I’m Looking for Weeds

The spring looks it’s finally here.  With the late spring, everyone will be excited about getting into their fields as quickly as possible.  What producers need to watch for this year is to make sure that a total package is taken to the field.  The major concern that I have is that producers will forget about their spring weed control program because of the rush to get seeding.  This could lead to severe crop yield reductions if the weeds are not manage properly this spring.  There are reasons for this concern and I will try to go through with them in this article.

There will be weeds in the fields this spring.  We had warm soils last fall and we had good moisture conditions.  These two factors mean that the weeds will there in all fields.  Winter annuals germinate the fall before.   We should see lots of weeds this spring.  If the problem is left unattended, the issues related to weeds could be significant.

For fields that were sprayed before harvest, the weeds are small and will be hard to find.  It is important that a producer looks under the straw and chaff.  I have found numerous weeds in this position.  For fields that were not sprayed last fall, there is no problem finding winter annual weeds.  They are big and they will be robbing seedbed moisture and fertility early in the season.  There are weeds under the straw and chaff in these fields also.  For this reason, it is important to make sure the weeds have emerged through the chaff layer if you are going to see control with pre-seeding burnoff.

Weeds are going to be growing fast this spring.  The soil is going to warm up quickly.  There is very little frost in the ground this spring.  Warm ground means quick emergence of weeds.  I saw volunteer canola plants that had germinated on bare soil already this spring.  That means that it won’t be long before the rest of the weeds show up.

Knowing what weeds you are seeing in your fields will be important.  The herbicides used for control of dandelion and narrow-leafed hawks beard are significantly different than what is used the control of sheppard’s purse.  It is critical to know the difference between these weeds, because in spring conditions, they all look similar.  Using the wrong control product will mean problems later in the season.  Control weeds early before crop emergence for the best yields.

Spraying before seeding will give better control of winter annuals.  When the drill goes through, there are issues with weeds being covered that will grow through the thin layer of soil.  Again, these weeds will be a problem in crop because they will be too big for effective control measures to be applied in season.

Seeding needs to be done in a timely manner.  Weed control needs to be done in a timely manner.  Do them properly and you will grow more bushels.


By Dave Cubbon, P.Ag