156 EXPERIMENT STATION RECORD. 



kg. of oats were oertitied to. Cereals, clover, and grass seed were most commonly 

 siibmitted for examination for their purity, germination al)ility, etc. 



Weed seed as an indicator of the origin of clover and grass seed, O. Bur- 

 chard {Landw. Vers. Stat., 56 {1902), No. 4, pj)- 297-S02, pi. 1). — In continuation of 

 the opinions expressed in the author's l)Ook relating to this subject (E. S. R., 11, p. 

 1054), a further discussion is given of the value of the weed seed contained in clover 

 and grass seed as an indication of the region in which the seed was grown. The 

 author still maintains that certain common weed seed characterize the clover and 

 grass seed of different countries. Descriptions are given of a number of species of 

 weed seed which are occasionally found in clover and grass seed imported into Ger- 

 many. The species described are Apiastrum patens, found in timothy seed from 

 North America; Verbena angustifolia, Solanum caroUnense, and Cuphea lyiscosissima, in 

 North American red clover seed; Gr'mdelia squarrosa, in alfalfa seed from the United 

 States; Argemone alba, in South American alfalfa seed; and Sideritis scordioides and 

 Leontodon crispus in red clover seed from the south of France. 



Noxious weeds, T. N. Willing (Hjd. Dept. Agr. Northwest Territories, 1901, pp. 

 56-64). — A rejiort is given by the chief inspector of noxious weeds of the inspection 

 work conductetl during the past season for the enforcement of the law relative to the 

 destruction of noxious weeds. This includes inspection of farms, public lands, etc., 

 as well as elevators and mills. Attention is called to the necessity of the use of clean 

 seed in sowing to prevent the sj^read of weeds. On the whole the enforcement of the 

 law is in a fairly satisfactory condition. 



New method for combating wild radish and mustard, Heinkich {Landw. 

 Ann. Meckl. Patriot. Ver., 1900, No. 26, p)p. 201-203; abs. in Centbl. Bald. u. Par., 2. 

 Abt., S {1902), No. 23, p. 749) . — The results of experiments in which 15 to 40 per cent 

 solutions of ChiU saltpetre, ammonium sulphate, and potassium chlorid were sprayed 

 over weed-infested fields. The weeds were affected similarly as when sprayed with 

 an iron sulphate solution, while the cereals, clover, peas, vetches, lupines, and beets 

 were not injured. The cost of the application, when the fertilizing value of the 

 solution is considered, is not so great as other means that have been recommended. 



DISEASES OF PLANTS. 



Plant diseases of 1901, W. Paddock {Colorado Sta. Bid. 69, pp. 23, pis. 5).— The 

 princii)al purpose of this l>ulletin is to stimulate a greater interest in plant diseases 

 and call attention to some of the prevailing ones. Among those mentioned are apple- 

 tree root rot, ajjple-tree rosette, injury of apples from improper si^raying with 

 Bordeaux mixture, blackberry-root disease, asparagus rust, aster wilt, currant cane 

 disease, grape anthracnose, pea-root disease, plum-leaf blight, potato diseases, straw- 

 berry-leaf blight, and stinking smut of wheat. 



The apple-tree root rot was noted in various localities in the State, and is usually 

 indicated by the yellow foliage of the trees. Certain fungi ar'e constantly associated 

 with the diseased roots, and it is thought probable that they may be ultimately 

 responsible for the destruction of the tree. Investigations showed, however, that 

 much of the injury was due to overirrigation and lack of drainage of the soil. 



The apple-tree rosette is reported from a number of orchards which were inspected 

 by the author and numerous specimens secured. No parasitic organism of any kind 

 could be discovered and the conclusion is reached that the nature of the soil was 

 probably the primary cause of the disease. The orchards were planted in a soil 

 which contained an excess of marl, in some places the substance forming a solid sub- 

 stratum. During the early part of the season water is plentiful but later the supply 

 usually becomes exhausted. The soil rapidly dries out and the trees suffer from the 

 lack of moisture, consequently the growth stoics and the tissues harden. Later in tlie 



