In recent years, cleavers have become one of the most concerning weeds in Western Canada, challenging producers and agronomists all throughout the growing season.
In a weed survey conducted by Agriculture and Agri-Food Canada (AAFC) in 2014, cleavers ranked seventh for relative abundance, up considerably from 2003 when the weed ranked 14th. In the 1970s, cleavers were all the way down in the 40th position.
Cleaver plant populations can be difficult to control for several reasons:
- The weed’s seeds can stay viable in the soil for up to three years.
- Seeds can germinate later in the growing season.
- Seeds are similar in size to canola, which creates problems at harvest and can lead to dockage.
Take action
To control cleavers effectively, you need to apply the right products at the right time. Here are three things to keep in mind when considering your management strategy:
- Cleaver plants can overwinter, which makes them difficult to control in the spring. The weeds grow out of herbicide staging quickly, so it’s important to control them when they’re small.
- Increased water volumes and sprayer pressure are effective ways to penetrate the plant’s hairy leaf surface.
- Cleavers can be resistant to Group 2 and Group 4 herbicides — and some are even resistant to both — so it helps to use products with multiple modes of action.
By using proper rates and tank mixing or layering products during pre-seed and in-crop applications, you can help reduce the risk of resistance and promote herbicide efficacy.
Your local Co-op Grow Team agronomist will help you develop a crop plan that includes herbicides for effective cleavers control.
Grow Team Agronomist
Prince Albert Co-op