Food for best results so far obtained have come from the spray - 



. ing applied about the 1st of February. Of course, 



182 weather conditions must be taken into consideration. 



A rain immediately following the application will wash 



much of the material off of the trees, and it is probable 



that at least a week of clear weather should follow the 



spraying, in order to insure good results. 



In all of this work on spraying a solution of Ni- 

 trate of Soda on the trees a considerable quantity fell 

 to the ground, and the question will be raised as to 

 whether the various effects observed have not been 

 simply the result of the fertilizer action of the Nitrate 

 on the soil. About 7 gallons of the solution were used 

 in spraying each tree, and if the whole of this had gone 

 on the ground it would have amounted to about 7 

 pounds of Nitrate of Soda per tree. The single tree in 

 1912 that had the 50 pounds of Nitrate applied to the 

 soil, therefore, received over seven times the total 

 quantity applied to any single sprayed tree. As has 

 been previously stated, this single, excessively fertilized 

 tree bloomed no earlier than normal, produced no in- 

 creased crop, and showed no improvement in general 

 vigor and appearance; whereas, none of the trees in 

 the sprayed plat failed to respond in all of these par- 

 ticulars. Of course, this single tree test in the appli- 

 cation of Nitrate to the soil is too small an experiment 

 to permit concluding positively that the effects that 

 we have reported from the spraying experiments are 

 of an entirely different nature and belong in a different 

 category from those produced by the ordinary soil 

 application of Nitrate. A careful consideration of the 

 results of ordinary orchard practice in fertilizing seems to 

 make it plain that there is no similarity between them 

 and the results from spraying. For instance, in the 

 usual practice of applying Nitrate of Soda as a fertilizer 

 to apple orchards in the region of Watsonville, Cal., a 

 winter or early spring application does not force the 

 bloom out 10 days or 2 weeks ahead of the normal open- 

 ing period and has had no measurable effect in increas- 

 ing the set of fruit that same year. The fact that the 

 addition of caustic soda or oxalic acid to the Nitrate 

 spray augments these various effects further em- 



