Herbicide question...

weekender21

Well-Known Member
While driving today my mind drifted off to fall food plot work that's yet to be completed on the other side of the planet. I've been thinking a lot about which plots I might spray and which ones I might just try to mow. Then a thought entered my mind that I don't really have the answer for.

When you spray a plot in the fall at the time of planting, aren't the weeds you're typically targeting summer annuals? If that's the case, then isn't that a waste of herbicide and time? I'll be planting in a few weeks and although the growing season isn't completely over, I'm assuming all the pesky summer annual "weeds" have produced seed for next year and won't be doing much more growing this fall. Soooo, if I spread seed then mow (throw and mow) without spraying, should I expect less of a food plot compared to if I did spray?

What say you?

In the unlikely event my thought is accurate, wouldn't you get more from spraying in early summer prior to a planting of BW for example? Then use the throw and mow process in the fall without a herbicide treatment?
 
There's a whole lot of answer to your question! I can only offer a line or two.....

It's simply a case of competition. If all the weeds truly are summer annuals AND their life cycle is nearly complete, then how much competition can those mature plants provide to a new seeding? If there are perennials - like grasses - in the plot, you have a decision to make. How much competition will they provide?

Weed CONTROL doesn't necessarily mean weed KILL. There are many methods for control. Spraying, sure. But mechanical means can be just as effective. Does that include mowing? Sure, if it reduces competition AND will allow the seed to get into the soil. Throw first and mow after? I've never been a big fan, but for many here, it works.

As an aside, the cheapness of glyphosate has made a lot of people spray happy. I'm one of them!

Another good method of weed control is maintaining soil fertility. Keep pH and nutrients at levels where your desired crop can out compete weeds.
 
I plow in the spring, run disk over it and leave it. Mid July I herbicide with round up and 2,4,D. After die down I fit and plant fall food plots.

BUT, I have had the same thouhgts, kill the summer weeds that have started and then disk or till and bring up new weed seed that sprout and grow with my fall planting. duh! Wouldn't I be smarter to treat clover plots in the spring and not worry about weeds in the fall?
 
I did spray a plot for T&M brassica few wks ago but that is first Ive done for Several years. Anymore I spread seed, sometimes mow, but mostly jst walk away. Most the summer grasses and weeds are in their dying stages anyway.
I’m not anti chemical but I dont use them very often and find very little diff on performance of perennial or annual plots. And the soil organisms so needed for health of soil seem much more prevalent without the chem use.


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This is a great question! Each spring I spray our clover plots with clethodim, cool season grasses seem to be the most competitive to the young clover and seems to be not as controlled by winter rye. So, should I even bother to spray to prep in the next week or so? Our other tough competitor to our clover is Johnson grass, I’m not sure spraying it now will help with next year at this time. I’ve always sprayed 4 weeks before planting, so I don’t have a control group.
 
I like to mow summer weeds/annuals before seed maturity in an effort to make things better next yr., and to help reduce spraying. Grasses usually take a couple of mowings before they give up on bolting, but they are early successional plants doing their job to help the soil so I don't necessarily want to kill them. Once they run out of energy for reproducing (end of summer) and other species start their journey it's time to plant my fall/winter plots. If I time it (spraying) right I can reduce competition for what I plant but keep the soil induced with living roots and microbes at all times... and reduce adding to the seed bank an amount that would be prohibitive the following yr.
 
I would l like to mow more often Cat, but it’s just not feasible on some of the properties. Weeds really don’t bother me that much, deer don’t mind them and quail love them. I usually replant clover every third year anyway, so I guess it’s not that big of a deal.
 
It depends on what chemical you are spraying and what weeds you are spraying them on.
Some weeds are annuals and some are perennials and some actually kill better with a later spraying. Take Canada Thistle and Clopyralid 3 for example. It labeled to control thistle all the way up to the bud stage. I seem to get a better kill when I spray CT later.
Other chemicals like Raptor can only be sprayed once per season (as per the label) but most weeds need to be in the early stage.
One weed I have is hairy galensoga and it is a late emerger. So spraying earlier won't accomplish much. Spraying later allows earlier weeds to get too mature for Raptor.
Glyphosate is NOT effective on all weeds like mares tail or pig weed so that is yet another complication.
Weed management sucks.
 
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Your train of thought is logical, but most weeds defy logic. It depends which weeds are a problem at your property, for example most marestail rosettes start in fall plots and overwinter, making fall spraying critical for controlling this pest the next spring. When you have weeds herbicide is never a wasted effort.
 
I definitely have summer annual weeds, possibly some perineal grass but not much. The biggest culprit at the moment are blackberry and hardwood saplings. Not because they're taking over my plot, I'm taking over their plot. Many of the saplings and blackberry were spared in an effort to save top soil.
 
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A few examples. Trimmed but never sprayed. Planning to spray at the end of the month.


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Clopyralid 3 is your herbicide for woody plants. Google stinger...same active ingredient. The best part is you can plant brassicas or your cereals and then come back in and spray it over the top of your plot later in the fall. The only draw back is you wont be able to put legumes back into the plot for 10 months, according to the label. I will be doing this exact thing next weekend as i have woody plants that just won't die with a gly dose during planting. I purposely wait for the brassica rotation to take care of them.
 
Clopyralid 3 is your herbicide for woody plants. Google stinger...same active ingredient. The best part is you can plant brassicas or your cereals and then come back in and spray it over the top of your plot later in the fall. The only draw back is you wont be able to put legumes back into the plot for 10 months, according to the label. I will be doing this exact thing next weekend as i have woody plants that just won't die with a gly dose during planting. I purposely wait for the brassica rotation to take care of them.

Good to know. Thinking about gly and mowing at time of planting. Might try one of the hardwood specific options next summer by spot spraying if still needed.


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Good to know. Thinking about gly and mowing at time of planting. Might try one of the hardwood specific options next summer by spot spraying if still needed.


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Woody volunteer plant species left over from clearing land are not a big threat that needs to be dealt with right away. First of all, they aren't spreading rapidly over your entire field like grass does, second, they are held at a standstill by normal mowing and fieldwork, third, they're deer food. I wouldn't use special herbicide to get rid of them, they will eventually die off on their own because they cannot tolerate continuous farming operations. One blade of any type of grass is the biggest threat in the field, because if left untreated that one plant can take over the whole field in two years time. There are several broadleafs and sedges that rank right up there with grass, including ragweed, marestail and thistles etc.
 
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Woody volunteer plant species left over from clearing land are not a big threat that needs to be dealt with right away. First of all, they aren't spreading rapidly over your entire field like grass does, second, they are held at a standstill by normal mowing and fieldwork, third, they're deer food. I wouldn't use special herbicide to get rid of them, they will eventually die off on their own because they cannot tolerate continuous farming operations. One blade of any type of grass is the biggest threat in the field, because if left untreated that one plant can take over the whole field in two years time. There several broadleafs and sedges that rank right up there with grass, including ragweed, marestail and thistles etc.

Good point. My original plan was to mow the saplings for a few years until they surrendered.


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Well I'm reading along and will stay with Bush hog low as I can, disturb the soil a bit, plant and pack somehow. But my plots are previous pasture so not much woody stuff.
That is for fall planting. Summer planting I give up!
 
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