246 EXPERIMENT STATION RECORD. [Vol.41 



the fungus flora was destroyed. It is believed tliat tliis method can be made 

 practical for the control of scab and other seed-borne diseases of grain. 



Presoaking' as a means of preventing seed injury due to disinfectants and 

 of increasing germicidal efficiency, H. Braun (Science, n. ser., ^.9 (1919), No. 

 1273, pp. oJ/Jf, 543). — In the cour.se of investigations of the bacterial black chaff 

 disease of wheat, the author discovered a means of disinfecting without injur- 

 ing the seed. This is accomplished by allowing the seed to absorb water for a 

 definite period in advance of treatment. The wheat, after screening and removal 

 of sliriveled grains, is soaked for 10 minutes in water, drained, and kept moist 

 for 6 hours, after which it is soaked for 10 minutes in formalin (1 : 400), drained, 

 covere<l for 6 hours, dried overnight, and planted. If copper sulphate is used, the 

 presoaked seed are thoroughly wetted in the 1 : 80 solution for 10 minutes, 

 drained, and kept moist for 20 minutes, after which they are plunged for a 

 moment in milk of lime, dried overnight, and planted. The effect of this method 

 of seed treatment is said to be twofold — first, seed injury is prevented by dilu- 

 tion of the disinfectant as it enters the presoaked tissues of the seed, and, sec- 

 ond, the ethciency of the disinfectant on the pathogene is increased. 



The black chaff of wheat, E. F. Smith, L. R. Jones, and C. S. Reddy (Science, 

 n. ser., 50 (1919), No. 1280, p. 48).— As a result of a study of black chaff of 

 wheat, the authors were struck with the resemblance of the organism causing 

 this disease to that which is responsible for the bacterial blight of barley which 

 has been named Bacierium, transluceus (E. S. R., 38, p 548). Cross inoculations 

 of the barley organism on wheat either proved it noninfectious or resulted in 

 the production of small, nontypical lesions. On the other hand, inoculation 

 experiments with the wheat organism showed that it was practically as pa- 

 thogehic on barley as it is on wheat Some minor cultural differences were 

 observed, and it is believed that the wheat organism should be distinguished 

 from that on barley. For the present the name B. transliicens undulosum is 

 given it. 



This organism, which causes the black chaff disease of wheat, is said to pro- 

 duce yellow or translucent stripes on the leaves, water-soaked or black stripes 

 on the culms, and longitudinal, more or less sunken, dark stripes or spots on the 

 glumes. The organism also attacks the kernels, especially at the base, causing 

 them to be shrunken or honeycombed. Where the kernels are not directly 

 attacked, their surface is liable to be affected from the diseased glumes. When 

 the disease appears early and is severe, dwarfed heads are said lo result. In- 

 fections have been obtained repeatedly on wheat leaves and glumes, and the 

 disease is considered to be transmitted to the young seedlings through the wheat 

 kernels. 



The black chaff of wheat is known to occur in all the wheat States of the 

 Middle West. 



Formaldehyde v. corrosive sublimate in treating cabbage seed (Ioii-a Sta. 

 h'l)t. 1918, p. 21). — On account of unsatisfactory results in irealing cabbage 

 seed with formaldehyde, a test has been made comparing formaldehyde and 

 corrosive sublinuite. It is reportwl that a solution consisting of 1 gm. corro.sive 

 sublimate in 1 qt. water has been found to do little injury to the seed and at the 

 same tim(,' to kill the disease-producing organisms on the seed. 



Black spot of onion sets, F. L. Stevens and E. Y. True (Illinois Sta. Bui. 

 220 (1919), pp. 501-5S2, fifis. i.9).— Serious losses in storage are reported to have 

 occurred in onions, particularly in onion sets and especially in the white varie- 

 ties. Examinations were made of oniims and onion sets, and it was found that 

 the white varieties were affected to the extent of 60 to 80 per cent by the dis- 

 ease formerly described under the name Vermicularia circinam. Three types 



