Clearfield OSR SU tolerance aiding establishment?

Discussion in 'Cropping' started by crazy_bull, Jan 11, 2017.

  1. crazy_bull

    crazy_bull Member

    Bear with me on this, I'm no agronomist, and just thinking out loud....!

    Seeing as a lot of the blackgrassy land in the south east gets lathered in SU's. This land subsequently gets drilled with OSR using minimal disturbance methods, thus the resulting OSR crop can get stunted by the residual SU's.

    These same areas are also high CSFB pressure areas, is the stunting effect of the SU's exasperating establishment where CSFB is nailing the emerging plants?

    Would switching to Clearfield varieties that are SU tolerant help due to them not being affected by the residuals, thus growing away from the pests?

    Or should the ground be cultivated prior to drilling standard varieties??

    C B
  2. shakerator

    shakerator Member

    Very good points for a non agronomist
    crazy_bull likes this.
  3. Brisel

    Brisel Member

    I'm in my second season fo growing Clearfield variety PT229CL. The variety has limited vigour anyway but I'd say that the greater effect on establishment has been not holding the crop back with a bold pre em herbicide like Novall/Katamaran.

    As to final yield - well, Clearfield varieties were 5-10% lower than non Clearfield varieties in NIAB TAG trial plots so I'd say the SU stunting is a non event as a selling point IMHO. Perhaps the SU in Clearanda/Clesima/Cleravo stunts the crop in October or the breeders just don't have such good genetics as modern non CL varieties?

    I've direct drilled ordinary osr varieties into land treated with Atlantis in April in a dry spring so you'd think that the risk of SU residues was higher. I had a big spray miss, fortunately where there was no blackgrass or other major weed problems. I marked the area to see if there was a noticeable effect as you described in your OP. I saw no difference in establishment, growth habit or yield of the following crop where the spray miss was. That was Atlantis - other SUs like metsulfuron methyl (Ally, Jubilee) or flupyrsulfuron (Lexus) are supposed to have a greater effect.

    Our resident agronomists like @ollie989898 @Fromebridge @richard hammond @Luke Cropwalker @cricketandcrops may also have a view on this.
    CORK likes this.
  4. Fromebridge

    Fromebridge Member

    I wasn't aware Atlantis was any safer than the other SU types. I've sprayed high dose of Ally in early May for poppies and seen stunting (not fatal) in a following OSR crop, so it can happen but I admit the risk or potential damage isn't sufficient to make you sell the discs and buy a new plough.
  5. I don't think that the Clearfield varieties are tolerant of all SU chemistry just Clearanda, but I have not tried this and probably won't. I do think that big pre em doses of metazachlor based mixes can slow down OSR establishment however.
    madbrains, Timbo1080, CORK and 2 others like this.
  6. I don't grow the yellow weed I am afraid so my knowledge is limited in that regard, but I do know Atlantis is definitely not safe to OSR.

    I did not think Imazamox was technically an SU, it just has a similar mode of action, just like florasulam etc, same taste, different drink?

    I suppose the trouble with the issue of crop damage is that you won't know until much later if the yield is affected. I have seen photos of crops that have been damaged in various ways and though they were not killed, in some cases the yield loss was 100%.

    I bet the majority of herbicides have phrases regarding following crops, and if you ask the technical guys supporting the product they will all generally advise ploughing or soil disturbance to X cm prior to drilling certain other crops.

    One of the situations where I thought there might be a problem with this is with drilling grass seed into soil that has only been min-tilled after wheat etc, and despite using nearly every product you can think of at various timings I'm still not sure I've ever seen an issue I thought might be related to herbicide residues. My guess is that a lot of organic matter and other materials around, plus having a biologically active soil might degrade soil residues more rapidly, but I doubt any manufacturer would share my optimism.
    madbrains likes this.
  7. Oat

    Oat Member

    All herbicides have a recommendation on their label. Thy will either say no restriction, shallow cultivation to 5cm, or deep cultivation to 20cm.

    Different crops have different sensitivity, therefore there can be cultivation recommendations. The sensitivity also means there can be different intervals for planting a replacement crop or a succeeding crop (after normal harvest), as the herbicide amount in the soil obviously reduces and breaks down over time. The cultivation just mixes it in the soil profile, so reduces the concentration in the seeding and growing zone.
  8. T Hectares

    T Hectares Member

    My thoughts are much the same as those above after two years of DK Imperial CL...

    The clearfield gene when added does lower yield, and possibly is slightly less vigourous.

    And as said above its tolerant to Imazamox not any other SU's so it would be as vulnerable as any other variety in this respect.

    Seed dressings and big pre em mixes can slow down establishment in my experiences, so I would grow a vigorous conventional like Elgar / Charger undressed hss with N in the seedbed before rain or leave in the heap.

    I do think it would be nice to be able to buy Hybrids without seed dressings ...
    crazy_bull and Brisel like this.
  9. dontknowanything

    We don't use any OSR pre-ems now, and have not noticed a particular uplift in autumn vigour. This autumn in particular has been very slow.
    crazy_bull and Brisel like this.
  10. Work I've seen from the Yara/DeKalb/BASF 3x3 sites suggest Clearfield more tolerate in situations where high doses of spring SU applied to previous crop and therefore showed greater vigour than non Clearfield hybrids when direct or shallow till drilled.
    Fromebridge and crazy_bull like this.
  11. I agree, but simply why spend big money on a pre em when a)slugs b)pigeons c)flea beetle and less than favourable weather conditions can take the crop out 4-6weeks after drilling?
    cricketandcrops likes this.
  12. David.

    David. Member

    J11 M40
    Is there now something that does a good post-em job on poppies in conventional varieties then?
    But I do hate using pre-ems I have to say.
  13. Astrokerb, I like using it but is expensive compared to straight propizamide.
    Brisel likes this.
  14. This is the trick now. No pre em but wallop the crop with astrokerb etc later and avoid the cost of pre em or spending money until you have a crop.

    Or you get real keen with some kerb and some forefront....
  15. I have always used the theory of "See a crop then treat a crop" and this has worked for me for a long time in MOST situations,
    occasionally it has not worked but "no system is perfect" its a %age game" .
  16. Brisel

    Brisel Member

    Forefront? Doesn't that contain triclopyr? What will that do to osr?

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