NOTES AND ABSTRACTS. 
223 
(1) That after-ripening processes in the potato occurred whether the tubers 
were in the ground or in ordinary storage. 
(2) Potatos planted immediately after the maturation of a crop required 
a much longer period for the germination of the buds and the appearance of the 
plants above ground than did potatos that had a rest period. 
(3) The no-rest period tubers, when planted, produced one stalked plants, 
indicating the germination and growth of one bud. 
(4) Plants grown from the no-rest period tubers had a longer growing period 
than did plants grown from the normal rest period tubers. 
(5) Most of the seed tubers of the no-rest series plants were recovered. These 
potatos had lost very little in weight. When these tubers were planted the 
second time, germination and growth of several buds ensued. The plants 
appeared above ground in about the same time as the plants of the normal rest 
period tubers. The growing period of the no-rest period plants in the second 
planting was nearly equal to that of their first planting.- — R. /. L. 
Potato, Mosaic Disease of the, and its Transmission. By E. S. Schultz and 
D. Folsom (U.S. Jour. Agr. Res. xix. No. 7, July 1920, pp. 315-337 ; 8 plates). — 
It has been previously shown^that mosaic disease of the potato is a transmissible 
disease. There may be great variation in the severity of the symptoms shown 
by the progeny of a given stock, strain or tuber. The authors show that trans- 
mission of the mosaic disease can be done by means of tubers, grafting, plant 
juice and aphides under field conditions. Infection was obtained by intervarietal 
transfer of juice. It was apparently impossible for the infected plants to recover. 
Isolation of plants by means of insect cages, as well as elimination of insects, 
have maintained stocks disease-free, indicating that control of aphides, and 
possibly of some other kinds of insects, are the most important means of 
checking the spread of the mosaic disease amongst susceptible varieties. — A . B. 
Potato Rot Diseases and Temperature Relations. By H. A. Edsom and 
M. Shapovalov (U.S. Jour. Agr. Res. xviii. No. 10, Feb. 1920, pp. 511- 
524 ; 9 figures). — Plant pathologists are well aware that certain parasitic 
organisms which seriously injure growing crops in one latitude remain harmless 
in another. It is reasonable to assume that temperature may greatly influence 
the occurrence of these parasites. It was found that a certain degree of corre- 
lation exists between the temperature relations of some potato fungi in pure 
cultures and their geographical distribution and seasonal occurrence. This 
correlation is particularly striking in wilt-producing fungi, Fusarium oxysporum 
and Verticillium albo-atrum. A temperature of 40 0 F. will hold Fusarium 
rots on tubers in check during storage, while the susceptibility of V. albo-atrum 
to high temperatures suggests the possibility of heat treatment for infected 
seed-tubers. It is suggested that temperature tests in certain cases may serve 
as a useful supplementary method for identification of fungi showing contrasting 
thermal relationships. — A. B. 
Potato Spraying, Exreriments on the Control of the Pink and Green Aphid. 
By Loren B. Smith (U.S.A. Dep. Agr., Va., Truck Exp. Stn., Bull. 29, Oct. 1919 ; 
1 fig.). — The spring crops of Potatos are usually infested with this aphis (Macro- 
siphum solanifolii Ashmead) within two or three weeks after they come through 
the soil ; the leaves curl and drop off, and a serious loss of crops is experienced. 
Nicotine sulphate and fish-oil soap are used as spraying material. Spraying 
must be thorough , and a hard, driving spray is best. A machine that will maintain 
at least 150 lb. pressure is the most economical to use. — V. G. J. 
Potato Tuber Moth, The. By J. E. Graf (U.S.A. Dep. of Agr., Bull. 427, 
Feb. 6, 191 7, pp. 1-56 ; 45 figs., with 1 map). — A full account of the life-history, 
habits, and probable source are given of Phthorimoea operculella Zell., together 
with a bibliography. 
The earliest records are in 1854 from New Zealand and Tasmania, but no 
parasites are known in those countries, whereas in America there are, at least, 
ten parasites of this moth. They are described and figured in this paper. The 
damage consists of mining leaves, petioles, stems, and tubers. 
Preventive measures are (1) good farming, (2) leaving no tubers exposed, 
and (3) harvesting and marketing tubers as rapidly as possible. If the tubers 
are infested fumigate with carbon bisulphide, 2 lb. to 1,000 cubit ft. of space 
for forty-eight hours. — G. F. W. 
Queen Bees, The Problem of Controlled Fertilisation cf. By L. V. France 
(Journ. Econ. Entom. vol. xiv. pp. 105-110 ; Feb. 1921). — The idea of con- 
trolling the making of queen bees, which, as is well known, normally takes place 
in mid-air during the nuptial flight, has long been the dream of beekeepers. 
