Thank you Klaus, we had similar estimations made by "experts" by flag-list damage after outbreak of Pantoea sp. on wheat last year. They gave losses about 5 centners per ha (10% of yield) with 50% flag-leaf necrosis.

Klaus,

It looks like joke, but I see very often forecasts based on unrelated experience, just by "expert opinion". In some cases it is close to truth. But, for bacteria, there are limited expermental data (the paper of 1987 is a rare case).

Last spring, we have seen in many regions a root rot & leaf spots during 2-3 weeks after snow melting, associated with P. sp & P. syringae infection, and severe leaf blight at flag-leaf stage with dense population of Pantoea sp. that happens after P. syringae (as described by Pasichnyk LA, Hvozdiak RI, Khodos SF. [Interaction of Pantoea agglomerans with the agent of basal bacteriosis of wheat]. Mikrobiol Z. 2005 Jan-Feb;67(1):32-40. Ukrainian. PubMed PMID: 15765881.. The 10% losses were forecasted based on similar value for fungal diseases, but plants were actually dry after flag-leaf death that is very unusual for fungal diseases. So, I expected higher loss. Again, a significant part of damage from bacteria happens without clear symptoms of disease. At temperatures below 22-25oC, symptoms caused by X. translucens can appear only at the end of vegetation, but symptoms from Psudomonas, in opposite, are clear at low temperatures.

At 2010 David Boehm (Syngenta) wrote "Understanding Bacterial Leaf Disease in Wheat" at http://www.smallgrains.org/ springwh/ February2010/ Bact/ Bact.html, describing losses from bacterial diseases in Montana, again, by "farmers opinion" . Actually, the last big outbreak of basal glume rot occured at 1967-1974 has happened at the same time in North Caucasian region of USSR and in N.&S. Dakota, Montana, etc. in USA. Fortunatelly, US farmers learned well the lession, and use now resistant cultivars.

We have an evidence of increasing infection of Pseudomonas syringae in seeds with rate from 0.1% at 2000-2004 to 3% (1-10%) at 2008-13.

I think that accumulation of seed infection was caused by shift to new fungicides for seed treament, specific, environment-friendly, but without significant antibacterial activity, unlike old toxic Tiram.

The specific Russian problem is that chemical bactericides (if there is any) are not permitted by the State regulator (not included in the approved list), so Companies are not interested in sales, and prefere to say that bacterial pathogens (and viruses) are not important.