FIFTY-FIRST ANNTTAL REPORT. 19 



the nitrate and acid pliosphate plats. It nia}- be found out later then 

 that these materials eonit)in(>d with acid phosphate and nitrate of soda 

 or suljihate of ammonia would be an excellent ap})li('ation. The bone 

 and t;uikaf;"<> would t(Mid to cnrry ovei- fi'om year to year and to aecuinu- 

 late more in the soil and thus ^\\'e more reserve of plant food materials. 

 There are as yet no experimental results in connection with the com- 

 parison of the values of nitrate of soda and sidphate of ammonia as 

 carriers of quickly available nitrogen. However, both materials have 

 been used in general practice in all sections of the state. There appears 

 to be no essential difference as to their beneficial effects in improving 

 the vigor of trees and their production. The factor that has governed 

 the choice by Ohio growers during the past few years has been the price. 

 As sulphate of ammonia has been a little cheaper, large amounts of it 

 have been used. Anything which I ma}' say in general regarding the 

 use of quickly available nitrogenous fertilizers applies equally to sul- 

 phate of ammonia and nitrate of soda. 



It has been, therefore, the fertilizers containing nitrogen in a quickly 

 available form which have given us such remarkably good results in 

 Ohio. The first year that nitrate of soda was used experimentally it 

 was applied after the trees had bloomed. This resulted in a general 

 toning up of the trees but gave little advantage in the way of increased 

 production except that the apples were of better size. Since then the 

 practice has been to make the application from two to three weeks 

 previous to blossoming. This has operated to increase materially the set 

 of fruit and has enabled the trees to carry this increased set to maturity, 

 thus providing much larger crops. 



It is quite generally agreed that our fruit trees at time of blossoming 

 need considerable food materials in the spurs for satisfactory setting. 

 At this season of the year there is little nitrification taking place in the 

 soil and what is used is only that which may have been stored in the 

 trees from the previous season's work. Unless, therefore, the soils have 

 been strong and the growing conditions of the trees favorable there may 

 be an insufficiency of stored-up food. This will mean a lack of full 

 capacity on the part of the tree for fruit setting and there will be a lack 

 of it in proportion to the lack of materials stored. Quickly available 

 nitrogenous fertilizers applied somewhat previous to the blossoming 

 period will be taken up by the tree and carried to the spurs in time to 

 afford them more of this food in case it is needed. This has doubtless 

 been the reason why the application of nitrate of soda or sulphate of 

 ammonia has produced such remarkable results the same year that it 

 was applied. In addition to a better set of fruit, it should be remem- 

 bered that most of the spur growth for the next A^ear's crop is made 

 early in the season and a sufficiency of plant food while these spurs are 

 developing should tend to better fruit bud development for the subse- 

 quent crop. These appear to be sufficient reasons for applying nitro- 

 genous fertilizers in advance of bloom. 



The practice in Ohio has been to use about five pounds of nitrate of 

 soda or about three and three-fourths pounds of sulphate of ammonia 

 per tree per year. These figures apply to trees about twenty to twenty 

 five feet high. These amounts should, of course, be modified in propor- 

 tion to the size of the tree and general fertility conditions in the soil. 

 Many of our growers are using as high as ten pounds per tree. The 



