FORTIETH ANNUAL REPORT. 



171 



RESULTS OF SPRAYING EXPERIMENTS AND DEMONSTRATIONS DURING 1910. 



During the season of 1910 the same experiments were carried out 

 as during 1909, whict were reported in Circular 120 of the Bureau of 

 Entomology and in Bulletin 174 of the Bureau of Plant Industrv', and 

 in addition the recommendations given in these publications were put 

 in effect on a commercial scale to serve as an object lesson for growers. 

 During 1909 the experiments made in the Hale orchard at Fort Valley, 

 Ga., included the treatment of 1,100 Elberta trees for the control of 

 peach scab, brown-rot, and curculio. The self-boiled lime-sulphur mix- 

 ture (8-8-50) plus 2 pounds of arsenate of lead was used. 



This combined treatment gave the folloAving results: At picking time 

 95.5 p;er cent of the fruit on the sprayed block was free from brown-rot, 

 93.5 per cent free from scab, and 72.5 per cent free from curculio. On 

 the unsprayed block only 37 per cent of the fruit was free from brown- 

 rot, 1 per cent free from scab, and 2.5 per cent free from curculio in- 

 jury. In packing the fruit for market it was found that the yield of 

 merchantable fruit on the sprayed block was ten times as great as 

 from the unsprayed block containing the same number of trees. 



During the season of 1910 neither the brown-rot nor the plum cur- 

 culio was so abundant in Georgia as the year previous, and the contrast 

 between the sprayed and unsprayed blocks was, therefore, not so strik- 

 ing. Nevertheless, the very satisfactory results obtained fully substan- 

 tiated the conclusions previously reached as to the value of spraying. 



The work in Georgia was carried out at Fort Valley, Barnesville, and 

 at Baldwin. At Fort Valley a block of 1,001 nine-3ear-old Elberta 

 trees was treated in the orchard of the United Orchard Company. In 

 addition to numerous experiments planned to show the effect of treat- 

 ments at different times and with different mixtures, the demonstration 

 treatment was put in effect on a block of 848 Elberta trees, a similar 

 number being left unsprayed for purposes of comparison. The trees 

 Avere sprayed (1) as the cah^xes were shedding, April 1, with 2 pounds 

 of arsenate of lead and 3 pounds of lime in each 50 gallons of water, 

 (2) two to three weeks later, April 19 and 20, with 8-8-50 self-boiled 

 lime-sulphur and 2 pounds of arsenate of lead; (3) on June 17, about 

 a month before the fruit ripened, Avith self-boiled lime-sulphur alone. 



In order to determine the effect of the treatments, the fruit at pick- 

 ing time (July 12 to 15) was gathered from 68 trees in the sprayed 

 block and from 63 trees in the unsprayed block. This fruit was care- 



fully graded into "merchantable" and 

 in Table III. 



"culls," 



with the results shown 



TABLE III. — Results of demonstration spraying in the peach orchard of the United Orchard 



Company, Fort Valley, Ga., 1910. 



Plat. 



68 trees (sprayed). . . . 

 63 trees (not sprayed) 



Yield. 



Bushels. 



101 



92 



Merchant- 

 able fruit. 



Per cent. 

 86. 2 

 54.6 



Culls. 



Per cent. 

 13.7 

 46.4 



Fruit af- 

 fected with 

 brown-rot. 



Per cent. 



5.3 



20.0 



It will be noted that from the 08 sprayed trees there was a total yield 

 of 101 bushels, of which 86.2 per cent was merchantable and 13.7 per 



