Rademacher (BASF 2000), Kane&Smiley (1983) reported on root and shoot growth inhibition and potential links to disease expression with azole materials.
GRDC also warn that certain growth retarding fungicide seed treatments can cause “silly seedling syndrome” and coleoptile growth can be further compromised when followed with dinitroaniline herbicides (pendimethalin, trifluralin etc).
Cautions about using fungicide seed dressings
Read and follow directions on fungicide labels carefully.
In some situations, certain fungicide seed dressings may reduce coleoptile length, which could lead to ‘silly seedling syndrome’ (leaves grow under soil surface but don’t emerge), particularly if short coleoptile varieties or deep sowing are used. Check chemical labels for this information. Coleoptile shortening may also result from use of dinotroaniline herbicides (trifluralin, pendimethalin, oryzalin). Take care where coleoptile-shortening seed dressings are used together with these herbicides, particularly where it is difficult to obtain good depth control of herbicide incorporation and seed placement, such as in sandy soils.
The above, alongside environmental, cultivation etc can have implications for crop establishment and one advantage of the endophytes in TIROS is the ability to reduce these impacts and ensure the crop prioritises resource to where it is most needed, often this is into root growth ahead of shoot growth.
We saw this this earlier, thanks to a keen eyed Green Crop Farmer, who sent in these pics.
Upon establishment, it became clear the impact of the endophytes in TIROS – in this case they had prioritised root growth ahead of shoot growth.
So a key point when examining the effects of seed treatments is to look at the root system in terms of root quantity, architecture, length and the overall crop establishment.
Needless to say with other products e.g. Vibrance Duo and also more biologically active soils – no / min till the reverse is the case with crops emerging very rapidly. So I think now we have to revisit how we assess seed treatments and examine their benefits, but like we have always said look below ground to make the best judgement.
Unium have been looking at this for several years – not in sufficient detail to answer all the questions prompted above but in a high overview level to look at the impact of “mother crop inputs” on the daughter crop.
Here is an over view of the results so far:
Last year we screened 12 metabolites (UBS009 being the best one). This year we have rationalised to 5 for more detailed evaluation along with 13 new seed treatment molecules. We look forward to sharing the data as soon as we have it.
So I think this really is an exciting step forward in looking at the genetics, the nutrition, soil biological and applied biology to maximise not only the current crop but the following seed crop.
As we move into a new era with greater adoption of biologicals, biostimulants, signalling molecules, soil regeneration, carbon fixation etc etc, we have to start thinking more consequentially as these systems tend to be more affected than conventional chemistry. Integration of biologicals into conventional cultural practices requires attention to be given to optimise their performance – what else do I need to consider when I make this decision? rather than previously it being a binary decision – do I need to apply this to control that……… it’s a more complex world but a very exciting and challenging one.
We look forward to sharing more information along the journey.