FIFTY-FIRST ANNUAL REPORT. 23 



11. Materials may be spread inlhollow circlesXover the tree roots 

 or over the full tree square, depending upon the size of the tree and the 

 amount of ground cover it is desired to invigorate. 



12. Because f(Mtilization has invigorated trees, produced more healthy 

 foliage, increased crops, induced more regular bearing, and stimulated 

 better growth in cover crops and sod, the practice has become as im- 

 portant and as regular in many sections as spraying and pruning. 



The following questions were asked Professor Cruickshank after his 

 talk: 



Greening: In your northern Ohio orchards does the use of commer- 

 cial fertilizers delay the peach crop? 



Cruickshank: There has not been much done with peaches. How 

 much the peach crop is delayed, I do not know because I have not fol- 

 lowed this particular work up, but those growers are using these ferti- 

 lizers in lesser amounts on account of severer pruning. A reasonable 

 application would not delay the maturity more than three or four days. 

 If too much is used it would delay the crop more and it might be inclined 

 to bring them on all at once. 



Perkins: How does the application of these materials affect pears? 



Cruickshank: We do not grow many pears, but the men who are 

 growing them are getting results similar to those on apples from the 

 application of these fertilizers. 



Member: Is there any difference in the length of time in getting 

 results using nitrate of soda or sulphate of ammonia? 



Cruickshank: We have noticed no particular difference. 



Dow: Do you know whether the nitrate of soda acts as a direct 

 fertilizer or in an indirect way in neutralizing the toxic effect of the June 

 grass? We all know that when we plow up a June grass sod the foliage 

 changes from a yellow to a deep green. The Rothamstead Experiment 

 Station in England has conclusively proven that there is a toxic effect 

 from June grass. 



I do not believe that we know as yet enough of the effects of toxicity 

 to warrant the statement that it is an important factor in the lesser 

 crops found in sod orchards in comparison with those in cultivated 

 orchards. 



For my own part, I am able to consider the subject better from other 

 angles. We find that sulphate of ammonia will give us equally bene- 

 ficial results as does nitrate of soda which I think would get around the 

 factor of oxidation. Further, an experiment in southern Ohio reported 

 in Ohio Bulletin No. 339 shows through a five year period that fertilized 

 cultivated trees produced about forty per cent more fruit than unfertilized 

 cultivated trees. The report of the Hood River Branch of the Oregon 

 Agricultural Experiment Station for 1914-1915 says, "In every experi- 

 ment in which nitrate of soda was applied to apple orchards in Hood 

 River the plots to which this element was applied show a marked increase 

 in vigor of growth of the trees, a decided improvement in color of the 

 foliage, and in most instances a noticeable increase in production of fruit. 

 The most pronounced results were derived from its application to ma- 

 tured trees of low vitality in orchards that have been kept continuously 

 under clean cultivation and without irrigation, since planting." 



