Title: Pulse and Forage Diseases
1Pulse and Forage Diseases
- Dr. Mary Burrows
- Montana State University Bozeman, MT
2Bacterial blight of pea
Angular lesions
3Ascochyta blight on pea and chickpea
4Fusarium root rot of pea
Fusarium solani f.sp. pisi
Constriction
Reddish-brown
5Fusarium wilt of pea
Fusarium oxysporum f.sp. pisi
- Resistant varieties
- Seed treatment
- Rotation
6Crown rot symptoms in alfalfa
Verticillium, Fusarium, Rhizoctonia,
Phytophthora, Pythium, Phoma, Mycoleptodiscus,
Stagonospora, and Macrophomina
7Crown rot control
- Variety selection
- Promote vigorous growth with proper fertility and
irrigation practices. - Control foliar diseases and insect problems.
- Avoid cutting hay when soils are wet.
- Avoid heavy grazing.
- Control weeds with herbicides and avoid
cultivation practices which damage crowns. - Avoid field sites with heavy or poorly-drained
soils. - Rotate out of alfalfa for 2-3 years.
- Heavy watering in the fall will delay dormancy
- Stop watering end of September
8Stem nematode in alfalfa
White flagging Stunted plants, shortened
internodes Swollen nodes Crinkled leaves
(between veins)
9Stem nematode on alfalfa
- Spread by surface water runoff, irrigation,
wind-blown crop debris, infested hay, soil and
crop debris clinging to equipment, humans and
livestock, and with seed - Prevent introduction of nematodes into a field
- Rotate with a non-host (not alfalfa or sainfoin)
and control alfalfa volunteers 2-4 years - Some resistant lines (not completely resistant)
- Cut infected fields slightly higher and when dry
to reduce spread
10Boron deficiency in alfalfa
- Can result in hollow, corky stems bushy plant
yellow/reddish leaves - Test soil apply fertilizer containing boron
11Alfalfa mosaic virus
- Vectored by aphids
- Symptoms masked by heat
- Wide host range most legumes, many weeds,
potatoes - Transmitted mechanically and in seed
- Makes plants more susceptible to winterkill
12Ergot in grasses used for feed/forage
- Calviceps purpurea
- Sclerotia contaminate seed
- Soilborne sclerotia overwinter
- viable approximately 3 yr in soil or
- longer in stored grain
- Ascospores dispersed by wind and rain infect
florets conidia formed on ovary surface serve as
secondary inoculum - Grain converted into sclerotia
- More abundant during moist growing seasons
13Ergot history (rye)
- 400 B.C. Hippocrates prescribed ergoty grain to
further childbirth - 1039 St. Anthonys fire
- 1692 Salem witch trials
- 1935 LSD was synthesized during research on the
active ingredients in ergot - Ergot contains Lysergic acid
14Ergoty grain is toxic to animals4 forms of
toxicity
- Convulsions
- Gangrene
- Hyperthermia (increased body temperature) in
cattle - Agalactia (no milk) and lack of mammary gland
development, prolonged gestations, and early foal
deaths in mares fed heavily contaminated feed
15Ergot toxicity symptomsdepend on
- Type of ergot consumed
- Ratio of major toxic alkaloids present in the
ergot ergotamine, ergotoxine, and ergometrine - Frequency and quantity of ingestion
- Climactic conditions when ergot was growing
- Species of ergot
- Other impurities in the grain such as histamine
and acetylcholine - Claviceps purpurea is usually associated with
gangrenous ergotism
16Sample Submission
- Accurate Diagnosis depends on a good sample and
symptom description - Enter sample information
into PDIS (Plant Diagnostic
Information System)
17Samples must contain the right material an
entire plant or several plants if practical
Diseases may show up on any part of the plant.
Foliage diseases
Keep most roots and soil intact if possible
Check for injuries, disease on the main stem/trunk
18Dead Plants Tell no Tales
- Avoid dead plants
- Choose plants which show a range of symptoms
moderate to severe
19Packaging Shipping
Good Intentions
20Actual Results
21Packaging and Shipping blunders
Soil on foliage during shipping creates
diseases that were not there when the sample
was collected.
22Packaging and shipping blunders
Sample soup
Dont add water or wrap in wet paper towels
23Good Packaging
- Plastic bag to keep soil on roots
- Dry paper towels to protect leaves from contact
with plastic bag
24Sample Submission
- Try to keep sample as fresh as possible until you
can get it to the county agent refrigerate if
possible. - Include photographs illustrating the problem if
possible.
25http//diagnostics.montana.edu
26- Click on
- Disease Diagnosis Form
27Disease Diagnosis Form
- Print out form
- Fill out question-naire with as much detail as
possible - Place form in box with sample
- Take to County Agent If Possible
28Include photographs illustrating the problem and
field patterns if possible.
29Communication resources
- AgAlerts PDIS.org, or contact Linnea Skoglund
(994-5150 or diagnostics_at_montana.edu) - Montana Ag Fax Fax request to
- 406-994-7600 or send an e-mail to
mburrows_at_montana.edu
30Wiki.bugwood.org/HPIPM
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33Be a First Detector
First Detectors are the front line for early
discovery of new invasive pests.
34What is a high risk pest/pathogen?
- A pest not currently known to occur in the
continental United States exotic
Southern bacterial wilt Ralstonia solanacearum
A pest with limited distribution in the
continental United States, but economically
important if it spreads.
35Select Agents
- Liberobacter africanus, Liberobacter asiaticus
(Citrus greening) - Peronosclerospora philippinensis (Philippine
downy mildew ) - Ralstonia solanacearum, race 3, biovar 2
(Southern wilt) - Sclerophthora rayssiae var. zeae (Brown stripe
downy mildew ) - Synchytrium endobioticum (Potato wart disease)
- Xanthomonas oryzae pv. Oryzicola (Rice leaf
streak) - Xylella fastidiosa (citrus variegated chlorosis
- strain)
36High Consequence Pests (diseases) of Concern for
Great Plains region (some examples)
- Wheat karnal bunt, rice blast, seed gall
nematode - Potato potato wart, golden nematode, pale cyst
nematode, potato rot nematode, phytoplasmas, wilt - Stone fruits plum pox virus
37response
diagnosis
detection
What happens when a high risk pest is found?
APHIS SDAs
APHIS
38Your role as a First Detector
- Receive NPDN First Detector training
- Take online modules (http//cbc.at.ufl.edu)
- Attend classes like this one
- Be alert to the unusual or different
- Know how to properly submit a suspect high risk
pest or pathogen sample - Know how to maintain chain of custody and
communication when submitting a suspect sample - Be placed on a national notification registry of
First Detectors if you wish to - Receive pest alerts and other relevant updates
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40Informational sites
- Highplainsipm.org
- Greenbook.net Pesticide labels
- NDSU fungicide guide
- http//www.ag.ndsu.edu/pubs/plantsci/pests/pp622/
pp622.pdf - MontGuides http//www.montana.edu/wwwpb/pubs/inde
xag.html - Wheat diseases of Montana
- http//scarab.msu.montana.edu/Disease/DiseaseGuid
ehtml/
41Forage Crop Diseases
- Disease triangle
- Best management practices
- Expected yield hit
- What factors would favor/disfavor disease
Host
Pathogen
Environment