- Ik - 



Oreg. Diseases of Small Frylts. — 1, Strawberry Viruses « To (l) 



determine possible importance of highly resistant varieties 

 such as Rockhill, as natural reservoirs of inoculum for 

 susceptible varieties; (2) determine factors influencing the 

 expression or masking of virus symptoms; (3) determine response 

 of strawberry species ( Fragaria bracteata, F. ovalis . F. cuneifolia, 

 F. chiloensis, F, vesca ), and other closely related native 

 herbaceous plants ( Potentilla gracilis . P. anserina . P. glandules a . 

 Horkelia congesta . Geum mscrophyllumt etc.) when inoculated with 

 strawberry viruses, and their importance as reservoirs of inoculum; 

 also certain other species ( Rosa nu tkana . Rubus leucodermis , 

 R. laciniatus, R, idaeus, R, s£»» Medics go sativa . etc.): Ck) 

 determine possibility of inactivation of strawberry viruses by 

 means of chemical therapeutics; (5) test varieties and selections 

 carrying different components of virus complex for vigor, 

 productiveness and longevity under field conditions; (6) develop 

 and maintain virus-free foundation stocks of chief comnercial 

 varieties and imreleased USDA hybrids under vector proof conditions; 

 and (7) determine possibility of preventing or slowing spreao of 

 strawberry viruses by controlling insect vector, Capitophorus 

 fragaefolii (ck. ). 



Bot.& PI. Path., Ent. 137-1 Coop. ARS 



Oreg. Diseases of Small Fruits, — 3» Raspberry Yellow Rust . To 



determine (1) how to control rust; (2) the economic value of 

 yellow rust control; and (3) whether a spray program for control 

 of yellow rust can be based on the developmental stage of the 

 causal fungus rather than the development stage of the host plant. 

 Bot. & PI. Path. 137-3 



Pa. Breeding Improved Varieties of Raspberries . To (l) breed 



improved raspberries having resistance to freezing, disease, 

 and insects, and desirable horticultural characteristics; (2) 

 deteradne types and extent of virus infection; (3) identify 

 and study insect vectors causing transmission of viruses; and 

 (a) study inheritance of certain characteristics. 

 Hort., Zool., Ent., Bot. 1094 (NE-9) 



Tenn. A Comparative Study of Inheritance in the Cultivated 



Raspberry With Reference to Certain Diseases and to Fruiting 

 Habits . To determine the comparative values as parents of 

 certain cultivated red raspberries when crossed with Van Fleet 

 or other hardy types in the production of disease resistant, 

 productive, and desirable hybrids. 

 Hort. 118 



