Abstract
A description is provided for Pseudomonas coronafaciens. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Avena sativa and very rarely Secale cereale. Also infects the following when spray inoculated without wounding: Hordeum vulgare, Triticum aestivum (Elliott, 1920), Bromus catharticus, Festuca elatior, Hordeum stenostachys, H. bulbosum, Lolium multiflorum and L. perenne (Tessi, 1949). Briza maxima, Bromus hordaceus and B. rubens are reported as slightly susceptible when artificially inoculated (Tessi, 1953). DISEASE: Halo blight of oats. Lesions usually appear on leaves, but may occur on sheaths or glumes occasionally. They are oval and light green at first and centred around the stomata, which are the points of infection. The centres become slightly depressed, one to several mm diam., greyish and dry, with a pale green to yellowish halo-like margin that often is 1 cm wide. The tissues are not water-soaked and exudate is not usualy produced. GEOGRAPHICAL DISTRIBUTION: Probably occurs in most oat-growing areas (CMI Map 356, ed. 2, 1968). An additional record not included is Argentina (Tessi, 1949). TRANSMISSION: Within the field transmission by wind and rain occurs, with infection usually taking place through stomata or wounds. It is seed borne (Elliott, 1920). Dickson (36: 259) states that insects are important in distribution, but gives no reference to support this.
Bacterial halo-blight of oats in Japan
