2 Plant Health Care Fungal Pathogens Lecture
- 1. Plant Health Care Fungal Pathogens Lecture
- 3. Fungi Majority of fungi are NOT plant pathogens Primarily survive on non-living organic material, are called SAPROPHYTES The non-reproductive "body" of most fungi (called the vegetative phase) is composed of a mass of a fungal threads called HYPHAE (singular = HYPHA ) This mass of hyphae is called a MYCELIUM (plural = MYCELIA ). While an individual hypha is microscopic, mycelia are often visible with the naked eye.
- 4. HYPHAE (singular = HYPHA ) are the threadlike structures that comprise the major body of a fungus. You can think of a hypha as a long tube. Many hyphae in a mass are called MYCELIUM (plural = MYCELIA ).
- 5. Fungi Identification Most fungi produce hyphae, as the one shown here, that have CROSS WALLS (Septa) (partitions dividing the tubes into individual cells) presence or absence of cross walls can be important in distinguishing and identifying some plant pathogenic fungi.
- 6. Fungal Fruiting Structures Fungi produce a wide range of reproductive structures (generically called FRUITING BODIES ) Within fruiting bodies, a fungus produces spores
- 7. Powdery Mildew Fruiting Bodies Black – fruiting body Red – sacks Blue – spores Green - appendages
- 10. Group I – Primarily Affecting Leaves Coryneum Blight Early Blight Fusarium Wilt Marssonina Leaf Spot – example of fungal leaf spot Powdery Mildew Rust Sooty Mold
- 11. Blight Symptoms When spots or lesions enlarge and merge so that large areas of a leaf are necrotic and diseased, then we call this a BLIGHT .
- 12. Coryneum Blight Affects stone fruits in Colorado ‘ Shothole’ disease Affects fruit, stems, and leaves Small purple spots, fallout
- 13. Coryneum Blight Fruit symptoms Rough scab-like distortions Sunken grayish areas Overwinters on buds or twigs Early wet season
- 15. Coryneum Blight Affects peaches, nectarines, sweet cherries, plums – Prunus species Overwinters on buds or twigs Early wet season promotes disease Hard to eliminate with pesticides Fall clean up, good air circulation, prune out damaged tissue
- 16. Early Blight Tomato early blight target-like leaf spot Tomato early blight target like leaf spots Starts with small spots
- 17. Early Blight
- 18. Early blight (Alternaria) Affects many vegetables Leaves, stems, fruit Plant resistant varieties Remove and destroy
- 19. Early Blight Symptoms Symptoms – brown on edges, leaves Small holes, leaves missing Brown spots – concentric rings Cankers on stems Leaf curl Wilt
- 20. Fusarium Wilt of Tomato
- 21. Fusarium Wilt Leaves turn yellow Early leaf drop Stems droop Yellow leaf patches Can be on one side of a plant
- 22. Fusarium Wilt Occurs in warm weather Soil borne Plant resistant varieties Remove and destroy
- 23. Fusarium Wilt of Tobacco
- 25. Fusarium Wilt
- 26. Fungal Leaf Spot Redbud
- 27. Marssonina leaf spot of Aspen
- 28. Marssonina Leaf Spot of Poplar
- 29. Marssonina leaf spot Early spring Affects poplars and cottonwoods, esp. aspen Fall clean up Prune out damage to stems Can lead to cankers and die back if severe
- 30. Powdery Mildew The white that you see is a combination of hyphae and asexual spores. ‘Powdery Mildew’ is a group of closely related fungi Host specific High humidity is the key
- 31. Powdery Mildew on Lilac
- 32. Powdery Mildew on Pumpkin
- 34. Powdery Mildew overwinters in Apple buds Overwintering apple powdery mildew deforms the buds creating a feathered appearance (right) rather than a smooth round healthy bud (left).
- 35. Powdery mildew on apple foliage Powdery mildew symptoms on apple foliage (right), notice upward curling of leaves and white appearance. Healthy foliage (left).
- 36. Powdery Mildew Affects leaves Occurs mid to late summer when evenings are cool and days are hot Pesticides include sulfur, baking soda Dislikes wet leaf surface More abundant on lower leaves Also occurs on fruit
- 37. Powdery Mildew Fall clean up Good air circulation
- 38. Rust rusty-orange, powdery PUSTULES Easily rubbed off Often requires two hosts
- 39. Rust Produces gelatinous masses & cups of discolored and distorted tissue Remove and destroy seriously affected plants Good air circulation, resistant varieties Avoid wetting leaves Don’t plant both hosts together
- 40. Rust Affects leaves – pale yellow spots, drop early Stems Fruit have yellow spots that turn orange Fungicides, copper, sulfur Avoid nitrogen fertilizer
- 41. May Apple Rust
- 42. Rose Rust
- 43. Rust on Spruce
- 44. Rust on Lawn & Shoes
- 45. Cedar Apple Rust
- 48. Cedar Apple Rust Also called Juniper – Hawthorne Rust Plant alternate hosts 4 miles apart Destroy the galls before winter Copper based fungicides, minimal effect
- 50. Sooty Mold Control insect producing the honeydew Can be wiped off Black or gray-green non-parasitic fungus
- 51. Scale & Sooty Mold on Pine
- 53. Group II – Primarily Affecting Stems Anthracnose Botrytis Blight Cytospora Canker Verticillium Wilt
- 54. Cankers Lesions that occur on the stems of herbaceous plants or on the trunks and branches of woody plants are called CANKERS Often cankers are sunken and discolored, or, as in this example of a canker disease on honey locust, the outer bark layer has totally fallen away. http://www.plantpath.wisc.edu/PDDCEducation/MasterGardener/General/Slide15.htm
- 55. Anthracnose of Maple & Sycamore Enlarged leaf vein
- 56. Anthracnose
- 58. Anthracnose Affects leaves, stems, fruit, entire plant Occurs early spring Symptoms appear on young leaves as they emerge (confused with frost damage) Older leaves turn brown Dead areas occur along the leaf veins Ends of twigs may be killed back 8-10 iches
- 59. Anthracnose Cancers may develop on the tree trunk and main branches Fall clean up, improve air circulation Plant resistant varieties Prune out damage
- 60. Botrytis Blight
- 61. Botrytis Blight Grey mold disease affects many plants Cool rainy spring, temp around 60 Can affect every part of a plant except the roots Remove and destroy damaged tissue Avoid wet leaf surfaces Fungal sprays
- 62. Cytospora Canker in Aspen
- 63. Cytospora Canker Orange-stained bark and sap flow are indicative of early cytospora canker infection
- 64. ` As infected tissue dies, pimple-like fruiting bodies called pycnidia form
- 65. Cytospora Canker Under moist conditions small orange tendrils of a jellylike material oozes from the pycnidia.
- 66. Cytospora Canker in Spruce
- 67. Cytospora Canker Symptoms Yellowing, wilting and dieback of new shoots Bark discoloration Gummosis Orange or amber colored ‘ooze’ Cankers ‘Wound parasite’
- 68. Cytospora Canker Common on willow, aspen, cottonwood, maple, stone fruits, spruce Avoid stress & injury Prune out damage if you can without creating another wound
- 69. Fungal Canker Nectria galligena on apple
- 70. Lantern canker on birch with nail
- 71. Vascular Wilt Vascular wilt pathogens invade the plant's water-conducting tissue (called the XYLEM ). These pathogens either cause blockages in the xylem themselves or the plant itself blocks off the xylem in an effort to localize the pathogen.
- 72. Verticillium Wilt Cool weather Early in the season Enters through wounds Affects wide range of woody & herbaceous plants Tomato, alfalfa, raspberries, strawberries, potatoes, eggplant
- 73. Symptoms Slight yellow on foliage Discoloration of wood Cankers may form on branches Staining of sapwood Leaves V shaped yellowing, widest on leaf margins Stems droop Plant dies
- 74. Prevention Soil borne – soil sterilization (?) Resistant varieties Prevent wounding
- 75. Verticillium Wilt of Maple VASCULAR DISCOLORATION or BROWNING
- 77. Verticillium Wilt – Tomato
- 78. Group III - Primarily Affecting Roots Pythophera Rhizoctonia
- 80. Phytophthora Root Rot Soil borne and seed borne Disbursed by splashing, heavy rains or irrigation and run off from plant to plant Need well drained soil
- 81. Phytophthora symptoms Dark streaks up the stem Stunting Reduced roots Dead feeder roots Death of plant
- 82. Phytophthora Root Rot Bordeaux mix when the weather is cool Destroy infected plants Prune out damaged material Purchase phytophthora free plants
- 85. Phytophthera in Soy Beans
- 86. Rhizoctonia
- 87. Rhizoctonia Affects roots & lower stems Roots turn black or charcoal colored Occurs in spring Affects young plants or stressed older plants Soil borne
- 89. Group IV – Fungal Diseases of Turf Ascochyta Leaf Blight Dollar Spot Fairy Rings Melting Out Disease Necrotic Ring Spot
- 92. Ascochyta Leaf Blight Affect tips of turf Change watering practices Aerate the turf Affects Kentucky Bluegrass
- 94. Fairy Rings
- 95. Melting Out Disease of Turf
- 96. Melting Out Occurs in spring Band of discolored tissue in the middle of the leaf blade Crowns can be rotten or red Improve watering practices Broad spectrum fungicides Plant resistant varieties
- 98. Necrotic Ring Spot Mid spring through fall Affects Kentucky Bluegrass Plant resistant varieties Kills the crowns of the turf Apply fungicide Change watering practices
- 99. Fungi for Test Marssonina Leaf Spot Powdery Mildew Botrytis Blight Cytospora Canker Verticillium Wilt Phytophthora Root Rot Rhizoctonia Aschochyta Leaf Blight Dollar Spot
- 100. Marssonina leaf spot of Aspen
- 101. Marssonina Leaf Spot of Poplar
- 102. Marssonina leaf spot Early spring Affects poplars and cottonwoods, esp. aspen Fall clean up Prune out damage to stems Can lead to cankers and die back if severe
- 103. Powdery Mildew The white that you see is a combination of hyphae and asexual spores. ‘Powdery Mildew’ is a group of closely related fungi Host specific High humidity is the key
- 104. Powdery Mildew on Lilac
- 105. Powdery Mildew on Pumpkin
- 107. Powdery Mildew overwinters in Apple buds Overwintering apple powdery mildew deforms the buds creating a feathered appearance (right) rather than a smooth round healthy bud (left).
- 108. Powdery mildew on apple foliage Powdery mildew symptoms on apple foliage (right), notice upward curling of leaves and white appearance. Healthy foliage (left).
- 109. Powdery Mildew Affects leaves Occurs mid to late summer when evenings are cool and days are hot Pesticides include sulfur, baking soda Dislikes wet leaf surface More abundant on lower leaves Also occurs on fruit
- 110. Powdery Mildew Fall clean up Good air circulation
- 111. Group 2 Affecting Stems Botrytis Blight Cytospora Canker Verticillium Wilt
- 112. Botrytis Blight
- 113. Botrytis Blight Grey mold disease affects many plants Cool rainy spring, temp around 60 Can affect every part of a plant except the roots Remove and destroy damaged tissue Avoid wet leaf surfaces Fungal sprays
- 114. Cytospora Canker in Aspen
- 115. Cytospora Canker Orange-stained bark and sap flow are indicative of early cytospora canker infection
- 116. Cytospora Canker As infected tissue dies, pimple-like fruiting bodies called pycnidia form
- 117. Cytospora Canker Under moist conditions small orange tendrils of a jellylike material oozes from the pycnidia.
- 118. Cytospera Canker in Spruce
- 119. Cytospora Canker Symptoms Yellowing, wilting and dieback of new shoots Bark discoloration Gummosis Orange or amber colored ‘ooze’ Cankers ‘Wound parasite’
- 120. Cytospora Canker Common on willow, aspen, cottonwood, maple, stone fruits, spruce Avoid stress & injury Prune out damage if you can without creating another wound
- 121. Fungal Canker Nectria galligena on apple
- 122. Lantern canker on birch with nail
- 123. Verticillium Wilt Cool weather Early in the season Enters through wounds Affects wide range of woody & herbaceous plants Tomato, alfalfa, raspberries, strawberries, potatoes, eggplant
- 124. Symptoms Slight yellow on foliage Discoloration of wood Cankers may form on branches Staining of sapwood Leaves V shaped yellowing, widest on leaf margins Stems droop Plant dies
- 125. Prevention Soil borne – soil sterilization (?) Resistant varieties Prevent wounding
- 126. Verticillium Wilt of Maple VASCULAR DISCOLORATION or BROWNING
- 127. Verticillium Wilt
- 128. Verticillium Wilt – Tomato
- 129. Group III - Primarily Affecting Roots Phytophthora Rhizoctonia
- 131. Phytophthora Root Rot Soil borne and seed borne Disbursed by splashing, heavy rains or irrigation and run off from plant to plant Need well drained soil
- 132. Phytophthora symptoms Dark streaks up the stem Stunting Reduced roots Dead feeder roots Death of plant
- 133. Phytophthora Root Rot Bordeaux mix when the weather is cool Destroy infected plants Prune out damaged material Purchase phytophthora free plants
- 136. Phytophthera in Soy Beans
- 137. Rhizoctonia
- 138. Rhizoctonia Affects roots & lower stems Roots turn black or charcoal colored Occurs in spring Affects young plants or stressed older plants Soil borne
- 139. Rhizoctonia lesions
- 140. Group IV – Fungal Diseases of Turf Ascochyta Leaf Blight Dollar Spot
- 142. Ascochyta Leaf Blight Affect tips of turf Change watering practices Aerate the turf Affects Kentucky Bluegrass
- 145. Dollar Spot Appears as tan lesions on the turf blade Surrounded by reddish brown borders Indicates nitrogen deficiency and prolonged wetness Overwinters in thatch and soil
- 147. Id from Photographs