Sunflower Disease Diagnostic Series
PP1727SunflowerDiseaseDiagnosticSeriesSamuel Markell, Extension Plant PathologistNorth Dakota State UniversityRobert Harveson, Extension Plant PathologistUniversity of NebraskaCharles Block, Plant PathologistUSDA, Ames, IAThomas Gulya, USDA Sunflower Pathologist(Retired), Fargo, N.D.Febina Mathew, Field Crops PathologistSouth Dakota State UniversityBlue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
Timeline for sign/symptom occurrenceFOLIARSTEM / WILTHEADPycnia/AeciaV1 EmergenceBacterial head rotRhizopus head rotBacterial stalk rotSclerotinia head rotCharcoal rotDowny mildewPhoma black stemFusarium root/stem rotPhomopsis stem cankerSclerotinia wiltSclerotinia mid-stalk rotVerticillium wiltAlbugo/white rustApical chlorosisAlternaria leaf blightBacterial leaf spotRustPowdery mildewVirusesSeptoria leaf blightR1 BudUrediniaR5 BloomR9 HarvestTeliaRarely occursMay occurFrequently occursReviewed January 2018The NDSU Extension Service does not endorse commercial products or companies even thoughreference may be made to tradenames, trademarks or service names.NDSU encourages you to use and share this content, but please do so under the conditions ofour Creative Commons license. You may copy, distribute, transmit and adapt this work as long asyou give full attribution, don’t use the work for commercial purposes and share your resulting worksimilarly. For more information, visit www.ag.ndsu.edu/agcomm/creative-commons.For more information on this and other topics, see www.ag.ndsu.eduCounty commissions, North Dakota State University and U.S. Department of Agriculture cooperating. North Dakota StateUniversity does not discriminate on the basis of age, color, disability, gender expression/identity, genetic information, maritalstatus, national origin, public assistance status, race, religion, sex, sexual orientation, or status as a U.S. veteran. Directinquiries to the Vice President for Equity, Diversity and Global Outreach, 102 Putnam, (701) 231-7708. This publication will bemade available in alternative formats for people with disabilities upon request, (701) 231-7881.500-8-14, 50-8-15
PP1727-1Sunflower Disease Diagnostic SeriesBacterial head rotPectobacterium carotovorum,subsp. carotovorum and P. atrosepticumFigure 1Figure 2Figure 3
PP1727-1Sunflower Disease Diagnostic SeriesBacterial head rotPectobacterium carotovorum,subsp. carotovorum and P. atrosepticumAUTHORS: Bob Harveson, Sam Markell,Tom Gulya and Charlie BlockSYMPTOMS Coalescing lesions develop watery, soft-rotsymptoms that become dark brown as diseaseprogresses Heads give off an odor of rotting potatoes,and slimy masses of bacterial growth arepresent within infected tissuesFIGURE 1 – Watery lesions forming on heads as aresult of infection through woundsFIGURE 2 – Slimy masses of bacterial growthwithin infected head tissuesFIGURE 3 – Affected tissues dry out and turn blackafter a period of warm, dry weatherFACTORS FAVORING DEVELOPMENT Thunderstorms with hail; insect or bird damageto heads Warm temperatures with high humidity levelsIMPORTANT FACTS Mechanical injury (from insects, birds or hail) isrequired for infection Pathogen is found ubiquitously in soil and isspread by rain splashing and driving winds More common in the U.S southern Great Plainsstates Can be confused with other head rot diseases(Sclerotinia, Botrytis or Rhizopus)Card 1 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-2Sunflower Disease Diagnostic SeriesRhizopus head rotR. stolonifer, R. oryzae (syn. R. arrhizus)and R. microsporusFigure 1Figure 2Figure 3
PP1727-2Sunflower Disease Diagnostic SeriesRhizopus head rotR. stolonifer, R. oryzae (syn. R. arrhizus)and R. microsporusAUTHORS: Bob Harveson, Sam Markell,Charlie Block and Tom GulyaSYMPTOMS First appears on heads as dark spots ofvarying sizes as a result of wounding,followed by a watery, soft rot that later driesand turns dark brown Rhizopus is distinguished from other headrots by the presence of grayish, threadlikemycelial strands within infected heads; smallblack reproductive structures the size of apinhead also may be presentFIGURE 1 – Note wound from hail stone withsubsequent development of watery, soft rotFIGURE 2 – Rotted area of head drying, shrivelingand beginning to shredFIGURE 3 – Grayish fungal strands growingthrough head; reproductive structures (inset)FACTORS FAVORING DEVELOPMENT Thunderstorms with hail; insect or bird damageon head Warm temperatures with high humidity levelsIMPORTANT FACTS Mechanical injury (from insects, birds or hail) isrequired for infection Pathogen is found ubiquitously in soil, andinfective spores are released into the air easily More common in the U.S southern Great Plainsstates Can be confused with bacterial and/orSclerotinia head rotsCard 2 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-3Sunflower Disease Diagnostic SeriesSclerotinia head rotSclerotinia sclerotiorumFigure 1Figure 2Figure 3Figure 4
PP1727-3Sunflower Disease Diagnostic SeriesSclerotinia head rotSclerotinia sclerotiorumAUTHORS: Sam Markell, Tom Gulya,Charlie Block and Bob HarvesonSYMPTOMS Lesions begin as large, soft (mushy),brown areas on the back of heads that turntan-cream, typically odorless White mold (mycelium) and hard blackstructures (sclerotia) form inside head Heads will shred, and disintegration and/ordecapitation may occurFIGURE 1 – Apothecia (grows from sclerotia andproduces ascospores)FIGURE 2 – Soft brown area on the back of headFIGURE 3 – A shredded sunflower with sclerotiaFIGURE 4 – White mycelium and black sclerotia onthe face of a skeletonized sunflower headFACTORS FAVORING DEVELOPMENT Wet soils prior to bloom (facilitates apotheciaproduction) Frequent wetness during or after bloom, includingrain, fog, heavy dew Temperatures 85 F or belowIMPORTANT FACTS The same pathogen causes sclerotinia wilt andsclerotinia mid-stem rot The pathogen can survive for many years in thesoil as sclerotia Management tools are limited Most common in the U.S. northern Great Plains Can be confused with Rhizopus head rotCard 3 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-4Sunflower Disease Diagnostic SeriesBacterial stalk rotPectobacterium carotovorum,subsp. carotovorum and P. atrosepticumFigure 1Figure 2Figure 3
PP1727-4Sunflower Disease Diagnostic SeriesBacterial stalk rotPectobacterium carotovorum,subsp. carotovorum and P. atrosepticumAUTHORS: Bob Harveson, Charlie Block,Sam Markell and Tom GulyaSYMPTOMS Infected stalks soften and dry up, becomingdark brown to black and may split open Plants often lodge under the weight ofmaturing heads A foam may appear on infected tissues as aresult of bacterial-causing fermentation ofsugars in plantFIGURE 1 – Affected tissues blacken and are oftenon petiole axilsFIGURE 2 – Infected stalk splitting longitudinallyFIGURE 3 – Development of a foam on stalkwounds due to bacterial infectionFACTORS FAVORING DEVELOPMENT Thunderstorms with hail Warm temperatures with high humidity levelsIMPORTANT FACTS Mechanical injury (from insects, birds or hail) isrequired for infection Pathogen is found ubiquitously in soil and isspread by rain splashing and driving winds More common in the U.S southern Great Plainsstates Can be confused with other stalk rotsCard 4 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-5Sunflower Disease Diagnostic SeriesCharcoal rotMacrophomina phaseolinaFigure 1Figure 2Figure 3Figure 4
PP1727-5Sunflower Disease Diagnostic SeriesCharcoal rotMacrophomina phaseolinaAUTHORS: Sam Markell, Charlie Block,Bob Harveson and Tom GulyaSYMPTOMS Gray to silver basal lesion starting at thesoil line Premature senescence and plant death Abundant dusty black microsclerotia insidelower stem (visible with a hand lens) Vascular tissue compressed into layersFIGURE 1 – Gray lesion at the base of sunflowerstalksFIGURE 2 – Microsclerotia inside sunflower stemFIGURE 3 – Stem with severe charcoal rotFIGURE 4 – Field with charcoal rotFACTORS FAVORING DEVELOPMENT Field history with charcoal rot, includingsoybeans, corn and other crops Wet weather in spring followed by hot, dryweather in reproductive growth stages Water stress (sandy soil, heat, drought, etc.)IMPORTANT FACTS The same pathogen causes charcoal rot onsoybeans, corn and other crops Infection begins early in the season but manifestsin late reproductive stages if plants are stressed Most common in the U.S. southern and highPlains states Can be confused with Verticillium wilt andSclerotinia wiltCard 5 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-6Sunflower Disease Diagnostic SeriesDowny mildewPlasmopara halstediiFigure 1Figure 2Figure 3
PP1727-6Sunflower Disease Diagnostic SeriesDowny mildewPlasmopara halstediiAUTHORS: Sam Markell, Bob Harveson,Charlie Block and Tom GulyaSYMPTOMS Stunting, leaf chlorosis, white sporulation onunderside of leaf, plant death Horizontal heads when mature Secondary infection: discrete chlorotic leafspots on upper leaf surfaceFIGURE 1 – Stunting and chlorosis (yellowing) fromsystemic infection: Healthy (left), infected (right)FIGURE 2 – Underside (left) and upperside (right)of leaf with systemic infectionFIGURE 3 – Local lesions from secondary infectionFACTORS FAVORING DEVELOPMENT Cold soils and rainfall shortly after plantingleading to waterlogged soil Cool nights with dew or rain (for local lesions viasecondary infection)IMPORTANT FACTS Secondary infections do NOT cause yield loss Pathogen is soil-borne and can survive manyyears in soil Disease is specific to sunflowers Fungicide seed treatments and resistant hybridscan be used for management Can be confused with herbicide damageCard 6 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-7Sunflower Disease Diagnostic SeriesFusarium root andstem rotsFusarium speciesFigure 1Figure 2Figure 3
PP1727-7Sunflower Disease Diagnostic SeriesFusarium root andstem rotsFusarium speciesAUTHORS: Sam Markell, Bob Harveson,Charlie Block and Tom GulyaSYMPTOMS Premature senescence Internal pink, orange, red or purplediscoloration of pithFIGURE 1 – Pink discoloration caused by anunidentified Fusarium speciesFIGURE 2 – Pink streaks caused by Fusariumspp., associated with black microsclerotia ofM. phaseolina (Charcoal rot)FIGURE 3 – Sunflowers infected with FusariumFACTORS FAVORING DEVELOPMENT Water stress (sandy soil, heat, drought, etc.)IMPORTANT FACTS Many Fusarium species have been found tocause damage to sunflowers Many Fusarium species can cause diseaseand/or survive on crop hosts Economic damage is thought to be limited but canoccur Frequently found with Charcoal rot Can be confused with other stalk/wilt diseasesCard 7 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-8Sunflower Disease Diagnostic SeriesPhoma black stemPhoma macdonaldiiFigure 1Figure 2Figure 3Phomopsisstem cankerPhomablack stem
PP1727-8Sunflower Disease Diagnostic SeriesPhoma black stemPhoma macdonaldiiAUTHORS: Sam Markell, Bob Harveson,Tom Gulya and Charlie BlockSYMPTOMS 1- to 2-inch black lesion, usually superficial Lesions centered on petioles Multiple lesions may occur on the same stemFIGURE 1 – Phoma lesions centered on petiolesFIGURE 2 – A sunflower stalk with numerousPhoma lesionsFIGURE 3 – Phoma (bottom black lesion) andPhomopsis (upper brown lesion) occurring on thesame stemFACTORS FAVORING DEVELOPMENT Frequent rainstorms Insects (such as stem weevils) can facilitateinfection Sunflower residue nearby or short rotationIMPORTANT FACTS Rarely economically important Typically the most common stem disease in thenorthern Great Plains Infection begins on leaves and progresses intothe stem Can be vectored by black sunflower stem weevils(Apion) Can be confused with Phomopsis stem cankerCard 8 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-9Sunflower Disease Diagnostic SeriesPhomopsis stemcankerDiaporthe helianthi, D. gulyaeFigure 1Figure 2Figure 3
PP1727-9Sunflower Disease Diagnostic SeriesPhomopsis stemcankerPhomopsis helianthi, P. gulyaeAUTHORS: Febina Mathew, Sam Markell,Tom Gulya, Bob Harveson and Charlie BlockSYMPTOMS Leaf bronzing Large (often greater than 6-inches) brownstem lesion that is centered on petiole Stem will become hollow and is easilypunctured with thumb Premature senescence and/or widespreadlodging may occurFIGURE 1 – Leaf bronzingFIGURE 2 – Stem lesions at different stages ofdevelopmentFIGURE 3 – Stem lesion and lodgingFACTORS FAVORING DEVELOPMENT Frequent rainstorms Infested crop residue and weed hosts nearby, andshort crop rotationIMPORTANT FACTS Infection begins in leaves and spreads into thestem High disease pressure can devastate the crop Most common in the U.S. northern Great Plains Can be confused with Phoma black stem andSclerotinia mid-stem rotCard 9 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-10Sunflower Disease Diagnostic SeriesSclerotiniamid-stem rotSclerotinia sclerotiorumFigure 1Figure 2Figure 3Figure 4
PP1727-10Sunflower Disease Diagnostic SeriesSclerotiniamid-stem rotSclerotinia sclerotiorumAUTHORS: Sam Markell, Charlie Block,Tom Gulya and Bob HarvesonSYMPTOMS Large (greater than 6-inch) tan to manilalesion on the stem, centered on petiole White mold (mycelium) and hard blackstructures (sclerotia) may be visible Stalk may shred at lesion, and plant eventuallywill lodgeFIGURE 1 – Leaf lesion caused by Sclerotiniainfected flowerFIGURE 2 – Sclerotinia lesion with white myceliumFIGURE 3 – Shredded stalk resulting in lodgingFIGURE 4 – Abundant small black sclerotia in ashredded stemFACTORS FAVORING DEVELOPMENT Wet soils before bloom (facilitates apotheciaproduction) Temperatures 85 F or below Prolonged wet canopies (rain, fog, dew, etc.)IMPORTANT FACTS The same pathogen causes Sclerotinia head rotand Sclerotinia wilt Infection begins on leaf when ascosporescolonize senescent leaf tissue, florets or pollen Most common in the U.S. northern Great Plainsstates Can be confused with Phomopsisstem cankerCard 10 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-11Sunflower Disease Diagnostic SeriesSclerotinia wilt/Basal stalk rotSclerotinia sclerotiorumFigure 1Figure 2Figure 3Figure 4
PP1727-11Sunflower Disease Diagnostic SeriesSclerotina wilt/Basal stalk rotSclerotinia sclerotiorumAUTHORS: Sam Markell, Bob Harveson,Charlie Block and Tom GulyaSYMPTOMS Tan to manila basal lesion at soil line White mold (mycelia) and black sclerotia onbasal lesion Whole-plant wilt, basal shredding and lodgingmay occurFIGURE 1 – Tan to manila basal lesion; note whitemyceliumFIGURE 2 – Lodging and shredding (left plant only)caused by Sclerotinia wiltFIGURE 3 – Sclerotia and mycelium on infectedsunflowerFIGURE 4 – Wilted sunflower plantFACTORS FAVORING DEVELOPMENT Field history with Sclerotinia diseases Tight crop rotation with broadleaf cropsIMPORTANT FACTS The same pathogen causes Sclerotinia whitemold on other broadleaf crops Unlike Sclerotinia head and mid-stalk rot, fungusinvades through roots Sclerotia can survive for many years in the soil Most common in the U.S. northern Plains states Can be confused with Verticillium wiltand Charcoal rotCard 11 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-12Sunflower Disease Diagnostic SeriesVerticillium wiltVerticllium dahliaeFigure 1Figure 2Figure 3Figure 4
PP1727-12Sunflower Disease Diagnostic SeriesVerticillium wiltVerticllium dahliaeAUTHORS: Sam Markell, Tom Gulya, Charlie Blockand Bob HarvesonSYMPTOMS Interveinal chlorosis and necrosis starting atlowest leaves and progessing upwards Damaged vascular tissue; initially, a brownring may be present Wilting occurring at bloom, usually in patchesor rows Pith shrunken and black at maturityFIGURE 1 – Sunflower with Verticillium wilt. Noteleaf chlorosis progressing upward.FIGURE 2 – Leaf symptomsFIGURE 3 – Vascular browningFIGURE 4 – External Verticillium lesion on lowerstem (L) and shrunken and blackened pith (R)FACTORS FAVORING DEVELOPMENT Water stress (sandy soil, heat, drought, etc.) Field history with Verticillium wiltIMPORTANT FACTS The same pathogen causes Verticillium wilt onother crops (potatoes, etc.) Can be economically devastating with highdisease pressure Leaf symptoms can be confused with Phomopsisstem canker Can be confused with Charcoal rot andSclerotinia wiltCard 12 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-13Sunflower Disease Diagnostic SeriesAlbugo/White rustFigure 1Figure 2Figure 3
PP1727-13Sunflower Disease Diagnostic SeriesAlbugo/White rustAUTHORS: Sam Markell, Tom Gulya,Bob Harveson and Charlie BlockSYMPTOMS Raised chlorotic pustules up to 3/8 inch indiameter on upper side of leaf Spores on underside of leaf opposite ofchlorotic pustules Lesions on stem, petiole and head are darkand bruiselikeFIGURE 1 – White sporulation on underside of leafFIGURE 2 – Chlorotic lesion on upper surfaceof leafFIGURE 3 – Dark, bruiselike lesion on the stemFACTORS FAVORING DEVELOPMENT Cool nights (50 to 60 F) and warm days(70 to 80 F) Rain splashIMPORTANT FACTS Disease is very rare in the U.S. When found, it often is observed in singlehorizontal layer of leaves across a canopy Can be confused with downy mildew local lesionsand powdery mildewCard 13 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-14Sunflower Disease Diagnostic SeriesAlternaria leaf blightAlternariaster helianthi, Alternaria zinniaeFigure 1Figure 2Figure 3Figure 4
PP1727-14Sunflower Disease Diagnostic SeriesAlternaria leaf blightAlternariaster helianthi, Alternaria zinniaeAUTHORS: Charlie Block, Sam Markell,Bob Harveson and Tom GulyaSYMPTOMS Young leaf spots are small, dark, angular Leaf spots usually are found between majorleaf veins, along leaf margins and tips and willcoalesce Extensive yellowing (chlorosis) occurs,followed by browning and leaf death Defoliation occurs from the ground up Stem lesions are dark, narrow, elliptical andabout ½ to 1½ inches longFIGURE 1 – Characteristic necrotic and chloroticleaf blight lesionsFIGURE 2 – Stem lesionsFIGURE 3 – Lesion coalescence and necrosis nearleaf tipsFIGURE 4 – Yellow leaf spots with little necrosis onresistant cultivarFACTORS FAVORING DEVELOPMENT Rainfall shortly after planting Warm, humid weatherIMPORTANT FACTS Disease development is highly dependent on rainand dew Plants at flowering and seed filling stages moresusceptible than young plants Fungus survives on plant residue Crop rotation and tillage of residue to encouragedecomposition to help manage disease Can be confused with Septoria leaf blight,bacterial leaf spotCard 14 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-15Sunflower Disease Diagnostic SeriesApical chlorosisPseudomonas syringae pv. tagetisFigure 1Figure 2Figure 3
PP1727-15Sunflower Disease Diagnostic SeriesApical chlorosisPseudomonas syringae pv. tagetisAUTHORS: Bob Harveson, Tom Gulya, Sam Markelland Charlie BlockSYMPTOMS Distinctive bright yellow to nearly whitechlorosis of newest leaves New leaves will be unaffected in warm weather May occur on isolated plants, patches orin rows Stunting if plants infected at a young stageFIGURE 1 – Young plant infected systemically; notebright yellow chlorosis and stuntingFIGURE 2 – Plant nearing bud formation (R1)exhibiting systemic chlorosis symptomsFIGURE 3 – Distribution of apical chlorosiscorresponding to low areas of water accumulationin fieldFACTORS FAVORING DEVELOPMENT Wet, cool conditions Water-logged soilsIMPORTANT FACTS Can be observed on plants of all growth stages,but most common on young plants (pre-bloom) Damage is minimal unless young plants areinfected Chlorotic symptoms due to a toxin produced bythe pathogen Related to bacterial leaf spot pathogen Can be confused with fertility problems, downymildew and/or virusesCard 15 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-16Sunflower Disease Diagnostic SeriesBacterial leaf spotPseudomonas syringae pv. helianthiFigure 1Figure 2Figure 3
PP1727-16Sunflower Disease Diagnostic SeriesBacterial leaf spotPseudomonas syringae pv. helianthiAUTHORS: Bob Harveson, Sam Markell, Tom Gulyaand Charlie BlockSYMPTOMS Angular, necrotic spots of varying size Leaf spots form linear lesions that crack andfall out Necrotic spots may be surrounded with yellowhaloesFIGURE 1 – Multiple leaf spots surrounded byyellow halosFIGURE 2 – Small necrotic leaf spots on lowerleavesFIGURE 3 – Coalescing of spots to form linearlesionsFACTORS FAVORING DEVELOPMENT Wounds created by hail, sandblasting and otherforms of mechanical damage Warm temperatures with high humidity levelsIMPORTANT FACTS Often is restricted to lower leaves and, thus, notgenerally economically damaging Can be seed-borne and soil-borne; spread bysplashing rains and high winds Related to apical chlorosis pathogen Can be confused with Alternaria leaf blight andSeptoria leaf blightCard 16 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-17Sunflower Disease Diagnostic SeriesPowdery mildewErysiphe cichoracearumFigure 1Figure 2Figure 3
PP1727-17Sunflower Disease Diagnostic SeriesPowdery mildewErysiphe cichoracearumAUTHORS: Sam Markell, Tom Gulya, Bob Harvesonand Charlie BlockSYMPTOMS White spots of fungal mycelium on upper leafsurface, can be rubbed off easily White mycelium will eventually cover theentire leaf Black specks (cleistothecia) may develop latein seasonFIGURE 1 – Discrete spots of white myceliumforming on a seedlingFIGURE 2 – White spots forming on mature leaf(brown spots are rust)FIGURE 3 – Sunflower leaf completely covered inmyceliumFACTORS FAVORING DEVELOPMENT High humidity Plant maturity and leaf senescenceIMPORTANT FACTS Usually doesn’t appear until after full bloom (R5) Symptoms are often more severe on lower leaves White fluffy growth on the top of leaves and lateonset of disease help distinguish from downymildew Can be confused with local lesions of downymildewCard 17 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-18Sunflower Disease Diagnostic SeriesRustPuccinia helianthiFigure 1Figure 2Figure 3
PP1727-18Sunflower Disease Diagnostic SeriesRustPuccinia helianthiAUTHORS: Sam Markell, Bob Harveson,Charlie Block and Tom GulyaSYMPTOMS Pycnia yellow/orange bump on topside ofleaf (early season) Aecia cluster of orange cups oppositepycnia (early season) Uredia dusty cinnamon-brown pustule(throughout season), spores can be easilyrubbed off, yellow halo common Telia hard black pustule (crop maturity)FIGURE 1 – Pycnia (L) on upper side of leaf andAecia (R) opposite pycnia on underside of leafFIGURE 2 – Uredinia surrounded by yellow halos;note spores on fingerFIGURE 3 – Pustules on stem and petiole (L) andbracts (R)FACTORS FAVORING DEVELOPMENT Frequent leaf wetness; dew, fog, light rain, etc. Temperatures between 55 and 85 F Proximity to wild, volunteer or sunflower residuethat has or had rustIMPORTANT FACTS Sunflower rust is specific to sunflowers (cultivatedand wild) Economic losses can be devastating in epidemics Fungicide threshold 1 percent severity on upperleaves at or before bloom (R5) Found in all U.S. Great Plains states Can be confused with soil splashed on lowerleaves or other foliar diseasesCard 18 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-19Sunflower Disease Diagnostic SeriesSeptoria leaf blightSeptoria helianthiFigure 1Figure 2Figure 3
PP1727-19Sunflower Disease Diagnostic SeriesSeptoria leaf blightSeptoria helianthiAUTHORS: Charlie Block, Bob Harveson,Sam Markell and Tom GulyaSYMPTOMS Circular leaf spots up to ¾ inch in diameter,with dark margins and tan to gray centers Leaf spots often, but not always, surroundedby a narrow yellow halo Fungus survives on plant residue; infectionspreads from bottom leaves upward Mature leaf spots become dotted with blackspecks, or pycnidia, on the upper leaf surfaceFIGURE 1 – Young developing lesionsFIGURE 2 – Mature lesions of Septoria leaf spotFIGURE 3 – Pycnidia visible as black specks insidelarge, round lesions (with hand lens)FACTORS FAVORING DEVELOPMENT Cool temperatures and rain in the spring and fall Symptoms develop most rapidly after flowering,but finding leaf spots on seedlings is common Frequent wetness during or after bloom, includingrain, fog and heavy dewIMPORTANT FACTS Disease tends to go dormant during hot, dryweather Seldom a problem in drier sunflower-productionareas Can be confused with Alternaria leaf blight andbacterial leaf spot. Larger rounded lesions withpycnidia help distinguish Septoria leaf spot fromAlternaria leaf spot.Card 19 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-20Sunflower Disease Diagnostic SeriesVirus DiseasesNebraska mottle/ringspot virus?Sunflower mosaic virusFigure 1Figure 2Figure 3
PP1727-20Sunflower Disease Diagnostic SeriesVirus DiseasesNebraska mottle/ringspot virus? (NMRV?)Sunflower mosaic virus (SMV)AUTHORS: Tom Gulya, Bob Harveson,Sam Markell and Charlie BlockSYMPTOMSNMRV? Begins as small, yellow spots on new foliage Chlorotic ringspots may develop as plantsmatureSMV Leaf mosaic symptomsFIGURE 1 – Greenhouse-inoculated seedlingsshowing small, yellow spots (NMRV?)FIGURE 2 – Late-season field-infected plantshowing chlorotic ringspot symptoms (NMRV?)FIGURE 3 – Typical sunflower mosaic virussymptoms (SMV)FACTORS FAVORING DEVELOPMENT UnknownIMPORTANT FACTS Viruses are not typically an economic problemdue to low incidence Identity of virus pathogen and potential vectorsare unknown in many viruses Sunflower mosaic virus can be seedborne andvectored by aphidsCard 20 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
PP1727-21Sunflower Disease Diagnostic SeriesBroomrapeOrobanche cumana Wallr.Figure 1Figure 2Figure 3Figure 4
PP1727-21Sunflower Disease Diagnostic SeriesBroomrapeOrobanche cumana Wallr.AUTHORS: Daniel T. Ma, Bejing Sunrise Agritec Corp., ChinaGerald Seiler, USDA-ARS Research Botanist, Fargo, N.D., USASYMPTOMS A holoparasitic plant that penetrates thevascular system of sunflower roots The broomrape haustorium penetrates theroots of sunflower absorbing nutrients andwater causing stunting, reduced growth andsevere yield loss Premature senescence and/or widespreadlodging may occurFIGURE 1 – Flowering stalks of broomrapeFIGURE 2 – Mature broomrape plant with capsuleseach containing 1,200 to 1,500 minute black seedsFIGURE 3 – Roots of susceptible plants withattached broomrape (left) and healthy resistantroots (right)FIGURE 4 – Severe broomrape infestation growingfrom the sunflower root systemFACTORS FAVORING DEVELOPMENT Previously infected field Extremely small portable seedsIMPORTANT FACTS There are several different broomrape races: A, B,C, D, E, F, G and H Can be economically devastating under highinfestation pressure The broomrape seeds can survive for many yearsin the soil Most common in southeast Europe, the MiddleEast, southwest Asia and northern China Crop rotation, resistant hybrids and IMI/SU IMI/SU-tolerant hybrids can be used for managementCard 21 of 21Blue R-52 G-64 B-132Green R-39 G-154 B-84Yellow R-240 G-224 B-26Font: Museo Sans 300 and 500
Horizontal heads when mature Secondary infection: discrete chlorotic leaf spots on upper leaf surface FIGURE 1 – Stunting and chlorosis (yellowing) from systemic infection: Healthy (left), infected (right) FIGURE 2 – Underside (left) and upperside (right) of leaf with systemic infection FIGURE 3
Susceptibility or risk predictor biomarkers. Diagnostic biomarker. Individuals at high risk of disease or pre-clinical disease population Diagnostic biomarker. Non-disease population Patients with disease Disease Subtype 1. Disease Subtype 2. Diagnostic biomarker Patients with disease at higher risk of disease-related outcome(s) Prognostic .
sunflower oil is used as a low-saturated fat cooking oil. Linoleic types were the predominant oil-sunflower hybrid produced, but their acreage has decreased. NuSun is currently the predominant oil-type sunflower grown, because seeds produce a healthier oil that contains less saturated
Atherosclerotic Disease is a Pan Vascular Process Coronary Artery Disease (CAD) Non-coronary Atherosclerosis -Peripheral Artery Disease (PAD) -Lower extremity -Upper extremity (subclavian stenosis) -Carotid artery disease -Renal artery disease -Mesenteric artery disease -Aortic aneurysm -Vasculogenic Erectile Dysfunction Vascular disease is
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maintained as a control. Herbicide application in plots amended with sunflower residue had the least total weed count and biomass, which was even better than herbicide used alone. Integration of recommended dose of Treflan with sunflower residue at 1,400 g m-2 produced maximum (987.5 g m-2) aboveground biomass of broad bean, which was 74 and
Vol. 8 No. 3 Density Distribution Sunflower Plots 3 are depicted by a dark sunflower. If the number of observations in a bin is less than
QUIZ 1 Choose only ONE best answer. The term germinate means: a. is full of germs. b. will not grow. c. beginning to sprout. d. ready to plant Which pests can damage a sunflower crop? a. Caterpillars b. Cockatoos c. Snails d. Rutherglen pest e. All of the above A sunflower seed is a. Lo
Biological Control of Sunflower Insect Pests Many natural enemies have made the transition along with their hosts from native to cultivated sunflower Many potential pests held in check by beneficials Natural enemies known for major pest species predators & parasitoids have been studied little known about pathogens
