Pest Profile: Lamb’s Quarters
TYPE
- Annual
- Broadleaf
IDENTIFICATION
The stems are erect, 24 – 35 inches high, smooth and longitudinally grooved. They are often red or light green striped. The leaves are alternate, variable in shape, 1 – 3 inches long, stalked, coarsely toothed and covered with white mealy particles, especially on the lower surface. The flowers are small and green, and they are present in the leaf axils and at the top of the stems.
PLANT GROWTH
Seed Depth: 2-3 mm is optimum for germination.
Plant / Leaf Structure: Linear cotyledons, often purple underneath. First two true leaves are opposite; the following appear alternate. True leaves are petioled with a mealy material composed of epicuticular wax on lower surfaces. At maturity a bushy appearance with clusters of green flowers. Can reach heights of 5-6 ft.
Root System: Short, stout tap root.
ENVIRONMENTAL ADAPTABILITY
Broad adaptability, thrives even under stressful environmental conditions.
- The epicuticular wax thickens under dry conditions, helping conserve water. This adaptation can reduce herbicide efficacy, as leaf wetting becomes more challenging.
- In general, it is good practice to use higher water volumes for improved wetting and coverage.
- Highly competitive to surrounding plants/crops for water and nutrients.
- Very difficult to control as the plant increases in size.
- At a height of 10 cm +, higher glyphosate rates are required for acceptable control. Most consistent control is achieved when plants are 2.5 cm tall.
CONFIRMED HERBICIDE RESISTANCE
- Group 2 - ALS Inhibitors (ON)
- Group 5 - Photosystem II Inhibitors (ON)
Note: No confirmed cases of glyphosate resistance in Canada, however differences in glyphosate tolerance have been observed in the United States.
INTEGRATED PEST MANAGEMENT
- Herbicide Strategy:
- If present, target early weed emergence with an effective pre-seed option.
- Use an effective in-crop option to manage post-emergence weeds or escapes.
- Soil Health: Promote healthy microorganisms to enhance herbicide performance.
- Water Quality: Hard water can interfere with herbicide efficacy.
- Tillage/No-Till: Either can be used as a tool dependent on the situation.
- Tillage uproots plants but may expose dormant seeds, causing a second flush.
- No-Till promotes faster germination, reducing seedbank dormancy over time.
CONTROL TIPS
- Late seeding can provide some control because the weed tends to germinate early in the season and its seedlings can be killed through soil preparation or with a burn-off herbicide prior to seeding.
- Plant to narrow rows and with higher seeding rates to increase crop competition.
- Because the plant's seeds persist in the soil, removing escapes before seed set is useful for long-term management.
REGISTERED HERBICIDES
| Application (crop) | Product | Active Ingredient | Group | Comment |
|---|---|---|---|---|
| Pre Seed *Check label for cropping restrictions* | EMPHASIS® MAX & Glyphosate | Carfentrazon, Bromoxynil & Glyphosate | 6, 9 & 14 | Control plants up to 7.5 cm. |
| INVOLVE® 50 WDG & Glyphosate | Tribenuron-methyl & Glyphosate | 2 & 9 | Involve 50 WDG & Glyphosate | |
| BROMOTRIL® & Glyphosate | Bromoxynil octanoate ester & Glyphosate | 6 & 9 | Controlled up to 8 leaf stage. | |
| PRIORITY® HL & Glyphosate | Flurasulam & Glyphosate | 2 | Controlled at the 2-4 leaf stage. | |
| Cereals | 2, 4-D Ester 700 | 2, 4-D Ester | 4 | For larger, dry, or cold weather, heavy infections: 300ml/ac |
| BADGE® | Bomoxynil & MCPA ester | 4 & 6 | ||
| BROMOTRIL® | Bromoxynil octanoate ester | 6 | Control of seedling up to 8-leaf stage. | |
| ESTEEM ALL IN® | Fluroxypyr & Clopyralid | 4 | Low rate of 15ac/case will control. | |
| FORCEFIGHTER ALL IN® | Fluroxypyr, Bromoxynil, and MCPA Ester | 4 & 6 | Control up to 8 - leaf | |
| INVOLVE® 50 WDG | Tribenuron-methyl | 2 | ||
| OUTSHINE ALL IN® | Florasulam, Fluroxypyr, & MCPA Ester | 2 & 4 | Controlled 2- 4 leaf stage | |
| MCPA ESTER 600 | MCPA Ester | 4 | ||
| PRIORITY® HL + Glyphosate | Florasulam | 2 | Controlled at the 2-4 leaf stage | |
| RUSH 24 ALL IN® | Fluroxypyr & 2, 4-D Ester | 4 | Controlled at the 2-4 leaf stage | |
| THRASHER® | Bromoxynil octanoic ester & 2, 4-D Ester | 4 & 6 | Controlled up to 8 leaf stage | |
| TOPLINE® | Florasulam & MCPA ester | 2 & 4 | Controlled at the1-4 leaf stage. | |
| Pulses | DAVAI® 80 SL | Imazamox | 2 | Cotyledon – 4 leaf |
| DAVAI® A PLUS | Imazamox & Clethodim | 1 & 2 | Cotyledon - 4 leaf | |
| DAVAI® Q PLUS | Imazamox & Quizalofop | 1 & 2 | Cotyledon – 4 leaf | |
| PYTHON® | Imazamox & Bentazon | 2 & 6 | Cotyledon -4 leaf. Offering consistent control. Python A & B will provide more consistent control. | |
| SQUADRON® | Metribuzin | 5 | Control @ 80g/ac post-emergence. Pre-seed incorporated with Treflan EC or Rival herbicide. | |
| Canola | ADAMA GLUFOSINATE 150 SL | Glufosinate | 10 |
Please read each label to determine which herbicide is appropriate for the crop affected.
Always read and follow label directions.
REFERENCES:
Bubar, C. J., Hall, L. M., & McColl, S. J. (2000). Weeds of the Prairies. Alberta Agriculture and Rural Development Information Services.
Cowbrough, M. (2017, March). Problem weed guide for Ontario crops: Volume 1. Ontario Ministry of Agriculture, Food and Rural Affairs.
Government of Manitoba. (n.d.). Lamb’s Quarters. Retrieved November 22, 2024 from https://www.gov.mb.ca/agriculture/crops/weeds/lambs-quarters.html
Hartzler, B. (n.d.). Common lambsquarters. Crops Knowledgebase. Iowa State University Extension and Outreach Retrieved November 22, 2024, from https://crops.extension.iastate.edu/encyclopedia/common-lambsquarters
Michigan State University Extension. (n.d.). Common lambsquarters (Chenopodium album). Retrieved November 22, 2024, from https://www.canr.msu.edu/resources/common-lambsquarters-chenopodium-album
Top Crop Manager. (2018, April). Solving the problem of lamb’s quarters. Retrieved November 22, 2024, from Solving the problem of lamb’s-quarters - Top Crop ManagerTop Crop Manager