HORTICULTUEE. 641 



potash, and 50 gal. of water, the caustic potash being added to give the spray 

 an insecticide value. About 7 gal. of spray were applied to each tree so that 

 all of the small twigs were drenched. A check row of trees received no winter 

 spraying and several rows of 7 trees each received various applications of crude 

 oil emulsions and soaps. Likewise, to gain some idea of the effect of nitrate of 

 soda used as a fertilizer, 50 lbs. were worked into the soil under one vigorous 

 tree selected from the row adjoining the nitrate sprayed row. By April 7. the 

 trees in the row sprayed with nitrate of soda and lye were well in bloom while 

 those in the check row adjoining and in the remainder of the unsprayed orchard 

 showed only an occasional flower fully opened. When the check row had 

 reached full bloom the row sprayed with a solution of nitrate of soda and lye 

 was practically out of bloom. At first there was relatively little difference in 

 the advancement of the foliage of the sprayed and unsprayed branches. Later 

 in the spring, however, the sprayed trees assumed a more vigorous, green ap- 

 pearance than the check trees. The tree which received 50 lbs. of nitrate of 

 soda applied to the soil showed no greater vigor than the check trees. 



The trees received essentially the same treatment during the summer and were 

 practically free from insect pests. The 7 winter nitrate-sprayed trees produced 

 a total of 40 boxes of apples as compared with a total of about 8 boxes for the 

 check row of 7 trees. The single tree which received the 50 lbs, of nitrate as a 

 soil fertilizer gave no increased yield, whereas none of the trees in the nitrate 

 Hprayed row failed to respond. 



The experiment was enlarged in 1913 to include other nitrogen-bearing mate- 

 rials as well as potash and phosphoric acid sprays. A frost occurred at the 

 time the fruit was setting which ruined the crop. Data were obtained, however, 

 on the effect of the various sprays on the blossoming of the trees in the spring. 

 Plats sprayed with nitrate of soda at the rate of 1 lb. to a gallon came into 

 bloom earlier than the check trees. This effect was more marked in the cases 

 in which the lye was added to the nitrate solution than when it was omitted. 

 Caustic soda appeared to be just as effective as caustic potash. A solution of 

 nitrate of soda at the rate of * lb. to the gallon was less effective and a solu- 

 tion of i lb. to the gallon had practically no effect. Nitrate of soda at the rate 

 of 1 lb. to the gallon to which oxalic acid was added in the preparation of 50 

 lbs. to 125 gal. of solution produced results similar to nitrate of soda plus lye 

 so far as hastening the blooming period was concerned. Lime nitrate, 130 lbs. 

 in 100 gal. of water, and lime cyanid, 92 lbs. in 100 gal. of water, likewise stimu- 

 lated an earlier blooming of the trees. The effects from sulphate of ammonia 

 were much less marked than those from nitrate of soda. The various nitrogen- 

 bearing fertilizer substances carried relatively the same quantities of nitrogen 

 per gallon. Sulphate of potash had some effect in stimulating an early bloom- 

 ing, but double superphosphate did not. Common salt used at the rate of 68 

 lbs. to 100 gal. of water produced a distinct effect. Some cooperative experi- 

 ments were conducted by growers in 1913 on Yellow Bellflower apples, sweet 

 cherries, and pears. 



From the results thus far secured in this work the authors conclude that 

 nitrate spraying of normal trees has brought about an earlier blooming in the 

 case of the Yellow Bellflower apple and various varieties of pears sprayed. 

 The results on stone fruits have not been as striking as those on pears and 

 apples. Aside from the effect on crop production there has also been a very 

 noticeable improvement in the color, abundance, and vigor of the foliage. Ob- 

 servationfl of the original plat of 1912 indicate that the effects obtained by spray- 

 ing with a solution of nitrate of soda may continue over to the second year. 

 It is suggested that at least under certain conditions some varieties of apples 

 and pears that are more or less self-sterile may have their crop production 



