Why early weed control matters for lentils and peas

November 18, 2020

Weed management is essential in pulses, because the truth is, they just aren’t competitive crops.

Pulse crops are highly susceptible to yield losses of 20-40% as a result of weed competition. Thin crop canopies in lentils and peas mean weeds take early advantage of these non-competitive crops. In fact, it takes peas two weeks longer than other crops to develop a viable canopy to decrease light penetration for weed growth, positioning this crop at a serious disadvantage for battling weeds.

Yield losses add up

Agriculture and Agri-Food Canada research* demonstrates the importance of early weed removal in peas. Pulse yields can be reduced up to 25% by delaying weed control until four weeks after emergence**. With an average crop yield of 32 bu/ac, the production loss could equate to over $50/acre (based on yellow peas at $7.50/bu).

Annual weed removal (weeks) after pea crop emergence

Yield loss
1 0%
2 7%
3 12%
4 26%

Dealing with resistant weeds

Early weed management is essential to reduce yield loss, but with limited herbicide options, the next challenge is dealing with the increasing problem of resistant weeds in lentils and peas.

Problem resistant weeds in Western Canada for lentils and peas include Group 2-resistant kochia, wild mustard, cleavers and Group 1- and Group 2- resistant wild oats.

The problem with kochia in pulses

One of the biggest weed threats to pulse crops is kochia. It is resistant to multiple herbicides; early spring germination (in soil temperatures as low as 2C) and low seed dormancy (overwinters well) means early control of kochia is essential. Pre-seed burndown or pre-emergent soil active herbicides are your best bet to stay ahead of kochia in the spring.

Get ahead with GoldWing®, Valtera™ EZ and Fierce®

Nufarm has a few unique herbicide options that can help pea and lentil growers get ahead of weed problems. If little fall work was done, and there’s winter-annuals or new weeds emerging in spring, GoldWing is an excellent pre-seed burndown partner with glyphosate.

Pre-emergent soil active herbicides like Valtera EZ and Fierce are recommended for extended weed control (up to eight weeks) because they take care of flushing weeds. This helps get lentil and pea crops established so that they can compete not only with weeds, but for soil moisture, nutrients and sunlight.

A clean start is imperative to maximizing yields in pulse crops. If you are looking for different herbicide options to manage weeds, give us a call at 1-800-868-5444. You can also reach out to your local Nufarm Territory Manager.

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Sources:

*https://albertapulse.com/pea-weed-control/

** https://www.manitobapulse.ca/production/field-pea-production/pest-management/