54 EXPERIMENT ST.VriOX KEfORD, 



jjaliiig and drying of the leaf and stem and the pour condition of the head. 

 The most conspicuous lesions are found in the sheath nodes just above the 

 joints of the stem, at the region where the stem becomes the axis of the head. 

 A fungus that does not seem to be distinguishable from the rice blast Piricu- 

 laria has been found on crab grass, and it is thought probable that this host 

 plant may serve as a source of infection for rice. The results of inoculation 

 experiments and the conditions favoring the occurrence and spread of the dis- 

 ease are given. An account of preventive measures, based largely upon the 

 experiments by the South Carolina Station (E. S. It., 18, p. 244). is presented. 



Brown spot of rice grains, which is also called speck and pip, is characterized 

 by the presence of one or more discolored shrunken areas on the grains, the 

 typical spots being regularly cii'cular, about t^ in. in diameter, and bounded 

 by a dark marginal line. The interior portion of the grain under the si)ot is 

 chalky, opaque, and brittle, and the whole grain is of inferior quality. A care- 

 ful examination of diseased tissues showed the pi-esence of several kinds of 

 bacteria and fungi and also that the center of each spot contained a minute 

 de|)ression such as might be caused by the prick of a fine needle. This sug- 

 gested the possibility of hisects being the cause of the trouble, and a study 

 pointed to the fact that the primary cause of the disease is CEbalus pugnax. 

 This insect was found abundant in the rice fields, and the bacteria and fungi 

 present followed the injury caused l)y this pest. 



The green smut usually affected only a few grains in a head, causing their 

 enlargement, the fungus responsible for this trouble being UstUaginoidca rircns. 

 This disease has been known in Japan for a long time, and in Louisiana it has 

 been found on the Honduras and red rice, and less frequently on Japan rice. 

 The life history of the fungus is very poorly known, and at ])resent no definite 

 means of infection have been determined. The treatment of seed with formalin 

 or other fungicides, which have been used with success for similar diseases, it 

 is believed would prove adapted to the prevention of this disease of rice. 



The black snuit, which, so far as the author's observations liave gone, is con- 

 fined to the Honduras and red rice, is due to TUletia horrida. This may be 

 controlled by treating the seed with any of the better known methods of seed 

 treatment. 



[Fermentation and diseases of tobacco], O. Loew {Porto Rico Sta. Rpt. 

 J9fn\ mi. lt)-lS, fig. 1). — Brief notes on the method of fermenting tobacco and 

 the diseases of tobacco in Porto Rico. 



The author is of the opinion that the so-called after-fermentation of tobacco 

 proceeds much more energetically in the continuously warm climate of Porto Rico 

 than in tlie T'nited States, and that it appears unnecessary in the case of the 

 main fermentation to turn over the bulks of tobacco quite so often as in the 

 States, although a temperature of 5.5 or .56° C. should be reached in each bulk 

 the first time. 



Relative to diseases of tol)acco the opinion is advanced that the various 

 troubles observed in the T'nited States occur more or less in Porto Rico. The 

 mosaic disease and the wilt disease do not .-ippear to be general. 



Ij. DuBois reports a trouble observed with the tol)acco in a certain secitou of 

 the Aibonito district, in which the tobacco several weeks after fermentation ac- 

 quires sudi a disagreeable odor as In render it worthless. An examination of 

 some of this tobacco showed the odor 1<> be moldy or musty. The vines were 

 covered here and there with a white mass and many of the stems were so rotten 

 that they easily broke into fragments on being handled. A microscopical ex- 

 amination revealed no fungus mycelium, but numeroiis bacteria, especially 

 cocci, as well as yeast-like cells. The disease resembles pole burn. The cause 

 is still undetermined. 



