Herbicide residual

[Shearwood Forest]

I did some throw and mows this past weekend, all 3 locations were first time plots in dozer cleared locations. Planted clover, oats, and peas last weekend in April behind the clearing process and weren't touched all summer. This past weekend I revisited them. 2 of the 3 did well with good clover coverage and oats were dying back but still standing. I seeded mixes into them all but each one got a different mix prescription. I seeded and mowed to 7in and got rain that day and night. The amount of weeds encroaching from the edges got the best of me and I thought what's the harm in spraying, I won't be able to once the mixes start coming up. I know it's not great to spray right after the mowing but it will either help or do nothing it can't hurt. So I mixed cleth crop oil and butyrac and sprayed the next day once it was dry.

I thought I had read enough of the labels and that cleth and butyrac were safe like gly to spray over seed but I've since been told that they both have residual effects. Did I just nuke all that seed?

Sent from my Pixel 7 Pro using Tapatalk

 

[FarmerDan]

No residual. There’s a lot of deep discussion about germination and over the top spraying of contact herbicides but its done successfully so frequently the discussion is of little practical value.

 

[Wind Gypsy]

I'd think 2,4-db/butyrac would have residual? Might hurt your broadleaves?

 

[Shearwood Forest]

Split decision, that seems to be what the internet concluded to. Thanks for letting me ask here and not Facebook I'd prefer to not get touched by 37 individuals for making a questionable choice.

I guess I'll have to wait until next weekend and see if I have any germination at the 14 day mark on the radishes.

Sent from my Pixel 7 Pro using Tapatalk

 

[Wind Gypsy]

Split decision, that seems to be what the internet concluded to. Thanks for letting me ask here and not Facebook I'd prefer to not get touched by 37 individuals for making a questionable choice.

I guess I'll have to wait until next weekend and see if I have any germination at the 14 day mark on the radishes.

Sent from my Pixel 7 Pro using Tapatalk

@FarmerDan's input is more valuable than mine, i thought he might have missed the butyrac in your post or just knows something I don't and that's why my response was formed as a question.

Craig Harper lists butyrac residual as "about 2 weeks" in his food plot book for what that's worth.

 

[Shearwood Forest]

@FarmerDan's input is more valuable than mine, i thought he might have missed the butyrac in your post or just knows something I don't and that's why my response was formed as a question.

Craig Harper lists butyrac residual as "about 2 weeks" in his food plot book for what that's worth.

I guess I'll just have to wait and see, I saw someone else reference Craig Harper on the subject after that fact and that's what gave me the oh crap moment.

I'm doing a lot of first time methods coming from a 1 acre of clover and the occasion brassicas planting per year to doing 10-12 acres this year.

Sent from my Pixel 7 Pro using Tapatalk

 

[Bill]

You’re good to go IMO. Biggest obstacle is a newly dozed plot. They take a bit in my experience.

 

[FarmerDan]

@FarmerDan's input is more valuable than mine, i thought he might have missed the butyrac in your post or just knows something I don't and that's why my response was formed as a question.

Craig Harper lists butyrac residual as "about 2 weeks" in his food plot book for what that's worth.

Yes I probably missed it, the technical point. And some cause for concern may be valid.

There's always soil residual when a herbicide is applied. But does it have any practical importance?

It's true that the 2,4-db will have a soil residual for a short period of time. But it is a contact herbicide just like glyphosate and clethodim. Without leaf surface there can be no absorption. Herbicides that inhibit seed germination (pre-emergents) have an entirely different action.

While there is academic debate about the effects of these herbicides have on seed germination, in my estimation, it is of little practical importance. Nobody would use these as pre-emergents.

For comparison the half life of other contact herbicides we use:

2-4, db (Butryac) half life:
2,4 db has a half life of 6 to 30 days depending on soil type

Clethodim half life:
Clethodim is of low persistence in most soils with a half-life of approximately 3 days. Breakdown is mainly by aerobic processes, although photolysis may make some contribution.

Glyphosate half life:
Glyphosate's half-life (the time it takes for half of the active ingredient to degrade) is between 3 days and 19 weeks depending on water conditions. Glyphosate disperses rapidly in water so dilution occurs quickly, thus moving water will decrease concentration, but not half-life.

 

[Bowsnbucks]

Glyphosate half life:
Glyphosate's half-life (the time it takes for half of the active ingredient to degrade) is between 3 days and 19 weeks depending on water conditions. Glyphosate disperses rapidly in water so dilution occurs quickly, thus moving water will decrease concentration, but not half-life.

I nuked a section of flower bed for my wife with gly about 2 weeks ago. It had become overrun with wood sorrel. She has some new flowers (plugs) she wants planted in that bed now. IYO - is it safe to plant them - or will they croak right away??

 

[FarmerDan]

I nuked a section of flower bed for my wife with gly about 2 weeks ago. It had become overrun with wood sorrel. She has some new flowers (plugs) she wants planted in that bed now. IYO - is it safe to plant them - or will they croak right away

I didn't mean to scare anybody by providing the half-life numbers for contact herbicides. Only meant to show there's always some measurable residual - and that for the herbicide(s) in question its inconsequential - for practical purposes.

Plant away! You'll be OK...

 

[Wild Thing]

Spraying Glyphosate over seed in this demonstration definitely hampered germination, but maybe not exactly in the same manner as what you did. Nonetheless, there isn't any question that the Gly did nuke some seed when it was heavily applied directly onto the seed. Many of us have broadcasted seed and then sprayed afterwards with little to no ill-effects, however, after seeing this experiment, I have always sprayed first and broadcasted the seed after the Gly has dried. I am not as concerned about it when I drill the seed into the soil, but when it is exposed, I have to think twice about it:

Glyphosate vs Seed Germination: Results - YouTubeYouTubehttps://m.youtube.com › watch

 

[FarmerDan]

There is a contingent of farmers who will not use gly prior to or at seeding of resistant corn or soybeans. They will use a more traditional pre-plant herbicide and reserve gly applications for weed escapes post-emergent. There's reliable evidence that burndown applications of glyphosate prior to planting reduces yield.

 

[Bowsnbucks]

Here's a likely scenario and then a question .......
There's a weedy, grassy field that someone wants to turn into a clover plot with rye as a nurse crop. Spray gly to kill weeds / grasses first ........... then what?? Wait for gly to dry - THEN spread seed the same day ......... or spread seed the next day?? (Assume no one wants to lessen germination.)

 

[FarmerDan]

Here's a likely scenario and then a question .......
There's a weedy, grassy field that someone wants to turn into a clover plot with rye as a nurse crop. Spray gly to kill weeds / grasses first ........... then what?? Wait for gly to dry - THEN spread seed the same day ......... or spread seed the next day?? (Assume no one wants to lessen germination.)

I get that multiple pre-production tasks need to be completed same-day. Because of time limitations? But I was taught to spray and get away for any number of reasons. I have never ever sprayed and planted the same day.

Thru all of this and other discussions I hear guys say, “Yea but I did it and it worked!” “It” could be anything. Ok. It worked. I alway wonder, then, if “it” could have done differently for a better outcome.

Dish soap as a surfactant comes to mind…

 

[Shearwood Forest]

I wanted to follow up on my antidotal two week evidence. I'd say the residual did affect the seed or seedlings and some seeds more than others.

First, I'll qualify weather conditions. After seeding we got immediate rain day of seeding, the following day after dry off I sprayed and that was followed by 7-8 days of no rain. Once it started raining this past week it was about perfect, alternating rain, sun, rain, sun the last few days but upon observation it seemed most of my germination in both sprayed and non sprayed plots was more along the lines of 5 day growth since good rain had started and not off the 2 week since seeding and light rain.

The good news is the cleth and butyrac did fantastic at killing or knocking back the intended weeds. The spring planted clover exploded with the hair cut, fertilizer and extra space. I found plenty of new seeded clover germinating, the small amount of buckwheat I had in the one mix also popped, winter peas that the turkey didn't eat were off to the races and I found "some" radishes. At the seed rate I hit the radishes didn't have a high % germ but I had some starting. Grains didnt do well likely due to that they did germ too fast and hit the residual would be my guess.

With more rain in the way yesterday I over seeded all 3 areas but didn't go crazy in case there is seed yet to germinate from the first go, I'll be up each of the next two weeks so I can check and seed in layers rather than hammering it now. The clover base is great but in small plots won't last into November.

I will spray these plots when needed but I will likely do it 2-3 weeks before I want to add fall seed.

Rest of my updates will be in my land tour thread but for those using the search feature I want to keep the progress of these areas after spraying located here.

Sent from my Pixel 7 Pro using Tapatalk