MICHIGAN ACADEMY OF SCIENCE. 123 



Till-: :Mi('iri(!AX im.axt diskash sfkvf.y fok lou. 



BY G. II. COONS. 



For a iiiiinbei" of years the Depai'tment of Botanj^ at M. A. C. 

 has been ooiKluctinji' a ])lant disease surveT in coojieratioii Avitli 

 the F. S. Depavlineiit of AiiiiciiKin-e. This work which is carried 

 oil throughout the Fnited States, has for its object the collection 

 of data as to distribution, severity, and control measures for various 

 plant diseases. In .Michigan the basis for a comprehensive survey 

 is being laid. The collections of fungi at Ann Arbor have been 

 listed in reports of this academy by Pollock and Kautfinan. and 

 this work has been carried on to the present time by Dr. Kauffman. 

 The collections at M. A. C. exclusive of the Basisiomycetes- have 

 beeen listed by me in the 1012 Academy Eeport in a provisional 

 host index, which includes the fungous collections at Ann Arbor 

 as well. In this host index a literature list is given which iuclvides 

 the luycological and pathological work done in the state or with 

 ^Michigan material. A comi)reliensive account of Michigan plant 

 diseases is to be prepared in the near future to serve as a summary 

 of the j)resent status (»!' our knowledge of Michigan pathogenes. 

 This jtapei- merely atteuipts to record a few of the plant diseases 

 either new to the state or of particular importance which were met 

 with last year. 



I'OT.VTO IIISKASES. 



The Curl If Dwarf Disease. In 11)14 in a popular exy)eriment 

 station bulletin (00) on potato diseases, Dr. Hessey discussed 

 dangerous potato diseases at that time rare or unknown for ]iliclii 

 gan. Since then an extensive survey and especially the work of 

 the group of scientists which under the auspices of the F. S. De- 

 partment of Agriculture visited fields in the state, have given 

 further information on Furly Dwarf and Leaf Boll wliich we did 

 not have at the time of Dr. Bessey's summary. 



Th that bulletin. Curly Dwarf was described as reported from but 

 one locality. A grower in :>rontcalin County had noted occasional 

 dwarfed ])lants which yielded only small worthless tubers. He 

 saved the tubers tVom some of these hills and found that when 

 these were planted the progeny was of the same worthless nature. 



