. Carnegie Institution of Washington publication. COBB S DISEASE OF SUGAR-CANE. 25 in pure culture great numbers of the same yellow organism which had been isolated from the Australian cane (fig. 17). The bacteria were present in very great numbers and usually in pure culture in the yellow bundles of these stems. The extent of this stem infection (resulting, be it remembered, from a few needle-pricks on leaf-blades several feet removed from the nodes) will be better appreciated if transcripts are inserted from notes made at the time the canes were cut. For this purpose some observations made a
. Carnegie Institution of Washington publication. COBB S DISEASE OF SUGAR-CANE. 25 in pure culture great numbers of the same yellow organism which had been isolated from the Australian cane (fig. 17). The bacteria were present in very great numbers and usually in pure culture in the yellow bundles of these stems. The extent of this stem infection (resulting, be it remembered, from a few needle-pricks on leaf-blades several feet removed from the nodes) will be better appreciated if transcripts are inserted from notes made at the time the canes were cut. For this purpose some observations made at the end of the third month will suffice. Brought in to-day (May 6, 1903) 4 sugar-cane plants, inoculated Feb. 6. They are all badly diseased. Photographs were made of No. 6 (plate 2) and of Nos. 8 and 12 together (plate 3). No. 6.—The height of this plant is about 70 inches to the curve of the top leaves. The height to the youngest leaf is 40 inches, i. e., the plant is small for its age (6 months, nearly). Both of the inoculated leaves are dead and dried, including the leaf-sheaths. Of the leaves lower down one is dead and dry and has fallen off, and three others are partly dead—that is, dead at the tips and along one margin but green in the midrib and on the other margin. Farther up, three large leaves are dead throughout, except the sheath. Four others are dead at the tips and in the case of one for 4 feet downward. The small terminal leaf is also dead at the tip. The diameter of the stem at the surface of the earth is inch. The diameter of the stem a foot from the ground is 1 inch, including the leaf- sheaths. At the base of this plant there are three young shoots which are healthy in appearance, and live buds in various stages of pushing, one of them being an inch long. Signs of disease in the shape of bacterial slime are present under the leaf-sheaths a few inches from the base of the stem, the inner surface being gummy and wet. The inter- nodes are short; the
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Keywords: ., bookauthorcarnegie, bookcentury1900, bookdecade1910, bookyear1914
