Broom's Barn Applied Crop Sciences
11 August 2009 : Samples received so far - 87
Early season : Early samples were the usual mixture - soil pest damage, herbicide damage, poor establishment due to dry conditions. However, something that many samples had in common was the poor state of the roots - these were brown, and often covered in fungi, such as Rhizoctonia. Presumably this was due to slow growth in the dry weather. Whereas plants would normally romp away from such problems, they grew slowly which made them vulnerable.
Mid season : Even in July many samples came in with brown unhealthy roots, despite most areas receiving good downpours in mid-June. Unfortunately, another dry spell followed these downpours and, on many soils, roots found it difficult to grow again. As in recent years, the Clinic has continued to receive several samples with beet cyst nematode, from June onwards.
In June we received a classic sample of Rhizoctonia damage (Barney Patch) from Norfolk. The Clinic hasn't received a really striking case for two or three years, largely due to the closure of Allscott factory from whose area many samples came (although in that part of the country the problem was called 'Shifnal Stunt'). Rhizoctonia is normally a secondary problem, but on some light soils it can become very aggressive, creeping all over the tap root as well as the lateral roots (where it is normally found).
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| Rhizoctonia damage (Barney Patch) |
Discoloured foliage is proving a problem for many advisers and growers, with identification of the cause of yellowing a particular headache. As well as the usual suspects, magnesium deficiency and virus yellows, the clinic has received samples of foliage yellowed by boron deficiency, downy mildew, capsid damage and what looks like premature senescence due to drought stress, cyst nematode etc. One case investigated was a crop with bronzing / necrosis on outer leaves and this was thought to be potassium deficiency
For further information about the Broom's Barn Plant Clinic E-mail alan.thornhill@bbsrc.ac.uk and for information about the activities of Broom's Barn please contact brooms.barn@bbsrc.ac.uk
