Experiment Station Record, Volume 92, January-June, 1945 Page: 71
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1945]. DISEASES OF PLANTS 71
taken directly from these 180 tomatoes were cultured; only 2 yielded the fungus.
The total seed cultured represented a relatively small number of the total seed produced
by these same plants, since most of the fruits were borne on receptacles
which did not yield Verticillium in culture and, presumably, must have been healthy.
The experiments revealed no significant relation between the discoloration of the
vascular system in either the receptacle or the core; both may be discolored in the
same fruit or possibly the receptacle may show discoloration and the core none, and
vice versa. Thegreat bulk of seed produced by diseased plants germinated readily
and produced healthy plants in the culture plates. The fact that two seeds yielded
Verticillium in culture did not necessarily prove them to be infected, since in each
instance the fungus may have been confined to the funiculus; if so, the ordinary
fermentation process of preparing tomato seed for the trade would rid the seed of
the gelatinous envelope, the funiculus, and the fungus contained in it. Neither of
the two seeds germinated, which might indicate that they had been parasitized and
killed; if so, they could have constituted no factor in dissemination of the disease
when planted. Assuming the seed to have been parasitized but not killed, there is
no assurance that the fungus would live over winter and attack the young seedlings.
That the seed can transmit the disease is considered highly improbable and certainly
of no economic importance; other means of dissemination are discussed.
Observations sur quelques maladies non parasitaires des arbres dans le
Quebec '[Observations on some nonparasitic diseases of trees in Quebec],
R. POMERLEAU (Canad. Jour. Res., 22 (1944), No. 4, Sect. C, pp. 171-189, illus.
20).-The author summarizes his observations on such tree diseases as' they occur
in the Province of Quebec, including the effects of winter injury and late spring
frosts, exposure to the sun, excessive heat and dryness, and of noxious gases and
dusts-especially in mining regions. There are 27 references.
Improved cork-borer method for inoculating trees, R. B. CLAPPER. (U. S.
D. A.). (Phytopathology, 34 (1944), No. 8, pp. 761-762, illus. 1).-Instructions
are given for modifying a cork borer to reduce the number of movements for
inoculating trees by this method. The modification contains a plunger and spring
actuated by the thumb to eject the plugs.
Ripe-spot of apples (Neofabraea malicorticis), G. G. TAYLOR and R. M. BRIEN
(New Zeal. Jour. Sci and Technol., 25 (1943), No. 2, Sect. A, pp. 63-72, illus. 9).This
disease is reported to have become increasingly serious during recent years
in New Zealand; its symptoms, incidence, economic importance, and the factors
influencing its development, as well as the morphology of the causal fungus, are
considered. Comparative symptoms of ripe rot and similar types of apple rots
occurring in that country are presented in tabular form, with additional notes for
assistance in diagnosis.
A method of inoculating peach seedlings with crown gall without using punctures,
C. O. SMITH. (Calif. Citrus Expt. Sta.). (Phytopathology, 34 (1944), No.
8, pp. 764-765).-Crown galls usually arise through injuries into which the causal
bacteria are introduced or by growing the plants in infected soil. Another method
proving equally satisfactory for infecting peach seedlings was to use a suspension
secured from soaking uninjured crown galls in water overnight. In each of a
number of 5-gal. containers filled with dark-colored mountain soil (pH 8.36), 25
germinating peach pits were planted. On emergence of the seedlings some of the
containers were watered, each with 1 qt. of a suspension obtained from soaking
20 large crown galls in 20 qt. of water overnight. After a season's growth 53 percent
of the 329 trees treated with the suspension had developed galls, as against 9.6
percent of the 93 untreated trees.
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U.S. Department of Agriculture. Agricultural Research Administration. Office of Experiment Stations. Experiment Station Record, Volume 92, January-June, 1945, book, 1947; Washington D.C.. (digital.library.unt.edu/ark:/67531/metadc5064/m1/84/: accessed April 23, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.