DISEASES OF PLANTS. 49 



tion is not carried ou iu a systematic maimer. Ilecommeudatious are made for 

 tlie development of au adequate fire system. 



Annual report of the woods and forests department, 1907, A. F. Broun 

 (Rpts. FiiHiiicc, Admin., and Condition tiudun, 1907, pp. 8.i7-864). — This is a 

 progress report of forest oi)erations iu the various provinces of the Sudan, in- 

 cluding a statement of revenues and expenses for the year. Some data are given 

 ou th9 experimental rublier plantings and on planting and tapping experiments 

 with the gum {Acacia verek). The usual native method of tapping the gum 

 tree was compared with a more careful method of removing small strips of bark 

 ouly, with tapping by means of small incisions, and with the use of supposed 

 gum-producing bacilli. The native method yielded half as much again as the 

 small-strip method, while the poorest results were secured with the supposedly 

 inoculated trees. 



French system of turpentining, A. L. Brower (Oil, Paint and Drug Re- 

 porter, 15 {1909), Ao. 18, pp. 28f, 28g, figs. ^). — This is a report of a study of 

 the French system of turpentining recently made by the Forest Service of this 

 Department for the purpose of comparing the French methods with the best 

 methods in use in this country. A detailed account is given of the French prac- 

 tices. Under the best practices in this country the productive life of a tree is 

 only 4 to 6 years, whereas under the French system trees have been tapped for 

 30 years. It is not believed, however, that the French method of turpentining, 

 which reijuires greater skill, is more costly, and less productive than any of the 

 methods used iu this country, will be received favorably by the American tur- 

 pentiner. 



DISEASES OF PLANTS. 



Plant physiology and pathology. W. R. McCallum {Arizona Sta. Rpt. 1908, 

 pp. 357-361). — A report is given of investigations carried on in the department 

 of plant physiology and pathology, the principal results given being of studies on 

 the Fusarium diseases of alfalfa, melons, cucumbers, tomatoes, and other plants. 

 These diseases are among the most destructive plaut diseases iu the Territory, 

 and they are apparently due to different forms of Fusarium the relationships of 

 which have not yet been worked out. 



Brief notes are given ou damping off in seed beds, due to species of Fusarium 

 and to a species of Sclerotinia ; and on au investigation as to the cause of the 

 dying of eucalyptus trees, which was found to be due to poorly drained soil ; and 

 the effect of flooding of the soil ou the destruction of nematodes. The experi- 

 ments showed that in boxes of soil completely submerged for 10 days the nema- 

 todes were sufficiently abundant to destroy cantaloups and tomatoes subse- 

 quently grown in the boxes. 



Physiological studies on potatoes and tomatoes are reported, the potato in- 

 vestigations being a study of some of the factors involving tuber formation. It 

 was found that tubers kept in dry, light places developed sprouts of a peculiar 

 character; they are short, thick, purplish iu color, dotted toward the base with 

 root primordia, and showing many suppressed lateral shoots. Some of these 

 elongate into tuber-like structures. If such tubers are planted the central sprout 

 continues to develop and most of the already-formed tubers enlarge, and this 

 gives the potato a considerable advantage over those planted in the usual man- 

 ner. The author states that during very hot seasons tubers seldom develop, 

 while the^'e is a luxuriant growth of tops. His experiments have shown that if 

 the excessive foliage develoianent is suppressed tubers will be formed and pro- 

 duce a fair croit. The effect of chemical substances in depressing certain stages 

 of growth have been investigated and the results thus far obtained warrant 

 further investigations along that line. 



