Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
DISEASE EFFECTS OF
PUSHING CROP ROTATIONS
WITH PULSE CROPS
Sherrilyn Phelps, MSc., P.Ag., CCA, Agronomy Manager,
Jan 24, 2018 – MABA/MGEA
ACKNOWLEDGEMENTS
Dr. Barb Ziesman, Saskatchewan Agriculture
Dr. Syama Chatterton, AAFC Lethbridge
Dr. Sabine Banniza, University of Saskatchewan
TOPICS TO COVER
•Interest in pulse crops
•Pulse crop acres in Northern Great Plains
•Rotations
•Diseases influenced by rotations
• Foliar diseases • Root rots
INTEREST IN PULSE CROPS
• Pea
• Lentil
• Chickpea
• Faba bean
• Dry bean
• Soybean
Source: Dr. Y Gan
N FIXATION
Western Canada
lbs N / acre
Alfalfa 100 - 250
Faba Bean 80 - 160
Pea 50 - 150
Soybean 40 - 140
Lentil 30 - 120
Chickpea 20 - 100
Dry Bean 5 - 70
Source: Dr. J. Schoenau, U of Saskatchewan
100 lbs/acre N @ $0.38/lb = $38/acre
PULSE BENEFITS
N benefit to next crop!
• Microbial decomposition of surface residue, root, old
nodules, root exudates
• N credit of 0.5 to 1.0 lb N/ac for every bu/ac (pea)
higher yields = lower amount
• Benefit to next crop!
% N derived from fixation Source: Dr. J. Schoenau, U of Saskatchewan
PULSE BENEFITS
Non-N benefits
• Stimulate soil biological activity
• Improved soil structure = better root growth
• Improved water holding capacity and drainage
• Break in disease cycles (canola-blackleg, cereals-
fusarium)
• Again…further benefits to the next crop!!
Dr. J Schoenau “ should add $20 to $50/acre credit for pulses”
ROTATIONS
• Crop sequence
• Considerations / drivers
• Economics = Short term gains
• Mitigate risk / insurance
• Long term sustainability / reduce fallow
• Workload
• Manage disease
ECONOMICS: 3 YEAR AVERAGE
ANNUAL NET RETURNS
Preceding Crops 2009
Canola yield
2010
Barley yield
2011
Annual Net Return 2009-2011
_______________ (bu/ac) _________________ ($/acre)
Faba bean (GM) 52 (27%) 91 (14%) 31
Faba bean 41 83 103
Field pea 45 (10%) 84 (6%) 115
Lentils 45 (10%) 85 (7%) 118
Wheat 41 80 68
Canola 37 (-8%) 83 80
*Means reflect data averaged over 5 N rates and 7 western Canada locations
O’Donovan et al. 2014. Agron. J. 106:1921-1932, Khakbazan et al. 2014. Agron. J. 106:2055-2066
MANITOBA CROP INSURANCE
NORTHERN GREAT PLAINS
Padbury et al, 2002
24.7M acres
MONTANA PULSE ACREAGE
PULSE ACRES
(PEA, LENTIL, CHICKPEA, DRY BEAN, FABA BEAN, SOYBEAN)
0
2000000
4000000
6000000
8000000
10000000
12000000
14000000
2013 2014 2015 2016 2017
SK
AB
Montana
PERCENT PULSE ACRES
Location Total cropland 2017 pulse
acres %
AB 20,427,200
2,414,932 12%
SK 38,239,600
7,146,000 19%
MB 9,727,600
2,491,000 26%
Montana 9,100,000
1,799,000 20%
20% = 1 pulse crop every 5 years…..
PLANT DISEASE DEVELOPMENT
Level of host susceptibility: • Variety selection • Plant stand
architecture • Seeding date
The pathogen needs to be present and able to cause disease
Often the biggest driver of disease risk
INTEGRATED PEST MANAGEMENT
Organic agriculture
http://www.unce.unr.edu/programs/sites/ipm/
IPM is a decision making process that uses all necessary techniques to suppress pests*:
IPM
Crop rotation
Variety selection
Seed quality
Seeding date & rate
Equipment sanitation
(clubroot)
Scouting
Foliar fungicides
Residue managment
CROP ROTATION
• Break disease cycles
• Most effective to manage
diseases with:
• Narrow host range
• Soil borne or residue borne diseases
• Less effective for diseases with
long distance spore release &/or
wide host ranges
FOLIAR DISEASES
WHITE MOLD - SCLEROTINIA
• Shows up later (canopy closure)
• Environment - favoured under wet
conditions during flowering; Cool temps.
(15-24° C; 59-75 °F) during & after
flowering
• Rotation management not as effective
as wide host range
Source Dr. B. Ziesman
(Sclerotinia sclerotiorum)
ROTATIONS FOR WHITE MOLD
(SCLEROTINIA)
• Crop rotation >=3 years out of susceptible pulses or
other hosts such as canola or sunflower
• High weed populations (stinkweed, sow thistles, Canada
thistle, wild mustard, redroot pigweed, knapweeds,
dandelions and lambs quarters).
• Rotation management not as effective as wide host range
LENTILS
ANTHRACNOSE OF LENTILS
(Colletotrichum truncatum)
• 2 races: Race 0 & Race 1
• Favoured under wet conditions
• Microsclerotia on soil surface &
residue
• Rain splash spreads from soil
surface and from lesions on
plants
• Crop rotation important
• Fungicide control
Source SK Ag
ASCOCHYTA BLIGHT
(Ascochyta lentis)
• Both seed and stubble borne
• Rotation important
• Spreads from residue to plants
and from plant-to-plant mainly
by rain splash
• Fungicides effective
• Variety resistance
Source Dr. B. Ziesman
DISEASE DECISION SUPPORT
CHECKLIST: ASCOCHYTA & ANTRACNOSE
STEMPHYLIUM BLIGHT
• Tan color canopy
• Widely dispersed pathogen
and could come from
infected seed
• Warm & wet conditions
• Not considered significant in
terms of yield loss
• Fungicides ??
Source: SK Ag
GRAY MOLD - BOTRYTIS
• Develops later in the season after canopy closure
• Soil borne spread by wind (long distance movement)
• Environment - favoured under wet conditions
• Fungicide control but hard to get into canopy
• Heavy canopy can impact
• Rotations less impact
(Botrytis cinerea)
Source: SK Ag
ENVIRONMENT IMPORTANT
Year (Number of Crops)
Percentage (%) of Lentil Crops Surveyed with Disease Symptoms
Root Rot Anthrac-nose
Ascochyta Blight
Sclero-tinia
Botrytis Stemph-ylium Blight
2012 (28)
75 71 32 32 29 36
2013 (37)
65 60 30 32 27 35
2014 (18)
72 83 6 56 0 39
2015 (18)
83 78 0 11 17 50
2016 (50)
70 74 6 86 66 88
2017 (52)
54 38 6 2 0 33
PEAS
MYCOSPHAERELLA BLIGHT
(Mycosphaerella pinodes (Ascochyta pinodes))
• Most common disease of field pea
• Severe epidemics can occur under cool, wet
conditions
• Residue is source of inoculum
• Crop rotation (1 in 3 year minimum)
• Fungicides
• Variety resistance Source: SK Ag
CHICKPEA
WHY CHICKPEA?
• Good standability
• Deep rooted & good drought tolerance
• Resistance to aphanomyces
• Later maturity can spread out harvest
• Pods are quite shatter resistant
• Good marketing options
• $$0.70/lb for kabuli
• Higher risk but high rewards!
Desi
Kabuli
ASCOCHYTA IN CHICKPEA
• Major issue in chickpea production
• Yield loss severe as disease severity increases
• Symptoms visible within 4 to 6 days of infection
• Cool temps (15-25°C or 59-77°F)
• Rainfall >150mm or >6 in.)
(source: Chongo et al., 2003).
Source: adf.farmonline.org.au
ASCOCHYTA IN CHICKPEA
• Seed, soil & residue borne
• Spreads large distance by wind
• Easily spread by physical activity in the field
• Rain splash critical in spore movement and
germination/penetration of fungus
• Rotations/stubble management
• Fungicide application
Source: SK Ag
(Ascochyta rabiei / Didymella rabiei)
Source: adf.farmonline.org.au
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
CHICKPEA ACRES IN SK (1997 TO
2016)
WHY SO QUICKLY LOST CONTROL?
• Limited options for fungicides during 1998-2002
• Increased aggressiveness of disease from 1998 to 2002
• Minimum of 2 apps (up to 7) = >>selection pressure
• Disease moves large distances
• Teleomorph stages (Didymella rabiei) = >> variability in populations
• Variability + selection pressure = resistance to fungicides
Source: Chang 2007
Regina
Swift Current
WESTERN CANADA 2003/2004
• Isolates from S AB • 74% resistant isolates • cross resistance to fungicide classes in 4 isolates
• Chlorothalonil (M5) – Bravo • Macozeb (M3) – Dithane DG • Pyraclostrobin (11) – Priaxor, Headline
Source: Chang et al, 2007
15 races now
WESTERN CANADA 2004-2007
• Random fields
• Petri dish assay
• 2006/07 >>>>> 2004/05
• Resistance to Headline (pyraclostrobin(11)) >> Quadris (azoxystrobin(11))
0
10
20
30
40
50
60
70
80
90
100
2004-05 2006 2007
YEAR OF SAMPLING
PE
RC
EN
TA
GE
sensitive
intermediate
insensitive
0
20
40
60
80
100
120
Headline Quadris
FUNGICIDE TESTED
PE
RC
EN
TA
GE
sensitive
intermediate
insensitive
Source: Bruce Gossen
MONTANA 2016
• 990 isolates
• chickpea, field peas, and
lentil fields
• 11 Didymella rabiei
isolates were resistant
under petri dish
evaluations
• 5 R & 5 S were tested on
plants
Source: Owati et al, 2017
R
S
Dis
ease
Co
ntr
ol
Fungicide [ug/ml]
MONTANA
• Acres increasing • Resistance detected • Planning is going to be key
MANAGING ASCOCHYTA
1. Crop rotation – 76% reduction with 3 non-host crops (Gan 2006)
2. Variety Selection
Source: plantmanagementnetwork.org
6.1 4.5 5.0 ?? ?? ?? ??
2. Seed Quality – (0.3% max)
3. Seed Treatment - kabuli
4. Scout often
5. Disease decision support checklist
6. Apply Fungicide Early
Source: plantmanagementnetwork.org
SYSTEMIC VS PREVENTATIVE
• Timing is critical
• Preventative must go on before disease infection
(source: Shtienberg et al., 2000).
MANAGING FUNGICIDE
RESISTANCE
Can occur when selection pressure is placed on a fungal population
Risk of resistance is highest when:
• Fungicides with a single mode of action
• Pathogens that have a high degree of genetic variation within a population
• Pathogen undergoes multiple spore stages
• Fungicides are used frequently
NOT ONLY CHICKPEA….
Pea (mycosphaerella pinodes) (2011)
• 324 isolates (Northern Great Plains)
• 19 highly insensitive to pyraclostrobin
- 14 AB, 5 SK (0 fr ND, WA)
- R. Bowness
ROTATING FUNGICIDE GROUPS
Adapted from Dr. Sabine Banniza
3 7 11 44 M5
DI carboxamides strobilurins Bacillus chloronitriles
med med high low low
Fungicide Active
Headline EC pyraclostrobin
Quadris azoxystrobin
Quadris Opti azoxystrobin + chlorothalonil
Quadrix Top azoxystrobin + difenconazole
Quilt azoxystrobin + propiconazole
Evito fluoxastrobin
Aproach picoxystrobin
Stratego trifloxystrobin + prothioconazole
Proline prothioconazole
Quash metconazole
Delaro prothioconazole + trilfoxystrobin
Vertisan penthiopyrad
Bravo chlorothalonil
Aprovia Top difenoconazole + benzovindiflupyr
ProPulse fluopyram + prothioconazole
Priaxor fluxapyroxad + pyraclostrobin
Serenade Bacillus subtilis
Endura Boscalid
Chemical Group
Resistance Risk
1. Use multiple modes of action
(See FRAC code lists)
2. Use an appropriate fungicide for
the disease you have
3. Follow label rates
4. Use one application for each
mode of action/chemistry
5. Use an integrated approach
MANAGING FUNGICIDE RESISTANCE
ROOT ROT
THE ROOT ROT PATHOGENS
• Fusarium spp.
• Rhizoctonia spp.
• Pythium spp.
• Aphanomyces euteiches
True Fungi
Fungal-like organisms
Root rots are caused by a combination of different species root rot complex
Fusarium spp. and Aphanomyces euteiches are considered to be the most importance root rot causal agents
PATHOGEN(S)
Figure 1. Schematic relationship among oomycetes, land plants, animals and fungi (adapted from http://www.apsnet.org/edcenter/intropp
/pathogengroups/pages/introoomycetes.aspx).
Fusarium Rhizoctonia Ascochyta Sclerotinia Botrytis
Aphanomyces Pythium Late blight Phytophthora
ROOT ROT FIELD SYMPTOMS
APHAN0MYCES EUTEICHES
• First detected 2012
• Severe issues 2014 & 2016
• Many wet years in a row
• 2 cycles of peas/lentils during
the wet years + past history of
peas lentils = disaster!
Source: Dr. S. Chatterton, AAFC
WHOLE FIELDS AFFECTED
Photo courtesy of L. Reiter
Radisson North Battleford
Photo: S. Phelps
APHANOMYCES EUTEICHES
• Survival of oospores in the soil without a
host for up to 20 years
• Is mobile (zoospores) and can move with
the water
• Favoured by excessive moisture and
temperatures from 22 to 27oC
• Infection can occur anytime during the
season
oospore
http://cronodon.com/images/
zoospore
Source: Dr. Banniza
2010 - peas 2010 - canola
IMPACT OF ROTATION
20 years = 5 x with 1 in 4 year rotations
= 10 x with 1 in 2 year rotations
Opprotunity for pathogens to build up!!!
WATER IMPORTANT
Photo courtesy of Dr. Sabine Banniza, CDC
PEAS = LENTILS
Photo courtesy of J. Ippolito, SMA
Photo: S. Phelps
2014
2016
2017 SITUATION
2017 APHANOMYCES INCIDENCE
ROOT ROT RISK FACTORS
1. Shortened rotation (need 6-8 year break!!!!)
2. Factors that stress plants, delay germination and slow the emergence and growth of plants increase root rot risk
• Wet conditions
• Cool temperatures early in the season
• Soil compaction
• Heavy textured soils
• Nutrient deficiency
A. EUTEICHES HOST RANGE
Crop Disease reaction Oospores
Peas Susceptible Yes
Lentils Susceptible Yes
Cicer milkvetch Susceptible Yes
Dry bean Variable Few
Alfalfa Variable Yes
Chickpeas Resistant Few
Sainfoin Resistant Few
Faba bean Resistant No
Soybean Non-host No
Fenugreek Non-host No
Dr. Sabine Banniza, CDC and Dr. Syama Chatterton, AAFC
SHORTENED ROTATIONS – OTHER
ISSUES
1. Fertility – pulses are not low or no input crops!
2. Weed control - or lack there of / herbicide resistance
Nutrient Removal Rates (lbs/bu)
Nitrogen Phosphorus Potassium Sulfur
Pea 2.3 0.7 0.7 0.3
Lentil 2.0 0.6 1.1 0.2
Chickpea Na 0.36 Na Na
Canola 1.6 0.8 0.4 0.25
Wheat 1.5 0.57 0.33 0.1
KEY MESSAGES TODAY
Learn as much a you can to
make informed decisions
before you get in the field!
1. Rotations are very
important to reduce
inoculum in a field =
prevent disease
2. Other factors are also
important – IPM +
rotating fungicides
THANK YOU – QUESTIONS?
www.saskpulse.com
@SaskPulse
Sherrilyn Phelps
306-480-9767