Transcript plant bacterial and fungal diseasesx

• To identify plant diseases common to
horticulture and agronomic crops.
• To reveal the impact plant diseases can have
on fruits, plants and agricultural crops.
• To analyze methods of plant disease control.
Table of Contents
• Introduction to Diseases
• Bacterial Diseases
o A-B
o C-Z
• Is any condition interfering with normal growth
and development
• Is caused by living or non-living agents
• Can affect any area on a plant
• Are referred to as plant pathogens
o anything causing harm to plants
• Include microorganisms, such as:
o fungi
o bacteria
Fun Fact :
Another term for living agent is
biotic agent.
• Spread from plant-to-plant via wind,
insects, rain, soil and machinery
• Can be transmitted by seeds
• Can be waterborne
• Are most common and easiest to
treat
• Treatment can include:
o sanitation
o reduce watering
o increase air flow
•
•
•
Usually start with spotted or discolored leaves
and stems
o dry, brown margins and dead tissue or
necrotic lesions
Are controlled with dusts or sprays
Are nearly impossible to eliminate if not
treated immediately, especially soil-borne
disease
• Are a form of mold
• Are commonly found in damp, moist, shaded
places
• Affect leaves, stems, buds, flowers and fruits
o leaves will turn pink, blue or purple and
drop prematurely
• Are usually white, gray, green or black
• Includes four stages:
o spore production
o spore
o spore germination
o hyphal growth
• Are easier to prevent rather than cure
• Enter plants through wounds or natural
openings, such as the stomata
• Easily occur under the following conditions:
o high humidity
o poor air circulation
o irregular watering
o poor soil drainage
o fluctuating temperatures
• Spread by:
o infected seeds
o animals and birds
o irrigation water and rain
o machinery
• Have symptoms such as:
o leaf spots
o blights
o wilting
• Include:
o environmental stress
on plants, such as:
• air pollution
• drought
• hail
Fun Fact :
• wind
Non-living agents are
o cultural care
also referred to as
abiotic agents.
o toxic chemicals
o viruses
• Are microscopic, infectious agents
consisting of a protein coat surrounding
nucleic acid
• Multiply in cells of living hosts
• Are recognized by the following
symptoms:
o leaf curling
o leaf discoloration
o ring spots on leaves
o stunted growth
• Can be prevented by:
o planting disease-resistant varieties
o controlling pests carrying viruses
o removing and destroying infected
plants
o controlling weeds
o handling foliage when dry
• Can be spread by:
o infected insects, plants and
microorganisms
• Are specific pesticides for fungal diseases in
plants
• Are used to:
o control fungi in crop stands
o increase productivity of crops
o increase storage life of plants and
produce
• Should be applied as soon as symptoms occur
or with coated seeds
• Can be applied in the following forms:
o dust
o gas
o granule
o liquid
• Are applied on:
o bulbs
o foliage
o harvested produce
o roots
o seeds
o soil
1. Which area of a plant can be affected by disease?
A. All areas
B. Only the stem
C. Only roots
D. Only leaves
2. What is another term used when referring to a living agent?
A. Living specimen
B. Bacterial agent
C. Fungal agent
D. Biotic agent
3. All but which of the following are treatment methods for fungal diseases?
A. Increasing air flow
B. Increasing water
C. Reducing water
D. Sanitation
4. Which of the following can NOT spread bacterial diseases?
A. Wind
B. Infected seeds
C. Birds
D. Machinery
5. What type of disease is the easiest to treat?
A. Bacterial
B. Fungal
C. Viruses
D. All are equally treatable
• Scientific Name: Pseudomonas lachrymans
• Characteristics:
o infects cucumbers, melons and squash
o usually appears on fruit in middle stage of
development
o causes small, saturated areas to
develop on stems and fruit
• areas appear tan, but turn gray
and white as disease progresses
o forms holes in leaf as dead tissue falls
off
o causes lesions between water-saturated
veins
• Environmental conditions:
o humidity
o strong wind
o splashing water
o infected irrigation water
• Prevention methods:
o choose plant varieties suitable for climate
o practice crop rotation
o destroy infected plants
o avoid overhead watering systems
o provide proper amounts of fertilizer
• Treatment methods:
o fungicides which contain:
• copper hydroxide-based, such as
Champion®, Kocide® 101 and
Bordeaux® mixture
• Scientific Name: Xanthomonas campestris
• Characteristics:
o affects a variety of crops, such as:
• lima beans
• soybeans
• snap beans
o forms saturated spots on leaves
• spots turn pale-green or yellow then
dark-brown
o causes leaves to die and fall
o causes stems to wilt as disease
progresses
• Environmental conditions:
o high humidity
o wet weather
• Prevention methods:
o use crop rotation
o provide space for air circulation
o use seeds from non-infected plants
o avoid handling plants when wet
• Treatment methods:
o fungicides which contain:
• copper hydroxide, as found in
Champ® or Kocide® 200
• Scientific Name: Xylella fastidiosa
• Characteristics:
o commonly affects trees, such as:
o elm
o maple
o walnut
o dries leaves out
o turns margins brown
o affects outer leaves severely
• Prevention methods:
o deep root systems
o prune regularly
o water regularly
• soil should be deeply
watered
• fertilize trees of low vigor
• Treatment methods:
o no available treatment
• follow prevention methods
• Scientific Name: Erwinia carotovora
• Characteristics:
o affects many vegetable plants, such as:
• carrots
• corn
• onions
• potatoes
o affects potatoes in the following ways:
• tissue becomes saturated and wet
• rotten tubers acquire odor in later
stages of disease
o affects onions in the following ways:
• symptoms occur inside onion
during storage
• infected bulbs are soft and palebrown
• contaminated onions produce a
foul odor
• infected onions have a soft neck
o causes taproots of carrots to decay and
become soft
o affects corn in the following ways:
• uppermost leaf tips dry out
• decay starts at top of plant and
moves down
• stalks turn brown, become watersoaked and eventually fall over
• produces an odor
• Environmental conditions:
o warm weather
o humidity
o high level of soil moisture
o insect wounds
• Prevention methods:
o use crop rotation
o handle gently
o mix compost with soil to increase
beneficial bacteria populations
• Treatment methods:
o seed treatments which contain:
• thiophanate-methyl or thiophanatemethyl, with the addition of
mancozeb, such as Tops® MZ®
• Scientific Name: Xanthomonas campestris pv.
vesicatoria
• Characteristics:
o irregular spots on tomato plants
and pepper leaves
o younger leaves more susceptible
o weakens plants
o causes decay
o common in midwestern and eastern
United States
• Environmental conditions:
o very warm, wet conditions
• Prevention methods:
o use disease-free seeds
o remove weeds
o fertilize
o use crop rotation
o provide space for air circulation
o use drip irrigation and soaker hoses to
maintain dry foliage
o cover soil with mulch
o remove infected plants
• Treatment methods:
o fungicides which contain:
• mancozeb and copper, such as
Yates™
• Scientific Name: Ralstonia solanacearum
• Characteristics:
o leaves turn brown as disease spreads
o streaking in vascular tissue
o causes cucumber and squash leaves to
droop
o effects young plants first
o results in plant death
o bacteria clogs vascular system
• Environmental conditions:
o infected insects feed on leaves
• Prevention methods:
o plant wilt-resistant varieties
o sustain proper plant health
o remove infected plants
• Treatment methods:
o no available treatment
• follow prevention methods
• Scientific Name: Pectobacterium carotovorum
var. atrosepticum
• Characteristics:
o forms dark spots on base of
stems and roots in cabbage
plants
o plants turn yellow, wilt and die
o spread by rain, wind and human
activity
• Environmental conditions:
o cool, moist weather
• Prevention methods:
o provide space for air circulation
o remove weeds
o remove infected plants
o use crop rotation
o prevent injury to crop
o choose resistant cultivars
• Treatment methods:
o fungicides which contain:
• iprodione, such as Rovral®
• Scientific Name: Agrobacterium tumefaciens
• Characteristics:
o occurs on roots and stems of many plants
• most destructive in fruit trees and
shrubs
• commonly seen in roses
o forms galls at crown and lateral roots
• galls are one-quarter inches to one
foot in diameter
• young are tan and have a soft
surface
• mature are black and have a very
hard surface
o stunts plant growth
o turns leaves yellow or brown
• Environmental conditions:
o cool, humid weather
• Prevention methods:
o avoid plant injury
o avoid contaminated tools
o inspect plants carefully and regularly
o destroy infected plants
o plant gall-resistant varieties
• Treatment methods:
o products which contain:
• meta-cresol, such as Gallex®
• Scientific Name: Erwinia amylovora
• Characteristics:
o destroys trees and shrubs
o common among fruit trees
o identified by tan liquid seeping out of
branches and twigs
• liquid darkens with air exposure,
called “bacterial ooze”
o causes infected flowers to wilt and turn
black or brown
• dead, blackened leaves will cling to
branches during spring
o forms orange-red streaks on bark
o dries out and kills wood
• Environmental conditions:
o wet, humid weather
• Prevention methods:
o avoid heavy pruning
o monitor trees regularly
o remove infected plants
o plant resistant varieties
o provide adequate fertilization
• Treatment methods:
o fungicides which contain:
• copper products, such as
Bordeaux®
• Characteristics:
o known as cecidia
o abnormal tissue growths
o formed by microorganisms and insects
• insects cause galls when laying
eggs or feeding
o form on buds, leaves, flowers, twigs, bark
and roots
o unattractive, but causes no harm
o appear in two forms: open or closed
• open are formed by insects with
piercing mouthparts
• closed are formed by insects with
mandibles
• Environmental conditions:
o cool, humid weather
• Prevention methods:
o use insecticides to control insect
populations
• Treatment methods:
o no available treatment
• follow prevention methods
• Scientific Name: Streptomyces scabies
• Characteristics:
o appears on skin of potato tubers
• turns dark brown or black
o forms large circular scabs on potatoes,
called “scab lesions”
o usually noticed after harvest or late in
growing season
o reduces marketability of potatoes
o transmitted by wind and water
• Environmental conditions:
o soil with high organic matter
o coarse, textured soils
o warm, dry weather
o wounded plants
• Prevention methods:
o use crop rotation
o do not use compost mixes
o keep soil cool and moist
o plant disease-resistant varieties
• Treatment methods:
o before planting, treat seed tubers with a
seed fungicide which contain:
• captan or mancozeb
1. On which plant does angular leaf spot NOT occur?
A. Cucumbers
B. Squash
C. Melons
D. Corn
2. Under which environmental conditions does bacterial blight spread?
A. High humidity
B. Low humidity
C. High temperatures
D. High winds
3. Which prevention method is NOT used to prevent bacterial blight?
A. Crop rotation
B. Proper irrigation
C. Use non-infected seeds
D. Provide space for air circulation
4. Which of the following can be used to treat bacterial spot?
A. Copper
B. Sulfur
C. Zinc
D. Lime
5. Which region of the country is bacterial spot most prevalent in?
A. Northwest
B. Midwest
C. Southwest
C. South
6. Which environmental conditions are best for blackleg to occur?
A. Cool, moist weather
B. Warm, wet weather
C. Cool, dry weather
D. Warm, dry weather
7. Which part of the plant is affected by crown gall?
A. Leaves
B. Thorns
C. Roots
D. Fruit
8. Which plant is crown gall commonly seen in?
A. Roses
B. Bermuda grass
C. Oak trees
D. Pine trees
9. How does gall harm the plant?
A. Wilts leaves
B. Destroys fruit
C. Removes fluids
D. Causes no harm
10. Potato scab is usually noticed when?
A. Before planting
B. During planting
C. During growth
D. After harvest
1. Which type of diseases can be waterborne?
A. Fungal
B. Bacterial
C. Viral
D. Non-living
2. Environmental stress on a plant is what type of pest?
A. Non-living
B. Viral
C. Fungal
D. Bacterial
3. Which type of disease is commonly found in damp, moist and shaded areas?
A. Bacterial
B. Fungal
C. Viruses
D. Mildews
4. Which symptom is NOT caused by bacterial diseases?
A. Blights
B. Leaf spots
C. Mildews
D. Wilting
5. Under which environmental condition does angular leaf spot occur?
A. Dry climates
B. Strong wind
C. Cold weather
D. Standing water
6. Which tree is NOT commonly affected by bacterial leaf scorch?
A. Elm
B. Pecan
C. Maple
D. Walnut
7. Which of the following is NOT a characteristic of bacterial soft rot?
A. Foul odor
B. Tissues become saturated
C. Leaf tips dry out
D. Bacteria clogs vascular system
8. How can bacterial wilt be treated?
A. Fungicides
B. Proper irrigation
C. Crop rotation
D. No treatment available
9. On which part of the plant does fireblight cause orange-red streaks?
A. Leaves
B. Fruit
C. Bark
D. Roots
10. How can galls be treated?
A. Remove by hand
B. Herbicides
C. Fungicides
D. No treatment available
Biggs, A. R. & Hickey, K. D. (1997). Apple Scab. Retrieved from
http://www.caf.wvu.edu/kearneysville/disease_descriptions/omapsca
b.html
North Dakota State University. McMullen, M. & Stoltenow, C. (May
2002). Ergot. Retrieved from
http://www.ag.ndsu.edu/pubs/plantsci/crops/pp551w.htm
Cranshaw, W.S. (August 29 2011). Insect and Mite Galls. Retrieved
from http://www.ext.colostate.edu/pubs/insect/05557.html
National Arborists. (2011). Apple Scab. Retrieved from
https://natlarb.com/html/apple_scab.html
Vann, S. Ph.D.(2006) Plant Diseases. Retrieved from
http://www.aragriculture.org/diseases/image_library/default.htm
United States Department of Agriculture. Retrieved from
http://www.ars.usda.gov/is/graphics/photos/
Kansas Department of Agriculture. Retrieved from
http://www.ksda.gov/plant_protection/
Broome, J. C. & Ingels, C. A. Produced by UC Statewide IPM
Program, University of California. (January 2011). Peach Leaf Curl.
Retrieved from
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7426.html
Grove, Gary, Ph.D., Washington State University Extension. Apple
Scab. Retrieved from
http://gardening.wsu.edu/library/tree005/tree005.htm
Rosenthal, S., Grau, C. & Hudelson, B. (December 28, 2005). Ergot.
Retrieved from
http://pddc.wisc.edu/factsheets/Full%20Color%20PDF%20Format/Er
got.pdf
Schuster, J. (2011). Cedar Apple Rust. Retrieved from
http://urbanext.illinois.edu/focus/cedarapplerust.cfm
Oklahoma State University. Entomology and Plant Pathology.
Retrieved at http://entoplp.okstate.edu/ddd/
University of Illinois. Field Crop Diseases. Retrieved from
http://cropdisease.cropsci.illinois.edu/index.html
Stack, R. W. & Lamey, H. A. (November 1995). Deciduous Tree
Diseases. Retrieved from
http://www.ag.ndsu.edu/pubs/plantsci/hortcrop/pp697-1.htm
Lamey, H. A., Ash, C. L., & Stienstra, W. C. (July 1996). Lawn
Diseases. Retrieved from
http://www.ag.ndsu.edu/pubs/plantsci/landscap/pp950w.htm#fair
y
PAN Germany, OISAT. Retrieved from
http://www.oisat.org/pests/diseases/viral.html
McGrath, M.T. (2004). What are Fungicides. The Plant Health
Instructor. Retrieved from
://www.apsnet.org/edcenter/intropp/topics/Pages/Fungicides.asp
x
Iowa State University, Entomology Department. Retrieved from
http://www.ent.iastate.edu/imagegal/plantpath/
University of Kentucky, Department of Plant Pathology.
Retrieved from
http://www.ca.uky.edu/agcollege/plantpathology/extension/links.
html
Byers, J. A. (2006). Gall-Making Insects. Retrieved from
http://www.chemical-ecology.net/insects/gallmake.htm
Production Coordinators
Kelly Harkey
Baron Bartels
Layton Norwood
Assistant Brand Manager
Olivia Mitchell
Graphic Designer
Melody Rowell
Technical Writer
Jessica Odom
Production Manager
Maggie Bigham
V.P. of Brand Management
Clayton Franklin
© MMXIII
CEV Multimedia, Ltd.
Executive Producer
Gordon W. Davis, Ph.D.