ONE-SPEAY METHOD FOE CODLING MOTH, ETC. 



137 



THE PLUM CUBCULIO. 



The plum curculio proved to be unusually destructive in the 

 Strathmore orchard, which had not been plowed for at least two 

 years and had grown up in grass and sod. The results of the respec- 

 tive treatments in the control of this insect are shown in Table XVIII, 

 and as will be noted the percentage of fruit free from curculio injury 

 is in all cases comparatively low. Nevertheless the one-spray treat- 

 ment shows a gain of 17.08 per cent of fruit free from injury over the 

 demonstration treatment, and a gain of 30.67 per cent of fruit free 

 from injury over the unsprayed trees. The location of the trees in 

 the respective plats does not indicate a more favorable place as 

 regards liability to curculio injury for the one-spray block and the 

 notably higher benefit of the single treatment in the control of the 

 curculio on this plat is not understood. 



Table XVIII. — Injury by the plum curculio for entire season, Plats XIII, XV, and 

 XVIL Mount Jackson, Va., 1909. 



PLAT XIII. DEMONSTRATION. 



No. punctures 



No. fruit punctured 



No. sound fruit 



No. fruit 



Per cent free from injury . 



Number of punctured and sound apples, etc., per 

 tree in each plat. 



Tree 

 1. 



2,961 

 1,367 

 499 

 1,866 

 26.79 



Tree 

 2. 



2,391 



755 



553 



1,308 



42.27 



Tree 

 3. 



3,067 

 1,631 

 1,835 

 3,466 

 52.94 



Tree 

 4. 



932 

 441 

 267 

 708 

 33.71 



Tree Tree 

 5. 



3,013 



1,257 



410 



1,667 



24.58 



4,040 

 2,197 

 1,589 

 3,786 

 41.97 



Tree 



7. 



1,486 



612 



451 



1,063 



42.42 



Tree 



2,869 

 1,382 

 1,047 

 2,429 

 43.10 



Total 



for 

 plat. 



20, 759 

 9,642 

 6,651 



16,293 



Total 



per cent 



fruit free 



from 



injury. 



40.82 



PLAT XV. ONE SPRAY. 



No. punctures 



No. fruit punctured 



No. sound fruit 



No. fruit 



Per cent free from injury . 



2,782 

 1,507 

 2,320 

 3,827 

 60.62 



1,800 

 1,788 

 1,869 

 3,657 

 51.10 



633 1,032 

 303 494 

 372 495 

 675 989 

 55.11 50.15 



1,449 

 754 

 925 



1,679 



2,159 

 1,212 

 2,268 

 3,480 



55.09 65.17 



447 

 522 

 969 



3,153 



1,735 

 2,564 

 4,299 

 59.64 



13,995 

 8,240 

 11,335 

 19,575 



57.90 



PLAT XVIL UNSPRAYED. 



No. punctures 



No. fruit punctured 



No. sound fruit 



No. fruit 



Per cent free from injury. 



7,336 



4,497 



2,212 



2,888 



5,030 



6,122 



8,779 



4,904 



41,768 



3,186 



2,226 



1,079 



1,226 



2,399 



2,823 



3,611 



2,107 



18,657 



740 



883 



761 



282 



790 



1,330 



1,510 



688 



6,984 



3,926 



3,109 



1,840 



1,508 



3,189 



4,153 



5,121 



2,795 



25,641 



18.84 



28.40 



41.35 



18.61 



24.77 



32.04 



29.46 



24.61 





27.23 



EXPERIMENTS IN MICHIGAN. 



The experiments in Michigan were carried out in the vicinity of 

 Saugatuck, in the orchard of Mr. E. H. House. The location of the 

 plats in the orchard and of the count trees in the respective plats 

 is shown in figure 37. The size of the trees is illustrated in Plate 

 XI, figure 2. This orchard included trees of the Wagener, Ben Davis, 

 and Baldwin varieties, and an equal number of trees of each variety 

 was used for counts in the respective plats. As in the work else- 

 where, all drop-fruit during the season, as well as that from the trees 



