THE IRRIGATION AGE. 



827 



5, 6, 11 and 12, shows that the second application, likewise, 

 was of very little value; and since we may assume that the 

 spray applied at this time would remain efficient for at least 

 ten days, we are led to the conclusion that infestation of the 

 fruit probably did not begin much before May 10. We may 

 also reasonably conclude, from the fact that practically all of 

 the spots upon the fruit which had been sprayed four times 

 were very small, that the protective influence of the last spray 

 did not extend quite to the end of the period of infestation, 

 and this conclusion is supported by the fact that light showers 

 which would provide conditions favorable for infestation oc- 

 curred as late as June 22. 



From the single season's work, then, we may conclude 

 (1) that peach fruit spot can be controlled by spraying; (2) 

 that so far as this disease is concerned the first and second 

 applications were worthless; (3) that practically all of the 

 infestation of the fruit occurred between May 10 and June 15; 

 (4) that during that period the fruit should be protected by 

 some fungicide; (5) Bordeaux mixture (3-6-50) was the only 

 spray used upon the trees in foliage. There is some danger 

 of injuring the foliage with Bordeaux, but under the condi- 

 tions which prevailed during our experiments none whatever 

 occurred. 



Work in 1908. 



November 1, 2, 1907, the entire orchard was sprayed, 

 with the exception of one row through the center, which was 

 left as a check. All of the trees south of this row were 

 sprayed with "stock solution" lime-sulphur (sp. gr. 1.255, 

 Beaume 29.5) diluted 1 to 9 ; all north of the row were sprayed 

 with 6-6-50 Bordeaux. About one-half the leaves had fallen 

 before the applications were made. 



Notwithstanding the fact that the results of 1907 demon- 

 strate that the first and second applications were valueless, it 

 was thought best to test this conclusion by another season's 

 work, hence the plan of work for 1908 was essentially the 

 same as for 1907, except that the entire orchard was sprayed 

 and the various sprayings were so timed that the fourth oc- 

 curred June 24 instead of June 1. Provision was also made 

 for a larger number of plats for testing a somewhat greater 

 range of combinations as shown in the following table. Stock 

 solution lime-sulphur was also used upon some of the plots 

 after the trees were in foliage. 



In the table the various columns correspond to those of 

 Table I except that the one marked "Fall" shows the spray 

 which was applied November 1, 2, 1907. The dates of the 

 other applications were as follows : 



"A" represents first spray applied March 4-5 just as the 

 buds were beginning to swell. 



"B" represents second spray applied May 13. 

 '" represents third spray applied June 4. 



"D" represents fourth spray applied June 24. 



"E" represents per cent of infested fruit at picking time. 



TABLE II. SHOWING RESULTS OP SPRAYING FOR 



PEACH FRUIT SPOT IN 1908. 

 Plot Fall "A" "B" "C" "D" "E" 



1 83.8 



2 66.8 



! Boi d. - 46.6 



4 Bord. Bord. Bord. Bord 2.7 



6 Bord. Bord. Bord. Bord. Bord. 3.6 



6 Bord Bord 39.2 



30.3 

 41 

 21.5 

 8.4 

 25.6 

 41.2 

 4.1 

 21.5 

 41.4 

 78.1 

 76.3 

 36 

 30.2 

 19.6 

 15.S 

 3/9 

 17.1 

 2.5 

 50.9 

 9.7 

 8.8 

 21.7 

 50.8 

 19.4 

 34 

 64.3 

 10.7 

 10.5 

 25 



The stock solution lime-sulphur which was used in 1908 

 had a specific gravity of 1.25 (Beaume 29). For the first 

 application it was diluted 1 to 10 ; for the second, 1 to IS, and 

 for the third and fourth, 1 to 20. Bordeaux 5-6-50 was used 

 for the first spraying and 3-6-50 for the second, third and 

 fourth. 



Bordeaux again caused no injury whatever to the foliage. 

 The lime-sulphur, 1 to 18, which was used for the second 

 application, caused an almost perceptible amount of injury ; 

 but when the effect of the third application, 1 to 20, was 

 added to this the injury became quite noticeable. For this 

 reason only a comparatively few of the trees were sprayed 

 for the fourth time with lime-sulphur, but on these no further' 

 injury could be detected. 



Figs. VII. and VIII. Showing Effect of Fall Spi 

 Peach Twig Blight. 



Controlling 



In the main, the conclusions, which were drawn from the 

 results obtained in 1907, are sustained by those of 1908. Again 

 does it appear that the first applications, just as the buds are 

 swelling, is of practically no value in controlling peach fruit 

 spot. Again are we led, by the good results obtained from 

 the second and third applications, which correspond very 

 closely, in dates, to the third and fourth applications of 1907, 

 to the conclusion that the period of infestation by the fungus 

 is confined from May 10 to June 15 and that this, therefore, 

 is the critical period during which the growing fruit should 

 be thoroughly protected by spraying. However, the inference 

 that good results would follow an additional application in 

 late June was -not justified by the results. Moreover, at pick- 

 ing time, much of the fruit which received the last spraying 

 (Continued on page 833.) 



