62 a EXPERIMENT STATION. [Jan. 



DEPARTMENT OF BOTANY. 



A. V. OSMUN. 



The botanical work of the experiment station during 1915 has 

 been along lines previously reported. Diagnosis of plant dis- 

 eases, seed separation, germination and purity tests, and result- 

 ant correspondence have required much time and attention. 

 While the responsibility for these activities has alwa3^s been 

 assumed by the experiment station, it would seem that the 

 time must soon come when such work will be done by members 

 of the staff paid from extension service funds. Service work of 

 this sort does not legitimately belong to men employed for 

 research, and it seriously inhibits progress on their research 

 projects. 



Several diseases not previously noted as occurring in the State 

 were reported. These are mosaic of sweet pea; ringspot of 

 cauliflower, caused by Mycosphoerella hrassicoecola (Duby) Lin- 

 dau;^ and a leaf spot of digitalis, caused by an undetermined 

 species of colletotrichum. 



Silvery scurf of potatoes, first reported from this State in 

 1914, appeared in several new localities during the last year. 



The summer of 1915 w^as notable for its large number of 

 cloudy days and heavy rainfall, and the relative humidity dur- 

 ing July and August was considerably above normal. Such 

 conditions are ideal for the development of fungous diseases of 

 plants, and crop losses from this source were exceedingly heavy. 

 The number of complaints and entailed correspondence were 

 proportionately larger than usual. 



Among the diseases most frequently reported were late blight 

 of potato, rhizoctinia stem rot of potato, downy mildew of cu- 

 cumber and melon, anthracnose of cucumber, sooty blotch of 



1 Osmun, A. Vincent, and Anderson, P. J. Ringspot of Cauliflower. In Phytopathology, 

 6, p. 260, 1915. 



