62 
Journal of Agricultural Research 
Vol. XXXI, No. 1 
When put in the lime-sulphur solution the kaolin did not disperse 
as quickly as in water, but on standing overnight it went into sus¬ 
pension readily. The oil was added and emulsified with a bucket 
pump, a satisfactory product resulting. 
Fuller’s earth was used instead of kaolin to make the following 
excellent emulsion: 
To 3 quarts of lime-sulphur solution 1 pound of fuller’s earth was 
added. The clay formed a suspension very readily in the lime- 
sulphur solution, after which 3 quarts of oil was added and the mate¬ 
rials emulsified by pumping twice. 
FIELD EXPERIMENTS 
On February 9, 1923, some of the kaolin emulsion was used for 
experimental spraying on one lemon tree in full bloom and with 
much new growth, two orange trees, and two wild cherry trees 
(Prunus serotina) in full flush of growth. Six days later the sprayed 
trees were examined. The cherry trees were quite badly defoliated, 
but the only damage observed on the citrus trees was the slight 
curling of six leaves on the lemon. No excessive defoliation had 
taken place. 
Normally, a few of the oldest leaves fall after applications of the oil 
sprays in general use. Leaf droppage induced by oil sprays seldom if 
ever occurs until the third day after the spray is applied. The dis¬ 
tinctive features of this type of defoliation are as follows: The leaf 
retains its normal green color, and a few days after the spray is applied 
the blade, while still green, disjoints and falls from the petiole, leaving 
it attached to the branch. It the dosage is excessively strong, or if 
two or more applications of normal dilution are made within two or 
three weeks without rains to remove the excess oil, or if the emulsion 
breaks, severe defoliation and fruit droppage is likely to occur. 
On February 27, 1923, the same trees that were sprayed 18 days 
previously were sprayed again, using the kaolin emulsion 1 to 50, or 
approximately 1 per cent of oil in the diluted spray. For this work 
1*4 pounds of kaolin per gallon of oil were used instead of the 1 pound, 
as of February 9. The material mixed well, but the trees seemed to 
have a greasy appearance after being sprayed, and the drops of spray 
were quite large. There were blooms on Doth the lemon and orange 
trees on the date of spraying. It rained about 5 hours after the spray 
had been applied, and also on the following day. Little or no damage 
was done to these trees. 
On February 13, 1923, the following sprays were applied on bearing 
orange trees: 
3 quarts simple soap emulsion in 50 gallons of water. 
3 quarts of kaolin emulsion in 50 gallons of water. 
3 quarts of kaolin emulsion in 50 gallons of 3-3-50 Bordeaux mixture. 
3 quarts of kaolin emulsion and 2 pounds of soda-sulphur in 50 gallons of water. 
3 quarts of kaolin emulsion and 5 quarts of lime-sulphur solution in 50 gallons 
of water. 
At this time ripe fruit was on the trees, a few tiny bloom buds (not 
full white) were present, and there was considerable new growth. 
Two days later all of the trees were carefully examined to determine 
if any damage had been done. No damage whatever was observed. 
The fruit, new leaves, and tiny buds remained normal, and there was 
no excessive shedding of old leaves. 
