i SPRAYING TO CONTROL ENEMIES OF CITRUS TREES. 7 



the fruit from the same trees after having been sprayed ran for the 

 same grades 12.4, 73.1, 14.5 and per cent, respectively. These data, 

 presented by Mr. S. F. Poole before the Florida Horticultural So- 

 ciety, 1 show that spraying raised the percentages of fruit in the 

 first two grades from about 14 to 85.5 per cent, while the same treat- 

 ment lowered the percentage in the inferior third and fourth grades 

 from 86.37 to 14.5 per cent and raised all fruit above the fourth grade. 



In a third grove the grapefruit of the season of 1913-14, which 

 had developed without protection by spraying, gaA T e 0.6, 24," 59, 

 and 16.4 per cent, respectively, in the four grades. The same trees, 

 properly sprayed during 1914, yielded fruits during the 1914-15 

 season which graded for the same grades 27.4, 67.5, 5, and per 

 cent, respectively. In other words, spraying increased the amount of 

 fruit in the first two grades from 24.6 to 94.9 per cent and reduced 

 that in the lower grades from 75.4 to 5 per cent ; increased the first 

 grade from 0.6 to 27.4 per cent and reduced the fourth grade from 

 16.4 per cent to zero. The fruit in the two groves upon which data 

 have been given were graded by the Winter Haven Citrus Growers' 

 Association, and the spraying was done under the direction of Mr. S. 

 F. Poole, of Winter Haven. 



The foregoing data, secured in the same grove two or more years in 

 succession, may raise the question whether the relative abundance 

 of pests, or more favorable climatic conditions, may not have been 

 an important factor in the better crops secured after spraying. 

 Without discussing this point at length the data secured in various 

 groves are given below : 



Grove 1. — During 1913, 900 boxes of fruit picked from unsprayed 

 orange trees in the community graded 32.6 per cent " bright " and 

 67.3 per cent " russet," while 914 boxes picked from a sprayed grove 

 and apparently equally well cared for in other respects graded 90.4 

 per cent " bright " and 9.5 per cent " russet." 



Grove 2. — In the Hill grove at Winter Haven, which was sprayed 

 during 1914, the oranges shipped 60 per cent first, 35 per cent second, 

 and 5 per cent third grade; and the grapefruit, 30 per cent first, 

 67 per cent second, and 3 per cent third grade. The general run of 

 fruit grown in the same vicinity, upon trees in the same general state 

 of culture except that many had not been sprayed at all and others 

 sprayed only indifferently, and packed by the same packing house, 

 may be taken as a fairly good index to the grade of fruit produced 

 during the same season. This fruit shipped 10 per cent first, 62 

 per cent second, and 28 per cent third. 



Grove 3. — In this grapefruit grove one block of trees was sprayed, 

 a second block was left unsprayed after June, while a third block 

 was kept as a check. Aside from spraying, the trees received practi- 



1 Florida Horticultural Society Report, 1915, pp. 130-132. 



