- 20 - 



Ind. Studies of Etiology, Epidemiology and Chemical Control of 

 Fruit Diseases . Learn effectiveness of (1) fungicides, com- 

 binations of ftmgicides, and of additives for control of tree 

 fruit and small fruit diseases; (2) nematocides for control 

 of nematodes in small fruit and tree fruit plantings. To obtain 

 (3) information on developmental physiology of tree fruits 

 and relate changes in jAiysiology to susceptibility to rotting 

 organisms; and, (h) additional information on factors favoring 

 develojanent and spread of B. rib is and related fruit rotting 

 organisms . 



Bot., Plant Path. 953 



Maine Virus Diseases of Deciduous Tree Fruits . To (l) learn 

 extent and importance of virus diseases in apple and cherry 

 varieties grown in Maine; (2) study epidemiology of disease 

 and insect vectors involved; (3) develop an accurate method 

 of indexing deciduoios tree fruits for virus infection; and, 

 (k) devise a workable method of control. 



Bot., Plant Path. 55 (NE-llf. See Part 1?, Section c) 



Mich. Tree Fruit Virus Diseases. — Stone Frviit Virus Diseases . 

 --Pome Fruit Virus Diseases . To (1) learn virus content and 

 extent in stone fruit stock by further survey and indexing; 



(2) learn new or undiscovered viruses by indexing trees with 

 unusual symptoms; (3) learn, more acctorately, host ranges of 

 several important viruses; {k) investigate possibility of new 

 and more effective control meeisures; (5) investigate viruses 

 of root stocks and develop disease -free root stock so\irces; 

 (6) develop auad maintain disease -free sources of varieties of 

 stone fruits; (?) investigate stony-pit virus of pears; and, 

 (8) learn host range of viruses on Hyslop crabapple* 



Bot., Plant Path. 36 Coop. ARS 



Minn. Fruit Diseases. — 12. Diseases of Tree Fruits and Methods 

 of Control . To determine (1) resistance of pear varieties and 

 seedlings to fire blight; and, (2) fungi causing wood decay in 

 apples in Minnesota euad the conditions which favor the develop- 

 ment of decay. 



Plant Path,, Bot., Hort. 2206-12 



Miss. Investigation of the Diseases of Fruit Crops and Their 



Control . To (1) identify and study pathogenic orgemisms con- 

 cerned with fruit diseases in Mississippi; (2) study factors 

 concerned with early "dying-out" of peach trees within orchards; 



(3) develop effective emd simple spray program for control of 

 peach scab, bsusterial spot, and brown rot of peach; apple bitter 

 rot and blotch; and other fruit diseases as deemed feasible; 

 and, (k) explore and study other methods of practical disease 

 control among various fruit crops as deemed necessary. 



Plant Path. HL-8 



