Chad Lee © 2006 University of Kentucky 1 Wheat: Weeds & Insects Presentation by: Chad Lee, Grain...
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Transcript of Chad Lee © 2006 University of Kentucky 1 Wheat: Weeds & Insects Presentation by: Chad Lee, Grain...
Chad Lee © 2006 University of Kentucky 1
Wheat: Weeds & Insects
Presentation by: Chad Lee, Grain Crops Extension Specialist
University of Kentucky
Chad Lee © 2006 University of Kentucky 2
Most of the information comes from:
ID-125: A Comprehensive Guide to Wheat Management in Kentucky
Chad Lee © 2006 University of Kentucky 3
Objectives
• Weed management options• Insect management options
Chad Lee © 2006 University of Kentucky 4
Weed Management
• Burndown Herbicides (no-till)– Gramoxone
• contact, acts quickly, spray coverage critical
– Glyphosate• systemic, acts slowly, coverage less critical
Chad Lee © 2006 University of Kentucky 5
Weed Management
• Fall and Spring Applications– Buctril
• mustards, field pennycress
– Harmony Extra XP• common chickweed, curly dock, henbit,
mustards, pennycress, shepherd’s-purse, wild garlic
Chad Lee © 2006 University of Kentucky 6
Weed Management
• Fall or Spring Application• Hoelon
– annual ryegrass
• Osprey– annual ryegrass
http://forages.oregonstate.edu/
Apply one application only, prior to joint (Feekes 6)
Chad Lee © 2006 University of Kentucky 7
Weed Management
• Fall and Spring Applications– Banvel
• shepherd’s-purse, garlic• Only on tillered, established stands
– 2,4-D• mustards, pennycress, shepherd’s-purse• Only on tillered, established stands
Chad Lee © 2006 University of Kentucky 8
Weed Management
• Fall and Spring Applications– Sencor
• common chickweed, henbit, mustards, pennycress, shepherd’s-purse
• Only on wheat varieties recommended on Sencor label
Chad Lee © 2006 University of Kentucky 10
Insect ManagementOct Nov Dec Jan Feb Mar Apr May Jun
Aphids a,b
Armyworm
Fall Armywormb
Cereal Leaf Beetle
Hessian Flyb
Figure 8-1. Small Grain Insect Scouting Calendar
The red portions indicate periods of possible economic populations.a Early planting and warm fall weather increase potential for aphids and BYDV.b Wheat planted before October 15 is subject to attack by this insect.
Chad Lee © 2006 University of Kentucky 11
Insect Management: Aphids
• Transmits Barley Yellow Dwarf Virus• Scout in Fall: until temps fall below
45 ºF.• Scout in Spring: once temps rise
above 45 ºF.
Chad Lee © 2006 University of Kentucky 12
Insect Management: Aphids
• Scouting heads prior to Feekes 10.1
• Scout entire plant, esp. near soil line prior to heading.
• Count aphids per plant in 1-ft row.
• Repeat two more times across the field.
Chad Lee © 2006 University of Kentucky 13
Insect Management: Aphids
Number of aphids per foot of wheat row required to support an insecticide application for management of BYD.
Crop age (post emergence)
Aphids/Foot of Row
30 days 3
30 to 60 days 6
More than 60 days 10
http://www.uky.edu/Agriculture/PAT/recs/crop/recgrn/smgaph2.htm
Chad Lee © 2006 University of Kentucky 14
Insect Management: Aphids
• Scouting heads after Feekes 10.1• Count aphids per head in 1-ft row.• Repeat two more times across the field.
Rating Number of Aphids
0 – none none
1 – slight < 50
2 – moderate 50 – 100
3 – severe > 100
Threshold Level
Chad Lee © 2006 University of Kentucky 15
Insect Management: Aphids
http://www.uky.edu/Agriculture/PAT/recs/crop/recgrn/smgaph2.htm
2.56 to 3.84 fl oz 30 (Grain and hay)Foliar Insecticide Rate per Acre Days to Harvest
Di-Syston 8E (Disulfoton)
4 to 12 fl oz 30 (Do not graze or cut for
forage)
Lannate 90 SP (methomyl)
1/4 to 1/2 lb7 (Grain)
10 (Grazing or feeding)
Malathion 57% EC (Malathion)
1 1/2 to 2 pts 7
Mustang Max(Wheat only)
3.2 to 4.0 fl. oz. 14 (grain, forage & hay)
Penncap-M(Methyl parathion)
2 to 3 pts 15 (Harvest or grazing)
Warrior (Lambda-cyhalothrin)
2.56 to 3.84 fl oz 30 (Grain and hay)
Chad Lee © 2006 University of Kentucky 16
Insect Management: Hessian Fly
• Larvae are found between leaf sheath and stalk at base of plant.
• Scout once after first frost in fall and from early spring until June.
• Thin, stunted, chlorotic patches in the field.
• No rescue treatment.