HORTICULTURE. 641 



hour, also at 80° C. for 1 and 2 minutes, and 70° C for 1 minute, sliowed tliat 

 neittier tlie untreated seed nor any one of tlie treated samples succeeded in 

 producing as many plants in the field as the sample produced sprouts in 

 germination tests. The highest percentage of field growth was 61.7 per cent, 

 while the average of 40 tests in the laboratory showed 77 per cent. 



Evidence is submitted controverting the contention of seedsmen that alfalfa 

 dodder does not mature seed in the Northwest. 



Work with weeds, H. L. Bolley {North Dakota Sta. Bpt. 1909, pp. 56, 57),— 

 Attempts to procure a substance destructive to quack grass and sow thistle 

 without being injurious to the soil have as yet been essentially negative. As 

 a chemical of cheap grade which would be destructive to dandelions and non- 

 injurious to grasses, stone walks, clothing, etc., calcium chlorid has been used 

 with considerable success, though not as yet recommended as a substitute for 

 iron sulphate. 



The extensive field trials with iron sulphate against dandelions previously 

 noted (E. S. R., 19, p. 56) were continued. It is concluded that this treatment 

 is quite practical on large lawois, and that the cost, using field sprayers, is less 

 than that for mowing such lawns. 



The beneficial effect of the iron sulphate in preventing diseases of blue grass 

 was again noted. 



Weeds of the farm and garden, L. H. Pammel (New York and London, 

 1911, pp. XI +281, pi. 1, figs. 174). — The author presents a partial bibliography, 

 consisting of easily accessible references, and devotes particular attention to 

 descriptions of some common weeds. He deals with many more forms from 

 eastern North America than from the Pacific coast or the Southern States, and 

 presents numerous new drawings. Special chapters are devoted to the nature 

 of the crop injury due to weeds, a classification of weeds based on duration, 

 the dispersal of weed seeds, seed testing to detect impurities, weed laws and 

 seed-control laws, weeds of special crops, poisonous and noxious weeds, migra- 

 tion, extermination, and morphology of weeds, and treatment for special weeds. 



HORTICULTURE. 



A new method of shortening the rest period of woody plants, F. Jesenko 

 (Ber. Dent. Bot. GeseU.. 29 (1911). No. .'). pp. 273-2<S//, pJ. 1; abs. in Gard. 

 Chron., 3. ser., 50 {1911), No. 1286, p. 131). — The method of forcing plants re- 

 cently experimented with by the author consists in injecting into the stems 

 dilute solutions of alcohol or of ether, and likewise of watei*. The injection 

 fluid is contained in a vessel and subjected to a pressure of about one atmos- 

 phere, side tubes connecting the vessel with the branches to be forced. Solu- 

 tions of different strengths were used. 



Tests conducted in December with the common lilac. Forsythia, and the 

 flowering plum gave negative results. In January, however, the branches of a 

 number of trees were successfully forced both with alcohol and with ether as 

 well as with the water injection. With the black locust, for example, it was 

 shown that a 5 per cent solution of alcohol, or 0.1 per cent ether solution, in- 

 jected into cut branches caused the buds to expand about 3 weeks earlier than 

 untreated branches. A number of consecutive tests with black-locust branches 

 indicate that the treatment is only effective in stimulating the buds during the 

 rest period. The failure to stimulate the buds of the above-named shrubs is 

 attributed to the fact that these shrubs had practically passed through their 

 rest period and were only awaiting favorable weather conditions, such as may 

 be obtained in the greenhouse, to start growing. 



12.544°— No. 7—11 4 



