The calls have already started. Weed control is less than perfect. That shouldn't surprise anyone since it's been that kind of year. Purdue University weed control specialists are fielding questions about weeds, many of them that have been enemies for a long time. The specialists include Bill Johnson, Glenn Nice and Tom Jordan.
Heavy rains delayed planting, and preemergence herbicides have been under pressure, the specialists note. Many companies have been pushing their own blends of preemergence herbicides this year for Roundup Ready corn. The idea was to get good weed control early and prevent early season yield loss to weeds, then let glyphosate take over if necessary. Of course, this only works on hybrids that are resistant to glyphosate over the top.
This year's dirty dozen, actually dirty baker's dozen, that the trio expect to see, are based partly upon the fact that the grass control component of prememrge programs typically gets rained away first.
So here is what you've been waiting for. Drumroll, please
1) Morningglories, an oldie but goody if you're a weed lover, a pain in the side if you're combining the field. They can literally take over.
2) Waterhemp- Coming in from the west, this weed is expected to show up in several areas of Indiana this year.
3) Burcucumber- It may start out growing on a fence row, but it can grow long vines and be a bear to control once it gets a head start in the field.
4) Fall panicum- This grass used to cause trouble later in the year in the days before better grass control herbicides were developed.
5) Common ragweed- Believe it or not, it's listed just above its giant cousin. There are great products against these weeds- it's just that this spring has not been conducive to controlling them.
6) Giant ragweed- Old-timers call it horseweed, but others call marestail horseweed. Just know it can get as big as a small sapling if it gets out of control. Stay on it early.
7) Yellow nutsedge- Another grass, look for it growing in the lowest, wettest parts of the field. It usually doesn't get that tall, but it can still suck away yield, depending upon how the rest of the season turns out.
8) Shattercane- This annual can be taken out easily with glyphosate or with several postemergence grass herbicides in soybeans. If it's in conventional corn, it's a bear.
9) Crabgrass- Usually thought of as a lawn grass where strands are thin, it can also show up in fields.
10) Lambsquarters- Famous for going from little shavers to too big to spray overnight, expect these guys to be there. Only a few can cause significant yield impact.
11) Smartweeds- Pennsylvania is the most common variety. The leaves develop a reddish cast. Patches of smartweed are often found in wetter areas.
12) Nightshades- Black nightshade has been quiet for a while, but might not be this year. If they aren't controlled, they can produce berries that clog up the combine and turn soybeans purple.
13) Barnyardgrass- Here's another grass. Notice that the foxtails are absent, but there are still plenty of old stand-by weeds you may have to contend with.