- Location
- Pocklington, East Yorkshire
Anyone seen these symptoms before:
My s barley has patches of stunted plants in it as shown below. The biggest and worst affected patch is shown in the first pic. Smaller patches like the other pic are more common. Many, but not all, of the smaller patches have healthier plants in the centre like the pic. The patches have a distinct edge.
The pic with the coin shows roots from an affected patch and the other is from a healthy area.
The diseased roots are smaller and there is a distinct length of narrow stem between the crown roots and the seed.
Since it rained last saturday night the healthy barley has grown tremendously and the patches are, if anything, going backwards.
The worst affected field was s barley last year (with over winter cover). Barley after oilseed rape (and a cover crop) is less affected. There appears to be a correlation with soil type. Affected crops are on my lighter sandy soil. Crops on my heavier soil are ok although they were drilled about a week later than the sand.
I have some s oats on the sandy soil (after wheat and a cc) and they are ok.
I suspected that it was a ph issue initially but there is no difference between affected and healthy (both pH 6.5).
In any case the patches wouldn't be so distinct if that was the case.
In the worst field, part is drilled with C2 seed dressed with Raxil Star and the remainder is undressed home saved seed. Both are equally affected.
I also wondered if it was damage from the fungus gnat larvae that were very numerous coming out of winter.
(@RTK Farmer found the same and identified them.)
I think the crop would grow away from the damage if it were them and I cant see any sign of them now.
A brief google session has lead me to think it could be caused by Rhizoctonia. Most of the info on that is from Australia so I am not sure if it is equally applicable here.
It is characterised by root damage in sharply defined patches and second cereals (esp barley) are particularly vulnerable. It is favoured by no-till.
I will send a sample to FERA next week for testing.
I also came across a US paper from 1992 that showed a link with the timing of cc destruction (although the cc was wheat).
Pithium is another possible cause but I think Rhizoctonia is favourite
My s barley has patches of stunted plants in it as shown below. The biggest and worst affected patch is shown in the first pic. Smaller patches like the other pic are more common. Many, but not all, of the smaller patches have healthier plants in the centre like the pic. The patches have a distinct edge.
The pic with the coin shows roots from an affected patch and the other is from a healthy area.
The diseased roots are smaller and there is a distinct length of narrow stem between the crown roots and the seed.
Since it rained last saturday night the healthy barley has grown tremendously and the patches are, if anything, going backwards.
The worst affected field was s barley last year (with over winter cover). Barley after oilseed rape (and a cover crop) is less affected. There appears to be a correlation with soil type. Affected crops are on my lighter sandy soil. Crops on my heavier soil are ok although they were drilled about a week later than the sand.
I have some s oats on the sandy soil (after wheat and a cc) and they are ok.
I suspected that it was a ph issue initially but there is no difference between affected and healthy (both pH 6.5).
In any case the patches wouldn't be so distinct if that was the case.
In the worst field, part is drilled with C2 seed dressed with Raxil Star and the remainder is undressed home saved seed. Both are equally affected.
I also wondered if it was damage from the fungus gnat larvae that were very numerous coming out of winter.
(@RTK Farmer found the same and identified them.)
I think the crop would grow away from the damage if it were them and I cant see any sign of them now.
A brief google session has lead me to think it could be caused by Rhizoctonia. Most of the info on that is from Australia so I am not sure if it is equally applicable here.
It is characterised by root damage in sharply defined patches and second cereals (esp barley) are particularly vulnerable. It is favoured by no-till.
I will send a sample to FERA next week for testing.
I also came across a US paper from 1992 that showed a link with the timing of cc destruction (although the cc was wheat).
Pithium is another possible cause but I think Rhizoctonia is favourite