198 Proceed ill (/s of TrnJidiiii Aeddeiiij/ of Science. 



cNlrciiu" defoliation caused bnl tlic yoiiiin t'i'uit was dii-octly attacked by tlu> 

 luii,uus. As a result there was a heavy fall <if tlie fruit at the time of the 

 attack and the fruit eontiinuMl \(> di-dp (ilT ail tlii(Ui.uh the seasou. In an 

 unsprayed orciiard iie;ir Mooresville examined June iTi. most of the fruits 

 still remaining on the trees were affected with the larsie. red. '•V)irth- 

 mark" lesions of this disease which in most cases caused marked crack- 

 ing and malformation. At this time most of tlie affected leaves had fallen 

 and were replaced ])y new folia,tie. In the tall r.urkholder noted that hi 

 such orchards the foliage was held about two weeks longer and that only 

 ab(mt one-half the normal twig growth was made. 



In the Mooresville orchard mentioniMJ above, the varieties Elberta and 

 Big Red were much more severely affected than the Champion and Hale 

 and most of the fruit on the first two varieties had fallen prematurely. 

 The following observations on varietal suscei)tiliility were made by P.urk- 

 liolder: The Crawford was damaged more than any other variety in the 

 state and in Morgan and Montgomery counties there was a total loss of the 

 crop on this variety. The crop on the Elberta variety was cut from three 

 bushels to one peck and the variety Belle of (Jeorgia was fully as susceptible 

 as the Elberta. The Champion variety bore but lialf a crop liecause of 

 this disease. In the same localities the varieties Adudral Dewey, Carman. 

 Smock and Salway bore full crops. Smock and Salway were especially 

 resistant and showed practically no foliage infection and bore so heavily 

 that it was necessary to thin the crop one-half. Burkholder further ob- 

 served that Scalecide was not effective against curl and that a thorough 

 application of the lime sulphur dormant spray was necessary. The dis- 

 ease was destructive in an orchard where the spraying was done with a 

 spray gun on a windy day and unsprayed stri])s were left on the branches. 

 Next to leaf curl, black spot caused by Hncfci-iiini pruni was the most 

 serious peach disease and was much worse than in 1!)19. Burkholder 

 reports that this disease was severe in Vanderburg, Daviess. Orange, Greene 

 and Lawrence counties and worst in Knox and Gibson counties. Black spot 

 was so destructive on the Hale variety in one orchard near Vincennes that 

 the affected fruits were hauled out by the barrel in June. Early in July 

 it was found prevalent on foliage and fruit and to some extent on twigs 

 of the current year's growth. Yellowing of the affected leaves and de- 

 foliation were the result. Severe hail injury to the fruit occurred in the 

 region about Decker and almost every hail wound was infected with this 

 organism so that large blackened cavities occurred on a considerable per- 

 centage of the fruit. Twig invasi(.n through hail wounds was also very gen- 

 eral and Burkholder ob.served twig attack which was severe enough to 

 cause shriveling and premature dropping of the fruit. 



Burkholder further observed that in orchards containing Itoth the Elbeita 

 and Hale varieties the Hale was much more severely affected by this disease. 

 The same ol).server noted that no control of this disease was obtained in 

 orchards thoroughly sprayed with lime sulphur but that orchards. 11 to 12 

 years old. which had received several liea\y applications of barnyard 

 manure during their history, showed remarkable resistance to this disease. 

 He further noted that two to three applications of sodium nitrate to 

 orchards of the Hale variety during the current season had no apparent 

 effect upon the disease. 



