430 F. M. Rolfs 



days. On August 12, the leaves, the twigs, and the fruit on the spraj^ed 

 trees were free from disease. Tlie fruit was of excellent color and quality, 

 but there was sixty-one per cent less fruit on these trees than on the checks. 

 The leaves on the checks were badly shot-holed and about ten per cent of 

 them had fallen. The twigs also contained many blackened cankers. 

 Sixty-three per cent of the fruit was infected. 



In the same yesn', twenty-nine eight-years-old Elberta peach trees were 

 spraj^^ecl seven times with lime-sulfur. Eleven trees were used as checks. 

 The fu'st application was made with the standard 15-15-50 formula on March 

 12, just before the buds opened. The other six applications were made 

 with self -boiled lime-sulfur, 12-8-50 formula, after the leaves had opened; 

 the first of these was made on April 21, and the others followed at intervals 

 of from twelve to fifteen da^^s. On August 12 the foliage on the sprayed 

 trees was more or less dotted with diseased spots. The twigs also showed 

 a few black cankers. Fifty-two per cent of the fruit contained many small 

 bacterial wounds, but otherwise it was in good condition (Fig. 64). The 

 yield was reduced twentj^ per cent. On the check trees the fohage was 

 badh^ injured and ten per cent of the leaves had fallen. The twigs also 

 showed many cankers. Sixty- three per cent of the fruit was diseased 

 and cracked, its market value being considerably reduced. 



In 1909, twenty-tv/o nine-years-old Elberta peach trees were sprayed 

 fom' times with peach bordeaux mixture, 2-9-50 formula. Twelve trees 

 were used as checks. In 1908 curculio pmictures made it difl&cult to 

 determine the exact extent of injur}^ due to the attack of this organism, 

 and therefore in all the spraying experiments in 1909 arsenate of lead vras 

 added to the mixture used in the first tv\'0 applications. The poison was 

 added at the rate of two pounds to fifty gallons of the spray mixture. 

 The first application was made about seven days after the petals had fallen, 

 and the three others followed at intervals of four weeks. On August 8, 

 as far as could be observed, the leaves, the twigs, and the fruit were free 

 from disease. The foliage on the check trees was badly injured, and fifteen 

 per cent of the leaves had fallen. The twigs contained many black can- 

 kers. vSixtj^-five per cent of the fruit was injured, and most of this was 

 worthless. 



In 1909, twenty-four nine-j^ears-old Elberta peach trees were sprayed 

 four times with self-l^oiled lime-sulfur, 12-8-50 formula. Arsenate of lead 

 was added to the first two applications at the rate of two pounds of the 



