce V-shaped lesions primocane leaves • Infections eventually spread from leaf margins, down the petioles, and then into the node

Bugwood.org T. McCamant Mary Ann Hansen V-shaped lesions w/yellow margins Purple/dark brown lesions on primocanes Understanding Pathogen Biology & Diversity SPUR BLIGHT OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Management

• Cultural controls include: • Removal of old floricanes immediately after harvest • Promoting rapid drying of the canopy through the use of weed free strips, black plastic, and drip-tape irrigation

• Chemical controls include: • Application of lime sulfur prior to spring growth • In-season applications of additional fungicides (Abound, Quilt Xcel, Pristine, Cabrio, and Captan) Understanding Pathogen Biology & Diversity CANE BLIGHT OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Cane Blight • Caused by the fungus Leptosphaeria coniothyrium • Fungal spores (conidia) are spread by rainsplash and infect canes through wounds. • Lesions appear on primocanes in summer, fall, and winter. • Cane death results when lesions girdle the vascular tissue.

MyIPM App MyIPM App MyIPM App Blighted canes often appear to be grey/silver Fungal pycnidia on cane surface Understanding Pathogen Biology & Diversity CANE BLIGHT OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Management • Cultural control recommendations include: • Avoid wounding of primocanes whenever possible • Pinch-off/tip primocanes once at desired height (3-4 ft) • Remove infected canes and old floricanes after harvest • Promote quick drying of the canopy via weed free strip • Avoid nutrition and water stress to plants

• Chemical controls recommendations include: • Apply fungicides such as Rally or Pristine after each day of pruning to protect wound site from fungal entry • Whenever possible, avoid pruning prior to rainfall events Understanding Pathogen Biology & Diversity BOTRYTIS FRUIT ROT AND BLOSSOM BLIGHT OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Botrytis Fruit Rot and Blossom Blight

• Caused by the fungus Botrytis cinerea • Fungal spores (conidia) readily infect blossoms & ripe fruit • Since conidia are dispersed by wind & rainsplash, persistent rain during bloom can result in significant infections • Can cause devastating preharvest and postharvest fruit rot

Oregon St. University NC State University MyIPM App Postharvest fruit rot Botrytis on ripening fruit Conidiophore and conidia Understanding Pathogen Biology & Diversity BOTRYTIS FRUIT ROT AND BLOSSOM BLIGHT OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Management • Cultural controls include: • Practices that create an open canopy to improve air circulation and speed drying of plant surfaces

• Chemical controls include: • Fungicide applications at early bloom, full bloom, and pre-harvest to protect flowers and ripening fruit (post bloom and pre-harvest sprays generally not required unless weather is cool and wet). • Fungicides include Rovral, Nevado, Iprodione, Elevate, Switch, Pristine, Luna Tranquility, Ph-D and Captan. • *Fungicide resistance is common with botrytis*

Understanding Pathogen Biology & Diversity ROSETTE (DOUBLE BLOSSOM) OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Rosette (Double Blossom) • Caused by the fungus Cercosporella rubi • More colorful, distorted petals produced (double blossoms) • Leafy shoots are produced from infected vegetative buds • Infected flowers on floricanes produce conidia which can infect primocanes in the late spring/summer • Primocanes don’t show symptoms until the next spring.

MyIPM App MyIPM App Phil Brannen Distorted petals (Double blossoms) Leafy shoots (witches’-broom) Fungal spores (conidia) Understanding Pathogen Biology & Diversity ROSETTE (DOUBLE BLOSSOM) OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Management

• Cultural controls include: • Removal of infected rosettes before they open to prevent fungal dispersal • Planting disease-free nursery stock away from wild blackberries • Removal of old floricanes immediately after harvest

• Chemical controls include: • Applications of fungicides including Switch, Abound, Pristine, and Quilt Xcel from first bloom until harvest. RUST DISEASES ON BLACKBERRY

https://berrydealer.com/blackberries/ Rust Diseases on Blackberry

• Two major rust diseases of blackberry • Orange Rust • Cane and Leaf Rust

• Appear superficially similar, but require different management

practices due to fungal MyIPM App MyIPM App Orange Rust biology Cane and Leaf Rust Understanding Pathogen Biology & Diversity ORANGE RUST OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Orange Rust • Caused by Arthuriomyces peckianus and Gymnoconia nitens • These fungi infect systemically and cause dramatic reductions in vegetative growth and fruit production • Shoots appear spindly and unfolding leaves initially appear stunted, distorted, and pale green in color • Infected floricanes produce no blossoms

http://teamrubus.blogspot.com/2013/04/anothe MyIPM App http://www.raspberryblackberry.com/is-it-blackberry-leaf-rust-or-orange-rust/ r-orange-problemorange-rust.html Distorted leaf margins Bright orange blisterlike aecia Spindly shoots Understanding Pathogen Biology & Diversity ORANGE RUST OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Management • Cultural controls are critical for managing orange rust At initial establishment: 1. Ensure plants are free of orange rust 2. Eradicate wild blackberries within 0.25 mi of planting On established plantings: 1. Thoroughly inspect when new canes are 12-18” 2. Promptly remove and destroy infected plants

• Chemical controls are not effective once plants are systemically infected • Strobilurin and DMI type fungicides are recommended to help reduce the number of new infections

Understanding Pathogen Biology & Diversity CANE AND LEAF RUST OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Cane and Leaf Rust

• Caused by fungus Kuehneola uredinis • This fungus does not infect systemically like the Orange Rust fungi Severe infection can cause premature MyIPM App • defoliation and increase winter injury • Results in significant economic losses in blackberry production • This fungus produces pustules on

MyIPM App both canes and leaves Understanding Pathogen Biology & Diversity CANE AND LEAF RUST OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Management • Cultural controls include the immediate removal of floricanes after harvest to limit primocane infection • Chemical controls can provide satisfactory control • Strobilurin and DMI type fungicides are recommended • Apply at green tip and prior to bloom, then resume after harvest until floricanes are removed. After floricane removal, delay sprays until scouting indicates new infections of primocanes. Understanding Pathogen Biology & Diversity RUST DISEASES SIDE-BY-SIDE OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Cane and Leaf Rust Orange Rust Significant blackberry disease Significant blackberry disease Nonsystemic fungal disease Systemic fungal disease Lemon yellow pustules on Bright orange pustules on both canes and leaves leaves only Leaf pustules don’t distort Leaf pustules distort leaf leaf margins margins Floricane removal after Complete destruction of harvest is recommended infected plant is necessary Sanitation and fungicide Fungicides will reduce new sprays can provide infections, but infected plants satisfactory control must be destroyed Understanding Pathogen Biology & Diversity ORANGE CANE BLOTCH OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Orange Cane Blotch • Caused by the parasitic alga species Cephaleuros virescens • Algal sporangiophores form an orange felt-like material on blackberry stems; release zoospores under wet conditions. • Blotches on primocanes first appear in the late summer/fall • Blotches crack canes and may provide entry for pathogens. • Orange blotches formed on canes can be mistaken for rust.

MyIPM App MyIPM App MyIPM App Blotches on canes Cracking blotches Sporangiophores within blotch Understanding Pathogen Biology & Diversity ORANGE CANE BLOTCH OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Management

• Cultural controls include: • Removal of old floricanes immediately after harvest • Promoting rapid drying of the canopy through the use of weed free strips, black plastic, and drip-tape irrigation • Avoiding nutrient and water stresses • Avoiding planting in poorly drained sites

• Chemical controls include: • Applications of phosphonate fungicides (ProPhyt, K- Phite, etc.) are recommended after harvest Understanding Pathogen Biology & Diversity POWDERY MILDEW OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Powdery Mildew

• Infects raspberries, but does not usually affect blackberries • Caused by the fungus Podosphaera aphanis on raspberry • Warm, dry weather with high humidity favors disease • Infected leaves develop light green blotches on the upper surface; in severe cases, leaf distortion and plant stunting can occur

MyIPM App Powdery mildew on leaves Understanding Pathogen Biology & Diversity POWDERY MILDEW OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Management

• Cultural controls include: • Cutting back floricanes to desirable heights in the spring • Promoting good air circulation through proper plant spacing, cane thinning and maintaining narrow rows

• Chemical controls include: • Applications of strobilurin fungicides (Abound, Quilt Xcel, Pristine, and Cabrio) and other effective materials (Rally and Luna Tranquility) Understanding Pathogen Biology & Diversity LEAF SPOTS OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Leaf Spots • Septoria Leaf Spot, Pseudocercospora Leaf Spot, and Cercospora Leaf Spot are important leaf spot diseases that can lead to significant defoliation of blackberries under warm humid conditions. • Heavily infected plants may produce less fruit and lack vitality, making them more susceptible to cold injury.

MyIPM App MyIPM App MyIPM App Septoria Leaf Spot caused by the fungus Mycosphaerella rubi Pseudocercospora rubi Understanding Pathogen Biology & Diversity LEAF SPOTS OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Management

• Cultural controls include: • Increasing air circulation within the planting to promote faster drying of the foliage • Removal of dead or damaged canes as soon as possible after harvest

• Chemical controls include: • Application of fungicides such as Tilt, Abound, Cabrio, Quilt Xcel, and Pristine Understanding Pathogen Biology & Diversity CANEBERRY FUNGAL DISEASES OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Chemical Control of Fungal Diseases Recommendations based upon 2019 SE Regional Caneberry Integrated Management Guide. Trade Active Ingredient FRAC Anthracnose Spur Cane Botrytis Rosette Powdery Rusts Leaf Spots Name MoA Blight Blight Mildew Pristine pyraclostrobin 11 +++++ +++++ +++++ ++++ +++++ +++++ +++++ ++++ boscalid 7 Quilt Xcel azoxystrobin 11 +++++ +++++ +++++ NA +++++ +++++ +++++ +++++ propiconazole 3 Abound azoxystrobin 11 +++++ +++++ +++++ NA +++++ +++++ +++++ ++++ Cabrio pyraclostrobin 11 +++++ +++++ +++++ NA NA +++++ +++++ ++++ Tilt propiconazole 3 NA NA NA +++++ ++++ Rally myclobutanil 3 NA NA NA +++++ +++++ NA Luna fluopyram 7 NA +++++ NA ++++ NA +++++* Tranquility pyrimethanil 9 *Septoria only Switch cyprodinil 9 NA +++++ +++++ NA NA fludioxonil 12 Elevate fenhexamid 17 NA +++++ NA NA NA Iprodione iprodione 2 NA +++ NA NA NA Ph-D polyoxin D zinc salt 19 NA ++ NA NA NA Captan captan M4 +++ ++ ++ ++ NA NA NA Lime calcium polysulfide M2 ++++ ++ ++ NA NA NA NA Sulfur SOUTHEASTERN CANEBERRY SEASONAL SPRAY SCHEDULE

https://berrydealer.com/blackberries/ Example Seasonal Spray Schedule

Delayed Shoots Bloom Petal Cover Preharvest Harvest After Dormant 6” long Fall Sprays harvest Anthracnose & Spur Blight Cane Blight Leaf Spots Rusts & Powdery Mildew Botrytis & Rosette Orange Cane Blotch *Apply after each pruning IF applications remain. Always follow all label rates & instructions. Understanding Pathogen Biology & Diversity CANEBERRY IPM GUIDE OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/ Caneberry IPM Guide Understanding Pathogen Biology & Diversity CANEBERRY IPM GUIDE OUTLINE for Novel Control of Plant Diseases

https://berrydealer.com/blackberries/

Seasonal ‘at a glance’ fungicide spray schedule options for caneberries Developmental Delayed Shoots 6” long Early bloom Full Blooma Petal Fall Cover Sprays Pre-Harvest Harvest After Harvest Stage Dormant till Pre-Bloom (5-10%) Disease Anthracnose, Anthracnose, Anthracnose, Anthracnose, Anthracnose, Anthracnose, Anthracnose, Anthracnose, Leaf Spots (Registered Spur Blight, Cane Blight, Spur Cane Blight, Cane Blight, Cane Blight, Cane Blight, Cane Blight, Cane Blight, (Tilt, Abound, fungicide) Cane Blight Blight, and Leaf Spur Blight, and Spur Blight, and Spur Blight, and Spur Blight, and Spur Blight, and Spur Blight, and Cabrio, Quilt Xcel, (Lime Sulfur Spots (Copper, Leaf Spots Leaf Spots Leaf Spots Leaf Spots Leaf Spots Leaf Spots Pristine) or Copper) Cabrio, Abound, (Cabrio, Abound, (Cabrio, Abound, (Cabrio, Abound, (Cabrio, Abound, (Cabrio, Abound, (Cabrio, Abound, Pristine, Quilt Pristine, Quilt Pristine, Quilt Pristine, Quilt Pristine, Quilt Pristine, and Pristine, and Septoria Leaf Spot Xcel, and Captan) Xcel, and Captan) Xcel, and Captan) Xcel, and Captan) Xcel, and Captan) Captan) Captan) Only (Luna Tranquility) Powdery Mildew Powdery Mildew Powdery Mildew Powdery Mildew Powdery Mildew Powdery Mildew Powdery Mildew (Sulfur, Rally, (Rally, Cabrio, (Rally, Cabrio, (Rally, Cabrio, (Rally, Cabrio, (Rally, Cabrio, (Rally, Cabrio, Powdery Mildew Cabrio, Abound, Abound, Pristine, Abound, Pristine, Abound, Pristine, Abound, Pristine, Abound, Pristine, Abound, Pristine, (Rally, Cabrio, Pristine, Luna Luna Tranquility, Luna Tranquility, Luna Tranquility, Luna Tranquility, Luna Tranquility) Luna Tranquility) Abound, Pristine, Tranquility, Quilt Quilt Xcel) Quilt Xcel) Quilt Xcel) Quilt Xcel) Luna Tranquility, Xcel) Rusts Rusts Quilt Xcel) Rusts Rusts Rusts Rusts (Rally, Abound, (Rally, Abound, Rusts (Rally, Abound, (Rally, Abound, (Rally, Abound, (Rally, Abound, Cabrio, Pristine) Cabrio, Pristine) Rusts (Rally, Abound, Cabrio, Pristine, Cabrio, Pristine, Cabrio, Pristine, Cabrio, Pristine, (Rally, Abound, Cabrio, Pristine, Tilt, Quilt Xcel) Tilt, Quilt Xcel) Tilt, Quilt Xcel) Tilt, Quilt Xcel) Botrytis Botrytis Cabrio, Pristine, Tilt, Quilt Xcel) (Rovral, Nevado, (Rovral, Nevado, Tilt, Quilt Xcel) Botrytis Botrytis Botrytis Botrytis Iprodione, Iprodione, Phytophthora (Rovral, Nevado, (Rovral, Nevado, (Rovral, Nevado, (Rovral, Nevado, Elevate, Switch, Elevate, Switch, Orange Cane Root Rot Iprodione, Iprodione, Iprodione, Iprodione, Pristine, Luna Pristine, Luna Blotch (ProPhyt) (Ridomil, Elevate, Switch, Elevate, Switch, Elevate, Switch, Elevate, Switch, Tranquility, Ph-D Tranquility, Ph-D phosphorous acid- Pristine, Luna Pristine, Luna Pristine, Luna Pristine, Luna and Captan) and Captan) Cane Blight based products Tranquility, Ph-D Tranquility, Tranquility, and Tranquility, Ph-D (see notes) [ProPhyt, K-phite, and Captan) Ph-D and Captan) Ph-D and Captan) and Captan) Rosette Rosette etc.]) (Switch, Abound, (Switch, Abound, Phytophthora Root Rosette Rosette Rosette Rosette Pristine) Pristine) Rot (Ridomil, (Switch, Abound, (Switch, Abound, (Switch, Abound, (Switch, Abound, phosphorous acid- Pristine, Quilt Pristine, Quilt Pristine, Quilt Pristine, Quilt based products Xcel) Xcel) Xcel) Xcel) [ProPhyt, K-phite, etc.]) aCaneberry bloom periods are protracted, so bloom and cover spray can be difficult to define clearly. Do not exceed label rates or spray intervals, but make sure that the pathogens indicated above are addressed with a thorough fungicide program as defined by the cultivar. Understanding Pathogen Biology & Diversity MOYUTLINEIPM A PP for Novel Control of Plant Diseases MyIPM App

MyIPM App • Contains basic disease (and pest) info for Apple, Blackberry, Blueberry, Cherry, Cranberry, Grape, Peach, Pear, & Strawberry MyIPM MyIPM • Includes management and pesticide efficacy info • Available for free download Thank you for your attention! FUNGICIDE RESISTANCE Fungicide Modes of Action (MoA)

• Fungicides work by targeting important enzymes/processes that fungal pathogens need to survive, grow, and reproduce

• Some fungicides target a single enzyme/process within fungal organisms • These are single mode/site of action fungicides

• Other fungicides simultaneously target multiple fungal enzymes/processes • These are multiple modes/sites of action fungicides

• Each fungicide is assigned a class # indicating its MoA by the Fungicide Resistance Action Committee (FRAC) FUNGICIDE RESISTANCE Fungicide Resistance Management

1. As much as possible, utilize fungicides less likely to develop resistance (those with multiple modes of action). 2. Alternate sprays with fungicides from different classes (different modes of action). 3. Tank-mixing of different fungicides is also an acceptable method of resistance management. 4. Follow the label recommendations. Many fungicides are limited to a set number of applications per year in order to improve their long-term survival.