PEACH SCAB AND ITS CONTEOL. 



25 



of one fruit, even under the most severe conditions of natural infection (PI. Ill, fig. 1). 

 Nos. 428 to 436 and 444 to 452, inoculated witii Deinatimn sp. and "svith the undeter- 

 mined fungi A and B, developing no disease upon the areas of inoculation, confirm the 

 negative results of preceding parallel experiments and may be considered as supple- 

 mentary controls. 



In this series, including 32 fiTiits, 15 scattered infections, wliich have not been dis- 

 cussed, occurred upon uninoculated areas. These evidently resulted from occasional 

 chance infections, wMch obviously can not be entirely precluded in work of tliis type. 

 Their number, however, is so small in comparison with the number of infections 

 resulting from inocidations that they are clearly negligible. Fiuthermore, the areas of 

 inoculation were so chosen with reference to the parts of the fruit subject to natiKal 

 infection that even this minimal amount of chance infection appears to have been 

 escaped, as is witnessed by the freedom from disease of all the 100 control areas. 



Table V.- 



-Summarized results from a typical friiit-inocidation experiment, Cornelia, Ga., 

 1913. 



Inoculation. 



Number of infections after stated number of days (28, ■12, 52, or 60) 

 had elapsed. 



On inoculated areas. 



On uninoculated areas. 



Total infections. 



Source and medium. 



Distilled water: 



Control 



Do 



Do 



Do 



C. carpophilum 



Do 



Do 



Undetermined fun- 

 gus^ 



Do 



Do 



Dematium sp 



Do 



Do 



Undetermined fun- 

 gusB 



Do 



Do 



Prune decoction (0.09 

 per cent): 

 Control 



Do 



Do 



Do 



C. carpophilum 



Do 



Do 



Undetermined fun- 

 gus A 



Do 



Do 



Dematium sp 



Do 



Do 



Undetermined fun- 

 gusB 



Do 



Do 



Serial 

 No. 



V/et- 



table 



surface. 



28 42 52 60 



421 

 422 

 423 

 424 

 425 

 426 

 42' 



428 



429 

 430 

 431 

 432 

 433 



434 

 435 

 436 



43 



438 

 439 

 440 

 441 

 442 

 443 



444 

 445 

 446 

 44' 

 448 

 449 



450 

 451 

 452 





 

 

 

 

 01 

 



01 

 

 

 



Wettable surface. 



Pro- 

 tected 

 surface. 



Above in- 

 oculated 

 area. 



28 42 52 60 





 

 

 



















o! 









 



25 

 010 

 0;24 











0' 















o! 







2S'42 52 60 











W 











ol 



O' 



I i 



o; 0: 



o: 



o' 











0, 3 



0' 1 



0: 







o: o; 



OjOj 



o; 1 



o; 















Below in- 

 oculated 

 area. 



28 42 52 60 





 

 

 





 

 

 

 





 

 1 











0! 































2 







Pro- 

 tected 

 surface. 



On in- 

 oculated 

 areas. 



28 42 52 60 







01 1 

 



0, o!-. 



28 42 52 60 



0, 

 Oi 

 



o; 



oi 0| 



o! 



o' o; 



o! o: 



Oi 



0! 

 01 







0' 01 



0, 

 0| 0' 



01 ol 

 01 

 

 



0.. 

 0-. 

 



0, 



0! 











O' o! 



01- 



01. 

 





 

 



18103 





 

 

 







On unin- 

 oculated 

 areas. 



28 42 52 60 



1 

 

 1 





 

 1 



o' 



o: 



0' 

 



1 











o! 2 



oj 



o'.. 



0.. 



oi 



1 



cl2 

 

 



(d) 



(6) 



(d) 

 (d) 



m 



a Considered as supplementary controls, 

 b Considered as supplementary controls; no records 

 were made for these fruits on these days. 



-Bull. 395—17—^ 



c See discussion of results on p. 24. 



d Fruit shed before results were conclusive. 



