Lesser Canary Grass
Lesser canary grass is an emerging problem for the Irish tillage industry. There has been a rapid rise of confirmed canary grass on farms across the country (Figure 14). Canary grass is generally under reported due to successful control with wild oat herbicides. Populations can explode quickly on farm to the point where the weed lodges the crop and causes severe yield losses.
Figure 1. Canary Grass damage in Spring Barley
Controlling Canary Grass on your farm
- Every farm should employ a zero tolerance policy with canary grass.
- Careful observation and vigilance around bio-security will allow hand rogueing of any plants (before seed set) entering the farm thus preventing seed return and further populations.
- Where hand rogueing is not possible crop destruction before seed set will prevent seed build up. This area should be taken out of crop production for at least 4-5 years to eliminate the weed from the field/farm
Figure 2. Locations of Canary Grass Populations confirmed by Teagasc (2019-2023)
Herbicide control of canary grass to date has been reasonably good. However the correct herbicide timing in the field is often challenging due to the staggered spring germination of canary grass (ideally delay herbicide application for as long as possible to ensure full emergence of canary grass) and achieving adequate spray droplet penetration through the crop canopy.
Figure 3. Lesser Canary Grass at Harvest
Lesser Canary Grass: Facts
- It has protracted emergence patterns, with prolific seed returns and long-lived seedbank.
- Detailed information about growth habit and biology for Irish conditions is sparse.
- Predominately self-pollinating.
- On average, a single head can produce 150-200 seeds.
- Severe infections can lodge crops and make harvesting very difficult.
- Efficacy studies within the ECT project found both ACCase/ALS herbicides when applied at full recommended label rates and at GS 12-13 (2-3 leaf stage) were highly effective on populations tested.
- No ACCase/ALS herbicides (as per label) claim lesser canary grass control.
Lesser Canary Grass: Identification
- Long dense spike heads.
- Ligule is medium to long (3-8 mm) and pointed.
- Leaves rolled in shoot.
- The root tip has a distinct red sap.
More information on the identification of Lesser Canary Grass can be found below.
Figure 4. Lesser Canary Grass Identification
Below is a video highlighting the key identifying features of canary grass.