104 



Experiment in Jolly Orchard, Olney, Illinois, 

 Spring of 1922 



A block of twenty-five-year old Ben Davis and Grimes Golden apple 

 trees was chosen for this experiment in what was known as the Jolly 

 orchard at Olney. These trees were heavily infested, most of them having 

 a considerable portion of the tree incrusted. Those selected for the ex- 

 periment were divided into blocks five rows long by four rows wide, the 

 center row being Grimes Golden, and the two outside rows Ben Davis. 

 The infested branches, which were later cut for scale examinations, were 

 taken from the inside rows of the blocks. 



The first sprays were applied on March 28, all blocks being treated 

 within a week. Special attention was given to the application of the 

 sprays. All trees were sprayed with rods, and the operator was followed 

 by a third man to see that no part of the tree remained unsprayed. In 

 the course of this work, we found that slightly more of the oil .sprays 

 was required to cover trees of a given size than was the case with the 

 lime sulfur sprays. For the twenty-five-year old trees, twenty gallons 

 per tree of the oil were required and fifteen to seventeen gallons per tree 

 of lime sulfur. Forty-seven days after the treatment, samples of scale- 

 infested twigs were taken from various parts of the trees on the inner 

 rows of all of the blocks and examined for living and dead scale. The re- 

 sults of these examinations, expressed in percent of living scale, are 

 shown in Table I. 



Table I 



Scalecide (1 to 15) 



Spray Emulsion (1 to 15) 



Diamond Paraffin oil, flsh-oll soap emulsion (2%).., 

 Junior Red Engine-oil, fish-oil soap emulsion (2%). 

 Commercial liquid lime-sulfur (32 Baume, 1 to 8) . • 

 Soluble sulfur, Niagara (15 lbs. to 50 gals, water).. 



Dry lime-sulfur (15 to 50 ) 



Check, no treatment 



Percent of 

 live scale 



.5 

 .4 

 1.5 

 7. 

 11. 

 18.5 

 41. 

 50. 



The following conclusions, standing in the order of their import- 

 ance, may be noted : 



1. The oil sprays were superior to the sulfurs. 



2. The oil emulsion made from Oil No. 1, the brand used in 

 most cases in Florida, was almost as effective as the miscible oils. 



3. Dry lime sulfur was not as good as liquid lime sulfur. 



The fact that even after the most careful spraying, 11% of the 

 scale was still alive on trees treated with lime sulfur, explained the 

 failure of some growers to control scale where this material had been 

 used. No further experiments were made in this orchard during 1922, 

 but the remainder of it was sprayed thoroughly with commercial lime 

 sulfur, used at 1 to 6, and in some cases at 1 to 4, dilution. 



