74 HATCH EXPERIMENT STATION. [Jan. 



A Late Bust of the Blackberry (^Chryftomyxa aUiida, Kilhti). 



This rust, like that of the asparagus, has been long known 

 in Europe, but only comparatively recently ol)served in this 

 country. It was tirst brought to attention in America in 

 1886, but, while it has been not uncommon since then, it 

 has never assumed any economic importance. Very likely 

 it has been more or less confused with the spring orange 

 rust (Cseoma luminatum, Lk.), which it slightly resembles, 

 and on that account has escaped particular mention ; still, it 

 is hardly probalile that it has lieen generally prevalent. In 

 the season of 1894, however, it became decidedly abundant 

 in our plantations, and caused considerable apprehension. It 

 was also reported from other parts of the State, and threat- 

 ened to become a serious matter. In 1895 it appeared again, 

 but not so al)undantly as in the previous season ; and this 

 year its attacks have been very slight, so that there seems to 

 be no ground for fear of danger from this source at present. 



Description. — This has been called ihe fall rust, to dis- 

 tinguish it from the spring rust, which appears much earlier 

 in the season, and is entirely distinct. The latter is a well- 

 known disease to fruit growers, as it causes much damage 

 and has been the subject of many experiments and pub- 

 lished articles. It attacks both blackberries and raspberries. 

 Chrysomyxa all)ida comes on later, appearing in August and 

 continuing through the fall. It does not attack the rasp- 

 l)erry. It is one of the true rusts, having the three kinds 

 of spores, as in the asparagus rust. In this case, however, 

 it is the a?cidia and uredo spores which are most prominent. 

 These appear in small, powdery, scattered, bright orange-red 

 spots on the under side of the leaf, and are consequently not 

 as prominent as the indications of the asparagus rust. 



While the same conclusions as to the future may be drawn 

 in this case as in that of Puccinia asparagi, still, the results 

 of three years' observation on the blackberry rust indicate 

 that we have no great cause for alarm in that direction ; 

 while in the other case, having no such definite knowledge, 

 we cannot but feel somewhat apprehensive until time shall 

 show what is to be the result. 



