DISEASES OF CULTIVATED PLANTS 583 



and sheaths. In 1908 the loss of yields in rye were from 25 to 60 

 per cent of the total crop. (Cal. E. S. B. 218.) 



TIMOTHY. 



Anthracnose. This occurs upon timothy and as already noted 

 on blue-grass, orchard-grass, red-top, wheat, rye, etc. The attacks 

 eo far studied, are confined to the culms and sheaths upon the lower 

 part of the stems showing small dark masses of the anthracnose fun- 

 gus as spots upon them. This shows that the timothy is liable to 

 carry over the disease between the wheat crops. 



Bacterial Blight of Head. See blue-grass. 



Rust. Some seasons this is very prevalent upon timothy re- 

 sulting in much spotting and premature drying up of the foliage. 

 This was true to a notable degree in Ohio in 1908. 



Smut. This attacks the blades of timothy and produces in- 

 teresting developments in them. As a rule the amount of smut is 

 not serious. (See smut of blue-grass.) 



OATS. 



Anthracnose. This is a new disease of oats which attacks the 

 roots and basal portions of the culms together with the lower sheaths. 

 The attack may extend even further than has yet been determined. 

 The spores of this fungus were found adhering to seed oats of the 

 crop of 1907 and the outbreak of the disease was studied in 1908. 

 It shows by the development of the characteristic dark masses or 

 acervulffi of the anthracnose fungus upon the lower joints of the 

 stem, portions of the root and leaf sheaths. 



The amount of loss resulting from it is liable to be variable 

 since it acts by general reduction of vigor and reduced filling of 

 the grain head. Treatment with formalin as for smut will certainly 

 kill the adhering spores on seed oats. 



Blade Blight. A disease similar to that earlier described as 

 bacterial disease of oats has been very serious in Ohio during the 

 seasons of 1907 and 1908. The phenomena are those of yellowing 

 and dying of older leaves associated in most cases with the presence 

 of an abundance of leaf sucking insects such as aphids, mites and 

 leaf hoppers. Recent culture and colonizing studies made at the 

 station show the disease to be due to two specific bacteria working 

 together (Bacillus avense and Pseudomonas avense}. These have 

 been isolated and described. These bacteria are carried or trans- 

 mitted by the insects or are scattered by natural agencies. In con- 

 trol work in cages the organisms caused infection through the punc- 

 tures of the aphids (green flies.) Evidently the control of this dis- 

 ease will involve thorough seed treatment together with possible field 

 checking of the insects distributed. 



Rust. In addition to the two species of rust found upon ^Yllcat 

 and to be given under that grain, there is a rust common upon oats 

 (Puccinia coronata), usually prevalent during the rainy harvest 

 weather and more or less at all times. No remedy is as yet at hand. 



Scab Fungus. This is the same species as for wheat and attacks 

 the panicles near filling time. It results in empty hulls with the 

 pink fungus. The disease also survives apparently as an internal 



