PRELIMINARY AND MINOR PAPERS 
WINTER SPRAYING WITH SOLUTIONS OF NITRATE 
OF SODA 1 
By W. S. Ballard, Pathologist , Fruit-Disease Investigations , Bureau of Plant Indus¬ 
try , and W. H. Volck, County Horticultural Commissioner of Santa Cruz County , 
California . 
INTRODUCTION 
Recently several investigators 2 have reported results in shortening 
the rest period of a number of woody plants by immersing the dormant 
shoots in weak nutrient solutions or by injecting solutions of alcohol, 
ether, and various acids into the twigs. These experiments have been 
conducted in the laboratory with short cuttings of the plants. The 
effect of such treatment has been to force the dormant buds out several 
days ahead of the normal opening period. 
During the last two years the writers have obtained similar and addi¬ 
tional results on a much larger scale by spraying dormant fruit trees 
with strong solutions of certain commercial fertilizers, especially nitrate 
of soda. Since these experiments have been conducted on the entire 
trees in the orchard, it has been possible to observe the effects throughout 
the whole season. The investigations have not yet been carried far 
enough to permit drawing any conclusions regarding the physiologic 
action of such spraying, but because of its practical value these prelimi¬ 
nary results seem deserving of attention at this time. 
EXPERIMENTS IN 1912 
In the course of the investigations of the writers on the control of 
apple powdery mildew in the Pajaro Valley, Cal., it became evident 
that the general vigor of the tree and the thriftiness of the foliage growth 
had much to do with the success of the summer spraying treatment 
for the control of the mildew, and after a number of experiments in 
applying plant-food materials to the foliage in the form of summer 
sprays, and after seeing that certain crude-oil emulsions used as dormant 
sprays had a marked effect in stimulating an increased vigor of the trees 
the following spring, it was decided to try the effect of a strong solution 
of nitrate of soda as a winter or dormant spray. Caustic potash (potash 
lye) was also added for the purpose of giving the spray an insecticide 
value. The mixture was prepared according to the following formula: 
Nitrate of soda. 50 pounds. 
Caustic potash. 7 pounds. 
Water. 50 gallons. 
The experiment was conducted in a Yellow Bellflower apple orchard 
owned by Mr. O. D. Stoesser, of Watsonville, Cal. This orchard is 
1 These investigations were conducted in cooperation between the Office of Fruit-Disease Investi¬ 
gations of the Bureau of Plant Industry and the Office of the County Horticultural Commissioner of Santa 
Cruz County, located at Watsonville, Cal. The writers 5 names appear above in alphabetical order. 
2 See references to literature, p. 444. 
Journal of Agricultural Research, 
Dept, of Agriculture, Washington, D. C. 
(437) 
Vol. I, No. s 
Feb. 16,1914 
G—14 
