GLADIOLUS

Evening Post, Volume CXV, Issue 109, 11 May 1933, Page 18

GLADIOLUS

DISEASE AND PREVENTION

Referring to a recent article in the gardening columns of "The Evening Post," dealing with "Gladiolus, Disease and Prevention," Mr. H. W. Lawton, 8.A., F.L.S., senior instructor in agriculture to the Wellington Education Board, points out that this information had been culled from numerous notes issued by himself for the use of Wellington teachers. "It may interest the public," he writes,/"to know how much careful study is necessary in connection with the study of plant diseases. "In the case of the gladiolus, two diseases are known, Bacterium marginatuin and Bacterium gummisudans. It was necessary to ascertain, witli certainty, which was present in Wellington. This necessitates the preparation of numerous sterile culture media, such as: Agar.agar, potato agar, Poptonized meat extract, glycerine jelly, etc. Portions of the diseased extracts are introduced into the medium, and incubated for varying periods. The disease may be cultured by means of "Pours,". "Stabs," or "Slants." Different bacteria grow on different media, while some liquify gelatin, and other do not. "The srtructurc and shape of the bacterial colonies on the several media, have to be studied from several standpoints. The compounded information from these two sources has to be checked up with past records. This seemed to show that the Wellington disease was Bacterium marginatum. But, to make certain, it was necessary to inject some of the. "culture" into a conn free from disease. As this injection produced the disease in a short time, it was considered that the matter was proved." ■ .