98 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



Here, as in the foregoing experiment, the one-spray treatment was 

 more efficient than the demonstration treatment in preventing 

 entrance at the calyx, the difference being 0.10 per cent in favor of 

 the one-spray treatment. However, the one-spray treatment afforded 

 only about one-half as much protection as the demonstration treat- 

 ment against side worminess. In comparing the total efficiency of 

 the two treatments it will be seen that there was a saving of 40.18 

 per cent of the crop in Plat I and of 34.32 per cent in Plat III. 



EXPERIMENTS IN DELAWARE. 



The experiments in Delaware in 1911 were carried out in the 

 orchard of F. C. Bancroft, near Camden, Del. The part of the orchard 

 used for this experiment was a block of about 600 trees somewhat 

 isolated from the rest of the apple orchard. On the north side was 

 a peach orchard, on the east and south a pear orchard, and on the 

 west a cornfield. The orchard was almost level, having just enough 

 slope to drain well. It was well tilled throughout the season. The 

 main variety was Stayman Winesap, with Missouri Pippin used as 

 the principal filler. The trees were 16 years old and were rather 

 large for their age. The plats were laid out diagonally across the 

 orchard, as shown in the accompanying diagram (fig. 25). Trees of 

 each plat from which the fruit was counted throughout the season 

 for records are designated in the diagram by the same numbers which 

 these trees bear in the table. Plat II includes 6,0 trees; Plat III, 

 52 trees; Plat VII, 39 trees, and Plat VIII, 25 trees. The treat- 

 ments to which the respective plats were subjected are shown in 

 Table X. 



Table X. — Treatments and dates of application for the codling moth and the plum 

 curculio. One-spray method. Camden, Del., 1911. 



Dates of application. 



First application, Apr. 27 

 ! before blossoms opened). 



Second application, May 13 

 and 15 (after petals 

 dropped). 



Plat II. 



( Demonstration. ) 



Commercial lime-sulphur 



and arsenate of lead. 



Third application,. Tune 7. 



Fourth application, July 10. 



Scab treatment. Mist spray. 

 Commercial lime-sulphur 

 (1J-50) plus 2 pounds of 

 arsenate of lead. Pres- 

 sure, 140 pounds. 



Not drenched. Mist noz- 

 zles used. Arsenate of 

 lead, 2 pounds to 50 gal- 

 lons commercial lime-sul- 

 phur. Pressure, 140 

 pounds, 



do 



.do. 



Plat VII. 



(One-sprav method.) 



Commercial "lime-sulphur 



and arsenate of lead. 



Scab treatment. Mist spray. 

 Commercial lime-sulphur 

 alone (li-50). Pressure, 

 140 pounds. 



Drenched with arsenate of 

 lead, 2 pounds to 50 gal- 

 lons of commercial lime- 

 sulphur (l}-50). Coarse 

 spray. Bordeaux nozzles. 

 Pressure, 140-150 pounds. 



Commercial lime-sulphur 

 alone (1J-50), Not 

 drenched. 



do 



Plat VIII. 

 (Fnsprayed.) 



T'nsprayed. 



Do. 



Do. 

 Do. 



