April, 1914.] Report on Raspberry Curl or Yellows. 



285 



that plant happens to live. According to some of the older 

 growers in Lucas county, raspberry plants twelve years old are 

 said to have produced this "curly foliage" annually for nine years. 



One of the more striking symptoms of this disease is the 

 stunted or dwarfed appearance of the plant. See fig. 1, compare 

 with fig. 5. A withering or blighting of the canes or leaves never 

 occurs in the case of this disease. There are no indications of a 

 lack of turgescence in any of the tissues of an affected plant. 



The canes are short, and when the fruiting laterals are formed 

 the plant has a compact, bushy appearance. The internodes 

 both in the canes and in the laterals are very short. We may have- 



Fig. 4. Mottled effect of the leaves of raspberry curl. 



apparently healthy and diseased canes arising from the same 

 crown. Premature flowering of the current years' growth is 

 not uncommon, terminal inflorescence being frequently present, 

 as shown in flg. 2. Diseased sprouts emerge from the soil with a 

 sickly, pale yellowish-green color, the leaflets being small and more 

 or less curled. The writer has observed such sprouts arising at a 

 distance of three feet from the parent crown. As these canes grow 

 older, the leaflets become darker green and noticeably revolutely 

 curled. See flg. 3. 



The most striking characteristic of the diseased leaflet blade^ 

 is the arching upward of the intervenal tissues, which cause the 

 vascular system to appear sunken. See fig. 3. It is this 



