cover crops for pest management and weed suppression - hartzler
TRANSCRIPT
![Page 1: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/1.jpg)
Weed Suppression
with Cover Crops
Bob Hartzler
Meaghan Anderson
Department of Agronomy
![Page 2: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/2.jpg)
2012 SARE Cover Crop Survey
Desired cover crop benefits
• Soil compaction 58%
• Soil erosion 56%
• Nitrogen scavenging 41%
• Weed control 40%
• Increase crop yields 36%
• Nitrogen source 36%
![Page 3: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/3.jpg)
Cover crops and
weed management
• Mechanisms
– Physical barrier
– Allelopathy
– Enhanced seed predation
– Soil health
• Requirements
– Sufficient biomass
– Uniform distribution
![Page 4: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/4.jpg)
Weed suppression experiments
• Cereal rye
– Mid-September and mid-October planting
– Seeding rates: 0.5 to 5 bu/A
– Terminated first week of May
• Waterhemp and common lambsquarter
seeded in fall after cover crop planting
![Page 5: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/5.jpg)
October 7, 2013 (9 DBLP)
![Page 6: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/6.jpg)
Rye at termination
May 5, 2014
![Page 7: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/7.jpg)
Effect of rye planting date
and seeding rate on biomass
0 1000 2000 3000 4000
Oct14
Sept12
5
2.5
1.2
0.5
a
a
a
a
b
b
Bu/acre
Anderson. ISU. 2014.
Rye terminated on May 5.Feeke’s Stage 8-9 (flag leaf)
![Page 8: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/8.jpg)
0
2
4
6
8
10
12
Control Oct Sept0
2
4
6
8
10
12
Control Oct Sept
Effect of rye planting date on
LQ and WH emergence
Lambsquarter Waterhemp
Rye planting date
% e
me
rgen
ce
Anderson. ISU. 2014.
![Page 9: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/9.jpg)
0
200
400
600
800
0
200
400
600
800
Effect of rye cover crop on
waterhemp emergence patterns
Control Sept. Planting
Late
July
Early
July
Late
Jun
e
Early
June
Late
May
Early
May
Late
April
Anderson. ISU. 2014.
Late
July
Early
July
Late
Jun
e
Early
June
Late
May
Late
April
No
. wat
erh
emp
/ sq
m
Early
May
Time to 50% emergence delayedtwo weeks by rye
![Page 10: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/10.jpg)
CC biomass vs weed suppression
0 1800 3600 5400 7100 8900 10700 12500 14300
Cover crop biomass (lb/A)
Webster et al. 2013. Crop Protection
% w
eed
co
ntr
ol
(6 w
eeks
aft
er p
lan
tin
g)
Rye levels observed inour research
![Page 11: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/11.jpg)
Rye biomass accumulation
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Rye
dry
wt
(lb
/A)
Kaspar. USDA/ARS. Ames, IAFeyereisen et al. MN. Trans. ASABE.
Approximately 170 lbs/day after initiation of stem elongation.
![Page 12: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/12.jpg)
Weed suppression by cover cropsMoberly, MO. 2013.
0
20
40
60
80
100
120
Winter annuals Summer annuals
Hairy vetch
Tillage radish
Annual ryegrass
Cereal rye
Wheat
Kevin Bradley, Univ. Missouri.
![Page 13: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/13.jpg)
Terminating cover crops
• Herbicide
– Rates, coverage
• Mechanical
– Timing: anthesis
– Mowing• Enhances breakdown
• Uneven distribution
– Crimper• Direction of operation
![Page 14: Cover Crops for Pest Management and Weed Suppression - Hartzler](https://reader034.vdocument.in/reader034/viewer/2022042701/55a6f2371a28ab6d5e8b480f/html5/thumbnails/14.jpg)
Summary
• Mulch effect primarily responsible for
weed suppression
– Large amount of biomass required
– Planting date critical
• Uniform establishment and distribution of
residue