BOARD OF HORTICULTURE 171 



no favorable results whatever. Witii nitrogen, however, the results are different. 

 They have found in all tlieir oxperiments that nitrogen is the element that 

 most nuiekly wears out in the soil and that trees respond to this element more 

 readily than to anything eise, as a nile. 



The results of fertilizing exi>eriments in the west bear out the oonclusions 

 ohtaiued in the east. The Oregon Agricultural Experiment Station started an 

 experiment at Hood River in the year 1914 upon apple trees. These results are 

 to be found in Bulletin No. 141 beginning on page 37. To quote from the intro- 

 ductiou of the article written by C. I. Lewis, we find the foUowing : "The results 

 of two years work previous to 1916, indicated no response of a practical nature 

 by use of potasli or phosphoric acid. On the other hand encouraging results were 

 secured from introtiuction of nitrogen." These experiments were carried on for 

 three years. From 5.2 to 6.7 pounds of nitrate of soda were used to the tree. 

 The orchards were 19 and 12 years of age at the time of beginning. The results 

 obtained were as follows : Leaf and terminal growth two to four times as much 

 as growth of check plot ; yields one and one-half to four times as much as found 

 on the check trees. The fruit buds were more vigorous and the results were 

 reflected in the next year's crop. Color was less brilliant on some of the highly 

 colored apples after two or three heavy appliances of fertilizer. Size of Fruit. — 

 Nitrate Increased tlie size of fruit greatly on the treated orchards. Maturity 

 of Crop. — Check trees seemed to mature their fruit somewhat ealier than the fruit 

 matured on the treated trees. 



Prunes. Experiments were begun in fertilizing prunes in the spring of 

 191S and have continued since. .Tudging from our experience with apples and from 

 the experience of the eastern growers, we did not feel that applications of 

 phosphoric acid and potash would be of value, and so have confined the fertilizer 

 trials to some form of nitrogen-carrying fertilizers such as nitrate of soda or 

 sulphate of ammonia. Nitrate of soda is the fertilizer meant in this woi'k 

 unless otherwise stated. The fertilizer was applied early in the spring about 

 the first of March or the latter part of February in order that the salt might 

 be disolved and washed down into the roots by the rains. The salt was scattered 

 broadcast over a strip four to five feet wide underneath the outer branches and 

 beyond them, because the feeding roots of the trees are usually found in this 

 vicinity for the most part. From SVj to 5 pounds of nitrate was applied per tree. 

 depending upon the age of the tree and its size and rigor. Usually five pounds was 

 considered a reasonable application for trees mature and of good size. 



The results of these applications differed somewhat in orchards that have 

 had different treatments. For orchards that had enjoyed good cai'e and had not 

 been run down, we find that the terminal shoots were increased from one and one- 

 half to two times over the terminals of the check trees, that the color of the foliage 

 was greener. was more leathery in texture, and less inclined to curl up in the 

 Summer time. The size of fruit was increased somewhat both in the fresh and 

 dried stages. The drying time for fruit was the same for the treated and un- 

 treated trees. The maturity of the crop came from a week to ten days later with 

 the treated trees than with those untreated. 



In old. badly run down orchards we found much the same conditions obtained 

 as have been noted above. except there was a much more pronounced gain in 

 yield amounting to as much as 33i/^ per cent in some cases. while the increase 

 in size of fruit came up to an average of 10 per cent. The maturity of the fruit 

 was delayed fully ten days in most cases. Whether this is going to be detrimental 

 or not, remains to be seen. Some growers believe that under ordinary natural 

 conditions, the later maturity would throw prune harvesting too late to be safe. 

 Some work was done on iiears during the summer of 1919, but there were 

 not enough funds available to follow this up. Some observations made on 

 varieties fertilized at that time show us that there seems to be some benefit 

 derived especially upon the fruit buds the following year. 



