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Iowa Control of Virus Diseases in Nursery Stocks of Cherries 



and Other Stone Fruits , To (1) maintain virus-free scion 

 orchards of cherries; (2) develop virus-free Prunus mahaleb 

 seed trees; (3) continue survey of virus contamination in 

 scion stocks of plum varieties propagated in southwest Iowa 

 nurseries; (4) establish virus-free plum variety scion orchards; 

 (5) establish orchards of virus-free plum seed trees; (6) 

 confirm seed transmission of necrotic ring spot in P. americana . 

 perhaps other plimi seed stock species; (7) learn rate of spread, 

 if any, of virus in plum nursery blocks and scion and seed 

 tree orchards; (8) learn latency and possibility of seed trans- 

 mission of necrotic ring spot virus in P. tomentosa ; and (9) 

 explore possibility of virus contamination oT finrsery stocks of 

 peaches and ornamental Prunus. 



Bot., PI. Path. 1060 (NC-IA) 



Kans. Investigations of Virus Diseases of Stone Fruits , To (l) 



develop methods by which cherry virus disease infection can be 

 recognized under Kansas conditions; (2) determine what cherry 

 viruses are pr^ent in Kansas both in cherry and other Prunus 

 species; (3) devise means for producing virus-free propagating 

 stock; and (4) develop procedure necessary for certifying 

 virus-free cherry nursery stocks. 

 Bot, 318 



Mass. Infection Cycle and Control of Peach Canker Caused by 



the Fun^s Fusicoccum Amygdali Delacroix , To develop practical 

 control measTires for Peach Canker based on a comprehensive 

 understanding of the causal organism, 

 Bot. 24 



Mich, Effect of Ring Spot and Yellows Viruses on the Anatomy 



and Pt^iology of Sour Cherry , (1) Study if nutrition can 

 overcome effect of ring spot and yellows on growth; (2) 

 study symptomatology of virus infected trees in various 



nutrients; (3) analyze levels from different treatments 

 for N,?.K. and amino acids;* (4) study anatomy of leaves and 

 other tissues infected with these viruses, 

 Bot,, PI, Path, 813 



