340 TWENTY-FIRST REPORT. 



Alfalfa Diseases : For some years alfalfa leaf spots have been sent to the 

 laboratory for cliajjiiosis. Occasionally a report of severe yellowing is made. 

 Following the discriminative work of F. H. Jones, it has been seen that both 

 of the leaf spots of alfalfa are present in Michigan and a part of the damage 

 previously assigned to PHt'udopeziza medieuginiH is due to the attack by 

 I'urennpeziza medico (/mis. During 1918 the latter form was sent in from Van 

 liuren and Alpena Counties. Doubtless, the distribution is much greater. 



Bean Diseases: In times past bean anthracnose. bean blight and bean 

 mosiac. in the order named, have caused damage to Michigan crops. During 

 the summer of 1918 only one report of bean anthracnose was sent to the 

 college. On the other hand, bean blight was reported as doing serious damage 

 in Cass, Osceola, Huron, Midland, Van Buren, Kalamazoo. Allegan, and Isa- 

 bella-Counties. Doubtless the disease was fomid in other bean-growing coun- 

 ties doing some damage. 



Examination of 133 samples of dry beans, some picked and others 

 thresher run. showed only five which contained any anthracnose and the 

 amount here was a small fraction of a percent in every case but one and this 

 sample showed 1.4% anthracnose. Bean blight in the country was found in 

 all but 10 samples in percentages varying from o% to a small fraction of l9r. 

 The average percentage in the samples such as would be used for planting 

 was 3%. 



The significance of these figures should not be overlooked. Weather con- 

 ditions have served practically to eliminate bean anthracnose as a serious 

 bean disease in Michigan, and the two years of extremely dry weather in 

 July and August are undoubtedly responsible for this elimination. On the 

 other hand, bean blight, which formerly was not considered a serious disease, 

 has attra<'ted much attention because of tlihe striking examples of loss, not 

 only in i>i<'kage but in its attack on leaves and stems. .\s the hot suinnicrs 

 have srrveil to check antliraciiosc. so tlicy ba\t' served to angment the beau 

 blight. 



(hi lijua beans tbe disease due to I'lii/llostichi i>ho><rnliiiii was seen at East 

 Lansing as usual, and also in uardeii locations at Coldwater. Branch C<iunty. 

 It was seen as a serious leaf blighting disease. 



I'ea Diseases: Root rot of pea was reported tiouj Alger, Wayne, and 

 Muskegon Counties. The bacterial leaf spot due to liactcriiim pini reported 

 from Colorado was found in Micbigan in various gardens. This disease has 

 been noted for many years in Michigan and seems to be increasing. In the 

 summary of plant di.sease conditions for l!tlt>. this disease is mentioned as 

 common about Bust Lansing, 



Sotno Ahmkii .seed peas were obtained from a large canning concern. The 

 crop produced from this lot of ,<eed showed much lenf spot due to bacteria. 

 Th*> tiBine Keed tisMd thf best year on ground wbleli hod iipvpr produced i»«>a3 

 boforp shnwpd n^ Kindlnrly bigh perrpntngp of iUgPnsf*. By rnrpful nnrHng ppp/1 



