formed as expected. It had the poorest color and all of the apples xvere striped. 

 Some notes were made as to the quality of red color and finish of the fruit. For 

 the most part the red of Rogers and Greening v/as bright and attractive. The 

 finish of the fruit was smooth. The red of strains 45, 8, and 12 had a tendency 

 to be dull and unattractive. The finish on many apples was very rough. 



Due to the size of the crop this report must be considered as preliminary. 

 It will be interesting to see if the strains hold their sane relative position in 

 regard to amount and type of color in future years. It now appears doubtful if 

 significant differences in other factors among the strains will be foimd, but it 

 is too early to tell as yet, A few good crop years should give us the ansv/ers, 



— IT, D, I'Veeks 



D:;:GENERArivE disease of strawberries 



The so-called running-out or degenerative diseases of plants are caused by 

 specific viruses. There are five kno\-m virus diseases of strawberries of vj-hich 

 tv;o are particularly destructive, namely. Yellows and Crinkle. All auch diseases 

 of straviberries appear to be more pronounced in the far '.'Jest then in other parts 

 of the country, Yellov^s, or Xanthosis (the Greek word for Yellovrs) is the one 

 vri.th v/hich vre are concerned in the East. Its symptoms in iJarshall and certain 

 other I/Iarshall-like varieties are very pronounced and unmistalrablc, but vury faint 

 and difficult to detect in most of the so-called eastern varieties. 



As indicated in' the July 10, 1947 issue of FRUIT KOTES, J, B, Demarce at the 

 Beltsvillc, Maryland, Station has learned that the lovf vigor, unproductive condi- 

 tion of some of our eastern varieties is due to the presence of the Yellov/s virus 

 which is either partially or alraost completely masked. In Marshall, Yellov;s causes 

 a decided yellov/ing of the loaves around the margin and betv;een the larger veins, 

 as well as a crinkling, curling, and upward cupping of the leaflets, and a marked 

 divarfing of the leaf petioles and blades. In addition, there is a premature 

 reddening or fall color of the older, outer leaves, and a pronounced suppression of 

 runner fomriation. 



During the past six years, Demaree has grafted runners of suspected plants 

 representing many varieties from mid-western and eastern states onto runners of 

 healthy Karshall plants. If the suspected plants carried the Yellov:s virus, 

 typical pronounced symptoms would develop in the i.Iarshall plants. Using this 

 method of indexing plants, Demaree has been able to detect Yellows in many of the 

 varieties commonly grovm in Hevir England, In fact, samples of Hovmrd 17 and 

 Robinson plants sent to Demaree in the spring of 1948 from one of our nurseries 

 proved positive for Ycllovis this fall when grafted onto Marshall. A second lot of 

 Howard 17 from another nursery proved to be virus-free, Stravroerry Yellows is 

 likely to spread rapidly wherever the conmon strawberry aphid, Capitophorus 

 fragaefoli a.bounds. The most outstanding symptom of Yellows in varieties commonly 

 grovm here is a slight to moderate dwarfing of plants v;ith varying degrees of 

 suppression of runner formation. 



In his most recent report 'on Strav/berry Yellows, in The Plant Dis, Rptr. 

 (U,S,D,A. ) 32:10:428-432, 1948, Demaree implies that much of the unproductiveness 

 of strawberries in the East might be due to the presence of the Yelloa'/s virus, 

 that is, v;hcre grovvring conditions are othon-/iso favorable. He offers two methods 

 for remedying the virus problem: 



"Tavo methods are available for remedying, or perhaps eliminating, the strav/- 

 berry- virus-disease problem in eastern United States, First, a temporary or stop- 

 gap method for immediate adoption by extension workers consists simply in the 

 rcccanmGndntion to growers to use for sotting now fields only vig/orous plrnts malcing 



