Intensive canola and pea rotations; is it worth the risk? Stewart Brandt

Intensive canola and pea rotations;
is it worth the risk?
Stewart Brandt
Randy Kutcher
Canola and Pea Rotations
• Current recommendations are to grow
canola or pea once in a four year rotation,
which is based on disease and weed
control requirements.
• Can better disease resistance, weed
control, fungicides and improved yield
potential overcome these restrictions?
2
Canola Pea Rotations
•
•
•
•
•
•
•
Continuous canola
Continuous Pea
Canola – wheat
Pea-Wheat
Canola – wheat-pea
Canola - wheat - pea - wheat
Canola - wheat - flax – wheat [not reported]
3
Canola Pea Rotations
– Duplicate rotations with conventional OP blackleg
susceptible variety and a HT hybrid with very good
blackleg resistance.
– Plots split to accommodate fungicides on each
crop
– All phases of all rotations present each year
– Placed sclerotia at Scott to ensure sclerotinia
4
Studies located at Scott and Melfort
Major Soil Zones of the Prairie Region
Scott
Indian Head
5
Influence of rotation length on blackleg
[14 site-years at Scott and Melfort, 2000-07]
2.5
Invigor
Westar
2
Blackleg 1.5
severity
1
(0-5)
0.5
0
Cont C
C-W
C-W-P
C-W-P-W
Rotation
6
Influence of rotation on canola yield at Scott
and Melfort, 7 location year means 2000-2006
2500
InVigor
Westar
2000
1500
Kg/ha
1000
500
0
C
2
Scott
3
4
C
2
Melfort
3
4
7
Influence of rotation on canola yield;
[average for Scott and Melfort 2000-2003, dry conditions]
1600
InVigor
Westar
1400
1200
1000
Kg/ha
800
600
400
200
Cont
C-W
Rotation
C-W-P
C-W-P-W
8
Influence of rotation on canola yield
[Average for Scott and Melfort for 2004-2006, normal moisture]
2500
InVigor
Westar
2000
Kg/ha 1500
1000
500
Cont
C-W
C-W-P
Rotation
C-W-P-W
9
Influence of rotation on pea yield at Scott and
Melfort, [Average for 2000-2006]
2500
Cont P
P-W
P-C-W
P-W-C-W
2000
1500
Kg/ha
1000
500
Scott
Melfort
10
Influence of rotation on pea yield at Scott
2500
Cont-P
P-W
P-C-W
P-W-C-W
2000
Kg/ha 1500
1000
500
2000-03
2004-06
11
Influence of rotation on pea yield at Melfort
2500
Cont-P
P-W
P-C-W
P-W-C-W
2000
1500
Kg/ha
1000
500
2000-03
2004-06
12
Fungicide responses
• Responses by canola, wheat, and flax were generally small
[uneconomic] and difficult to predict.
• Pea generally responded well when yield potential was high
13
Influence of fungicides on pea yield when yield
potential was low or high
3000
2500
No Fungicide
Fungicide
2000
Kg/ha
1500
1000
500
0
Low
Yield potential
High
14
Other effects
• Canola cultivar did not affect subsequent
wheat yield except in 2005
• Occasional yield increases on pea stubble
• Differences in residual soil N have been
small/inconsistent to date.
15
Preliminary Economics – some assumptions
and costs from SAF website for 2008
• Seed; Westar @ $4.40/kg and InVigor @ $15.40/kg
• Herbicide cost from SAFRR [$67.30/ha] was lower than our
actual for Westar and higher than our actual for InVigor.
• Fertilizer costs from SAFRR were based on higher rates than
those we used.
• Grain prices were based on 10 year [1997-2006] averages for
SK ]SAF]
– Canola at $312/t [$7.10/bu]
– Pea at $160/t
[$4.35/bu]
– Wheat at $144/t [$3.90/bu]
16
Economics – costs
Rotation
Variable costs [$/ha]
Invigor
Westar
Continuous canola
374
310
Canola-wheat
336
304
Canola-wheat-pea
311
290
Canola-wheat-pea-wheat
308
292
Continuous Pea
261
Pea-Wheat
280
17
Net Return above variable costs [$/ha]
averages for Scott and Melfort
Rotation
2000-03
2004-06
InVigor
Westar
-96
-151
172
49
Canola-wheat
6
-40
216
113
Canola-wheat-pea
28
-4
190
135
Canola-wheat-pea-wheat
16
-3
188
159
Cont canola
Continuous pea
Pea-wheat
InVigor Westar
-48
8
7
103
18
Net Return above variable costs [$/ha]
averages for Scott and Melfort all years
Rotation
InVigor
Westar
Continuous Canola
38
-51
Canola-wheat
111
36
Canola-wheat-pea
109
66
Canola-wheat-pea-wheat
102
78
Continuous pea
-20
Pea-wheat
55
19
Influence of canola price on net returns in
hybrid rotations
350
300
250
200
Cont-C
C-W
C-W-P
C-W-P-W
150
100
$/ha
50
0
-50
-100
-150
209
312
415
521
Canola price $/t
20
Influence of pea price on net returns in hybrid
rotations
200
150
100
Cont-P
P-W
P-C-W
P-W-C-W
50
$/ha
0
107
160
213
267
-50
-100
Pea price $/t
-150
21
Intensive Canola Rotations
•
Growing canola more frequently increases blackleg, even with
resistant varieties.
Will intensive rotations increase risk that blackleg resistance
will break down?
Weed control is not a major constraint with HT canola.
More intensive rotations may be possible with new varieties.
•
Need better understanding of sclerotinia implications??
•
•
•
22
23
Intensive Pea Rotations
•
•
•
•
•
More intensive rotations may be feasible.
Need at least a 1 year break between pea crops.
Consider foliar fungicides when yield potential is
high.
Need better understanding of sclerotinia
implications??
Weed control is an issue.
24
Genetically modified pea in
continuous pea at Melfort
2006??
25
Thank You