February, ’23] 
PARROTT & GLASGOW: TOBACCO DUST 
93 
Table 1. The Effect of Applications on Spirea Aphis 
Number of Percentage of 
insects aphids killed 
Reground tobacco dust, less than 50-mesh. 778 8.5 
Reground tobacco dust, 50-mesh.,. 747 16.3 
Reground tobacco dust, 100-mesh.1036 73.7 
Reground tobacco dust, 150-mesh.1019 76.8 
Reground tobacco dust, 200-mesh. .1391 89.7 
Reground tobacco dust, 100-mesh with 10-percent lime hydrate.1018 78.0 
Reground tobacco dust, 150-mesh with 10-percent lime hydrate. 979 83.0 
Reground tobacco dust, 200-mesh with 10-percent lime hydrate. 1566 84.0 
Kaolin with 1 percent nicotine. .......1699 98.8 
Lime carbonate with 1 percent nicotine.1706 99.1 
Lime hydrate with 1 percent nicotine.1475 96.8 
Sulfur with 1 percent nicotine.1681 96.8 
Experiments with the Currant Aphis 
Dust mixtures were applied at the rate of 1 pound per bush and spray 
mixtures at the rate of 2H gallons per bush. Three applications were 
made to all the plats. With the possible exception of the sulfur-lead- 
arsenate dust containing 0.5 percent nicotine, the various preparations 
proved about equally effective in protecting currants from important 
curling of i.he foliage. At the conclusion of the period of infestation 
counts were made of the healthy and injured leaves on each bush. The 
data are given in Table 2. 
Table 2. Effectiveness of Spray and Dust Mixtures in Controlling ti-ie Currant Aphis 
Percentage 
Treatment of injured 
leaves per bush 
Spray (1 pint nicotine sulfate with 6 lbs. soap to 100 gals, water). 1.01 
Dust (90-10 mixture with 0.5 percent nicotine). 2.82 
Dust (90-10 mixture with 1.0 percent nicotine). .41 
Dust (90-10 mixture with 2.0 percent nicotine). .13 
Dust (reground tobacco containing 1.0 percent nicotine). .20 
Check No treatment. 27.16 
Experiments with the Rosy Aphis 
«2 
In this series of tests a number of Greening trees were dusted with 
reground tobacco and others were sprayed with lime-sulfur at the usual 
dilution containing tobacco dust. For purposes of comparison, ap¬ 
plications were made of lime-sulfur carrying nicotine sulfate and dust 
Table 3. Influence of Delayed Dormant Application of Dust and Spray Mixtures on Rosy 
Aphis 
Number Number of Average No. Average Percentage 
of plat Treatment trees of apples No. of aphis 
examined per tree aphis apples apples 
1 
Spray (tobacco dust, 40 lbs. per 100 gals, of 
sulfur-glue mixture). 
8 
2207 
43 
1.95 
2 
Spray (tobacco dust, 40 lbs. per 100 gals, of 
lime-sulfur 1-40). 
8 
867 
22 
2.65 
3 
Spray (tobacco dust, 25 lbs. per 100 gals, of 
lime-sulfur 1-40). 
8 
925 
11 
1.25 
4 
Spray (nicotine sulfate, K pint per 100 gals, of 
lime-sulfur 1-40). 
32 
1086 
20 
1.99 
5 
Dust (reground tobacco dust, 5 lbs. per tree). . 
, 8 
1408 
261 
19.02 
6 
Dust (90-10 mixture with 2 percent nicotine).. 
12 
1735 
324 
19.16 
7 
Dust (90-10 mixture with 1 percent nicotine).. 
12 
1211 
347 
27.73 
8 
Dust (90-10 mixture with 0.5 percent nicotine). 14 
1797 
487 
29.74 
9 
Check. 
. 4 
2225 
719 
32.31 
