742 EXPERIMENT STATION EECORD. 



orchard plat by plat and some deductions are made relative to the influence 

 of the various treatments on the formation of fruit buds at this stage of the 

 investigation. 



The results thus far indicate that clean cultivation up to July 10, followed 

 by a cover crop of crimson clover, has given the greatest amount of fruit, 

 although the plat on which cultivation and cover cropping was practiced 2 

 years in 3 gave almost as good results. In this orchard the inability of apple 

 trees to produce fruit buds when grown in sod as compared with any of the 

 systems of cultivation employed has been clearly and completely proved. 

 Although the addition of fertilizers failed to stimulate a greater production 

 of fruit buds, they improved the size and quality of the fruit. The largest 

 quantity of No. 1 fruit per tree was produced in the limed plat, which plat 

 included a section of the fertilized plats, and the next largest quantity of No. 1 

 fruit was produced in the plat receiving an excess of potash. Tlie fewest No. 1 

 apples but the most highly colored fruit were produced by the sod plat. Excess 

 phosphoric acid appeared to produce the smallest apples, though the fruit ran 

 uniformly of good quality. The indications are that spraying has only an 

 indirect influence on fruit bud formation. A general review of all results for 

 1910 indicates that a plentiful supply of moisture, the result of cultivation, was 

 the most influential factor in stimulating the production of fruit buds. The 

 addition of nitrogen in the form of a cover crop appears to be the second most 

 important factor in this regard. 



Variability of frost injury on fruit buds, Philfna F. Homee (Mo. Weather 

 Rev., 39 {1911), Xo. 4, PP- 599-601). — A review is given of the Itnown causes of 

 the differences in frost Injury, together with observations on the variations in 

 the killing power of frost that have taken place in the past 5 years on the 

 Timpanogos Fruit Farm, at Pleasant Grove, Utah. 



Preliminary frost fighting studies in the Rogue River Valley, C I. Lewis 

 and F. R. Brown (Oregon 8ta. Bui. 110, pp. 62, figs. 19). — Preliminary orchard 

 heating tests conducted in the springs of 1909 and 1911 are reported, together 

 with observations taken in the different orchards throughout the valley, includ- 

 ing experiences of some of the growers. A brief statement is also given of 

 conditions in the Willamette Valley. 



The tests made in 1909 were largely negative, owing to an inferior grade of 

 oil. lack of sufficient heaters, and unusual low temperatures. In 1911 two or- 

 chards, consisting of 6i acres of 17-year-old pears and 2 acres of apples, were 

 heated with 2 types of sheet-iron heaters, one of which was the open lard-pail 

 type and the other contained a center draft. Two grades of oil were used, 

 28° distillate and 20° " slop " distillate. 



Although the latter part of March was very warm. 6 frosts were recorded 

 from April 12 to May 5, the lowest temperatures for each being 29, 27, 25J, 28, 

 26, and 31° F., respectively. At 30° outside temperature no increase was ob- 

 tained with 20 heaters per acre. With 39 center-draft heaters per acre an 

 average increase of 1° was obtained. One hundred of these heaters arranged 

 17 by 25 ft. increased the temperature 3*°, and when arranged 21 by 21 ft. 

 increased the temperature 4.1°. The lard-pail type of heater, when used at the 

 rate of 100 per acre, arranged 17 by 25 ft, gave an average increase of 4". 

 When a carbon arrester was placed on these heaters, however, the increase 

 was only 1.3°. 



The heavy fuel oil left an inch of residue after each firing which would not 

 burn, and if left in the heater decreased the burning time. Oils with a paraffin 

 base are to be preferred to those having an asphalt base. Oil is considered the 

 best fuel, as less help is required and an even temperature may be niaiutained. 

 The average cost per acre for a 4-hour-period is $5.10 for oil, not counting the 

 equipment. Heaters cost about 20 cts. each. 



