Weeds 2012: What to expect, why and what
to do about it A number of variables influence population shifts in weeds. Included
in this are environment the previous year(s), crop rotation, herbicide
rotation and tillage systems. During the fall of 2010 and the spring 2011
we were extremely wet over much of the province. These moist conditions
coupled with cooler temperatures opened up some opportunities for various
weed species. The environment changed for the summer months to a dry hot
set of conditions. We then observed the emergence of the heat loving weeds.
Additionally, the dry conditions may have lead to an increased risk of
herbicide carryover. In short we will likely see a vast variety of weeds
species in 2012. Coupled with the fact that there was often poor crop
establishment and poor crop competition in much of the province we may
also experience high weed densities in these fields. Over the past 10
or 15 years we have seen an increase in minimum tillage and this has had
an influence on the weed species present. Additionally Manitoba producers
have been tightening crop rotations which will also influence weed species
populations shifts. If agronomists understand how all of the above will
move weed populations they will be better armed for 2012.
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