-18- 
were somewhat distorted. Higher strengths caused some growth retarda- 
tion in beets, carrots, muskmelons, and potatoes. Tests are under way 
in which excessive quantities of DDT were applied to the soil under 
apple and peach trees, to simulate the accumulation that might occur 
over a period of years if DDT should oome into general use. Thus far 
no injury has become evident*— Baker and Porter (81). 
Radishes grown in soil containing 250 pounds of DDT per acre, 
thoroughly washed, and then fed to three-fourths grown larvae of the 
white fringed beetle (Pantomorus leucoloma Boh«) caused no mortality in 
33 days. Germination of cotton, corn, peanut, oat, and cowpea seeds was 
not affected by treating tnem with a 50 percent DDT dust before plant- 
ing. Austrian winter peas, peanuts, rice, sweetpotato, white potato, 
cotton, corn, cowpea, soybean, radish, and blue lupine have been grown 
in soil treated with various dosages of DDT up to 100 pounds per acre, 
and in some cases up to 250 pounds per acre, without visible injury. 
On the other hand, injury to young rye plants, consisting of redden- 
ing of foliage, twisting of leaves, poor growth, and dying of some 
plants, occurred in pot and field-plot tests in which DDT in dust or 
emulsified form was used as a soil insecticide at rates of 10 to 250 
pounds per acre. Emulsions caused very pronounced injury even at the 
10-pound dosage. The injury caused by the dust treatments was slight 
at the 10-pound dosage but increased with the dosage.— Packard (285 ) . 
Eight applications of 5 percent DDT in light summer spray oil, 
average about -g- gallon per acre, made by hand atomizer from June 6 to 
August 1, did not injure strawberries, asparagus, muskmelons, mangels, 
onions, kale, broccoli, cabbage, eggplant, squash, cucumber, peas, let- 
tuce, turnips, tomatoes, carrots, beets, corn, beans, lima beans, or 
potatoes. On soybeans (Bansii) there was definite burn, which was 
probably due to the oil.— Gray (188 ). 
The germination of rioe seed was not materially affected by suspen- 
sions of 0.1 to 100 p.p.m. of DDT» Growth of microorganisms common to 
soil was not significantly affected by water suspension of 10 and 100 
p. p.m. of DDT. Soil pretreated with a DDT-oil emulsion (5 percent DDT 
and 0.5 percent emulsifier in No. 2 Diesel fuel oil applied at the rate 
of 1 part to 20 million parts of water) supported growth of rice and 
barley comparable with that produced on similar untreated soil.— Broyer 
(97). 
A pple . A moderate amount of foliage spot-type burn followed the 
fourth" application of DDT in oil (2 oz. per 100 gal.) on Delicious, but 
not on Jonathan or Hubbardson. No similar injury was produced by lead 
or by oil-nicotine sprays on comparable trees in the same orchard.— 
Cleveland (114). 
