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N. T. The Fire Blight Disease of Pome Fruits and Its Control . 



(Cornell) 1, Influence of Soil and Cultural Conditions on Disease Develop- 

 ment, 2, The Susceptibility of Rootstocks and Tree Framework 

 to the Disease. 3» Factors Influencing Development of Infections 

 and Methods of Prevention. 

 PI. Path. 129 



N. Y. The Fire Blight Disease of Pome Fruits and Its Control.— 1 . 



(Cornell) To determine (1) if soil texture and moisture relations may 



influence disease development, independent of influence on growth 

 of trees; (2) influence of different nutrient levels and balance 

 on development of disease in trees on soils different in type 

 and moisture, and determine effect of varying soil nutrient 

 balance on disease; (3) influence of different cultural practices 

 as to cultivation, sod culture, and cover crops on disease 

 development; and (4) apply information to reduce disease develop- 

 ment in conmercial orchards. 

 Pomol., PI. Path. 129-1 



N. Y. The Fire Blight Disease of Pome Fruits and Its Control. — 2. 



(Cornell) The Susceptibility of Rootstocks and Tree Framework to the Disease . 

 To (l) develop resistant root stock and framework for pear trees 

 so that when infections occur they will not extend into all 

 branches of trees and prevent infections in roots; and (2) deter- 

 mine relative susceptibility of different rootstocks being 

 developed for apples, and search for resistant selections, studying 

 method of propagation to learn if this does influence development 

 of infection. 



Pomol., PI. Path. 129-2 



N.Y. The Fire Blight Disease of Pome Fruits and Its Control. — 3. 



(Cornell) Factors Influencing Development of Infestations and Methods of 

 Preventions To (1; determine influence of temperature and 

 humidity on initiation of infections in blossoms and develoixnent 

 of disease; (2) find better bactericides for sprays and to 

 improve timing of applications for blossom blight control; and 

 (3) prevent infections in growing shoots by control of infections 

 already occurred by application of systemic bactericides or growth 

 substances, or other means. 

 PI. Path., Pomol. 129-3 



N. Y. Virus and Virus-like Abnormalities of Pome Fruits . Learn 

 (State) (l) exact etiology of possible virus or virus-like disorders of 



pome fruits; (2) relationships of pome fruit viruses to each other 

 and to viruses affecting other deciduous tree fruits; (3) influence 

 of environ«ent on development of symptoms of virus diseases of 

 pome fruits; (A) screen commercial varieties and species of pome 

 fruits for tolerance or resistance to pome fruit viruses: (5; 

 develop rapid, inexpensive, and reliable methods for indexing for 

 viruses of pome fruits; (6) establish sources of virus-free 

 propagating materials of important pome fruit clones; provide 

 nurseries with propagating materials; (7) devise practicable 

 control measures to prevent spread of virus diseases in the 

 nursery and in the orchard. 



PI. Path., Pomol. 73 (NE-14) 



