324 EXPERIMENT STATION RECORD. 



BOTANY. 



Report of the botanist, G. E. Stone and E. E. Smith (Massachu- 

 setts Hatch Sta. L'pt. 1896, pp. 57-84, Jigs. 6). — The nature of plant dis- 

 eases in general is briefly stated and numerous diseases are more or less 

 fully described. 



A bacterial disease of the strawberry, which is considered to be due 

 to the action "of Micrococcus sp., is characterized by the dark-colored 

 shriveled leaves. The bacterium was isolated, and from its manner of 

 growth in gelatin it proved to be anaerobic. Inoculation experiments 

 were successfully made, and the author considers the disease probably 

 of little consequence, the plants being attacked only when the proper 

 conditions are at hand, such as favorable weather and weakened con- 

 dition of the plants. It is thought that entrance to the plant is gained 

 through the roots, and any attempt at applying fungicides would be 

 useless. 



Brief notes are given on a stem rot of the cultivated aster, micro- 

 scopic examinations of the diseased tissue of which showed a variety of 

 organisms, such as bacteria, nematodes, and various mold-like fungi. 

 The disease is to be given further investigation. 



Leaf-spot diseases of various decorative plants are mentioued, and 

 preventive treatment suggested. 



A leaf spot disease of the india rubber plant is figured and described. 

 The first indication of the disease is the appearance of small spots or 

 streaks on the leaves, which finally turn to an ashy-gray color. The 

 disease is said to be caused by Leptostromella elastica. An effect caused 

 by sunburn is superficially somewhat similar to this disease and is 

 sometimes mistaken for it. No suggestions are given for its prevention. 



Leaf-spot diseases of the date and other palms and of begonias are 

 figured and described. 



A so called black spot of the rose, due to Pilobolus crystallinus, is 

 described. The fungus is probably saprophytic, ami with proper pre- 

 cautions could be prevented from attacking plants. 



The anthracnose of cucumber (Go llet-otrichum lagenarium) is briefly 

 described, and judicious spraying with Bordeaux mixture or other 

 fungicides, together with the proper management of the crop, is recom- 

 mended for its prevention. 



A rust of asparagus, due to Puccinia asparaginic figured and described, 

 and as it only appears on the plants late in the season and is of inter- 

 mittent occurrence, there is no immediate danger to be apprehended 

 from it. However, its continued attack upon the plants will weaken 

 them, finally causing their total destruction, and on this account the 

 tops should be collected and burned in the fall. 



A late rust of the blackberry, due to Chrysomyxa a1bi<la,is described, 

 and the same precautions are recommended for its prevention as have 

 beeu giveu for the asparagus rust. This disease has been called the fall 



