DISEASES OF PLANTS. 143 



are given of the following- Aveeds, together with notes on their distri- 

 bution: Black mustard (Brassica nigra), English charlock (Brassica 

 sinapistrum), white mustard (Brassica alba), large pepper grass (Lepi- 

 ilium virginicum), small pepper grass (Lepidium apetalum), false flax 

 (Camelina sativa), shepherd's purse (Capsella bursa-pastoris), hedge 

 mustard (Sisymbrium officinale), tumbling mustard (Sisymbrium altissi- 

 mum), horse radish (Nasturtium armoracia), and winter cress (Barbarea 

 vulgaris). A number of these are illustrated. 



The mustards are disseminated chiefly with small grain seed and 

 screenings. Some of them often escape from cultivation. The author 

 estimates the number of seed produced by single plants of a number 

 of these weeds. Tables are quoted from other authors showing the 

 comparative vitality of seeds of mustards and other plants. 



The following methods of extermination are recommended: For 

 annuals, pulling up the young plants from fields, cutting the young 

 plants on vacant lots, practicing judicious methods of rotation, plow- 

 ing early in the fall, and harrowing frequently afterwards. In the case 

 of biennials, the leafy plant of the first season must be killed by culti- 

 vation. The horse radish, the only perennial considered, is very diffi- 

 cult to eradicate. Plowing the land, harrowing, and picking up the 

 roots, repeating the operation in a week, and after that keeping the 

 young plants cut down with a hoe was found fairly successful in dry 

 seasons. 



A note is given on proposed legislation for the suppression of mus- 

 tards. 



Three troublesome -weeds, F. L. Harvey (llaine Sta. Bui. 32, pp. 8, figs. 3). — 

 This consists of illustrated notes on the orange hawkweed (Hieracium atirantiaciim), 

 wild carrot (Daucus carota), and buffalo bur (Solatium rostratum), with the habits of 

 the plants and precautious for their prevention. 



Rules and apparatus for seed testing ( U. S. Dept. Agr., Office of Experiment Sta- 

 tions Circ. 34, pp. 9, figs. 2). — This gives the report of the committee appointed by 

 the Association of American Agricultural Colleges and Experiment Stations at its 

 meeting in November, 1896, "to devise and adopt a standard form of seed-testing 

 apparatus and method of procedure for use in all American stations,'' together with 

 an illustrated description of a standard seed-germinating chamber, and blank forms 

 for record, sampling, and report. 



Dodder in alfalfa (Agl. Jour. Cape Colony, 10 (1897), No. 11, pp. 619, 620).— It is 

 recommended to cut the alfalfa from the spots where the dodder occurs and cover 

 them with 6 in. of manure, treading it down well. This kills the dodder and leaves 

 the alfalfa to grow up through the manure. An application of a solution of 1 lb. 

 of suljihate of iron per gallon kills the dodder without injuring the alfalfa. 



DISEASES OF PLANTS. 



Studies upon the smut of wheat, oats, and barley, with a resume" 

 of treatment experiments conducted during the past three years, 

 H. L. Bolley (North Dakota Sta. Bui. 27, pp. 109-164, Jigs. 13).— The 

 author gives a report of extended observations on the life history of 

 stinking smut of wheat (Tilletia levis). These investigations show that 

 4513— No. 2 4 



