188 



REPORT OF STATE BOARD OF HORTICULTURE. 



on page nine, it will be noted that the Petite prune draws measurably less 

 on the soil than does the Italian. Considered as a whole, our prunes appear 

 to draw more heavily on the soil than do those of California, and it is also 

 interesting to note that in this respect the latter fall below the draught by 

 European prunes, which stand about midway between those of Oregon and 

 California. The conditions in this respect are set forth in the following table : 



TABLE VI. 

 Showing plant food extracted from the soil by certain fruits. 



Fruits. 



Prunes: 



Oregon 



California 



European 



Cherries: 



Oregon 



European 



Strawberries: 



Oregon 



Other localities 



Apples (average) 



Wheat (grain)—. 



Oats (grain) 



Sugar beets 



Total 



ash. Per 



cent. 



.83 

 .49 

 .63 



.;30 



..58 



.42 



.60 



.39 



1.57 



2.98 



1.04 



Per cent, in total ash. 



Potash. 



.53.61 



ft3.83 

 .59.19 



40.37 

 34.83 



.39.86 

 50.00 

 48.72 

 24.84 

 20.80 

 46.17 



/■Aoe- 



phoric 



acid. 



Lime. 



Ifitro- _ , , 



gen per ^«f 



cent. "**• 



15.60 

 14.08 

 10.79 



11.06 

 10.34 



13.99 

 23.31 



2.66 

 44..58 

 24.16 



9.61 



4.66 



Pounds removed in 1 ,000 

 pounds of fruit. 



1.08 



4.20 



.220 

 .162 

 .122 



.180 



.190 

 .150 

 .130 

 2.36 

 2.06 

 2.20 



8.3 

 4.9 

 6.3 



5.0 

 5.8 



4.2 



6.0 



3.9 



15.7 



29.8 



10.4 



Phos- 



Potaslv^ phoric 



acid. 



4.45 

 3.10 

 3.73 



2.01 

 2.00 



1.67 

 3.00 

 1.90 

 3.90 

 6.20 

 4.80 



Lime. 



1.30 

 .68 

 .95 



.55 

 .60 



1.10 

 .10 

 7.00 

 8.20 

 1.00 



.05 



.18 



Nitro- 

 gen. 



2.20 



1.62 

 1.22 



1.69 

 1.80 



1.90 

 1.50 

 1.30 

 23.60 

 20.60 

 2.20 



Potash — In the ash of prunes, cherries, strawberries, and apples, potash 

 is the leading ingredient. In prunes and apples it constitutes about one-half 

 of the total ash; in cherries it constitutes about two-fifths. Attention is 

 called to the difference between the proportion of potash in the ash of the 

 fruits and that of the grains, in the latter constituting only about one-sixth 

 to one-fourth. Attention of horticulturists is especially called to this fact, 

 and still further to the fact that the soil conditions as set forth in Bulletin 

 •50* are such as to demand close attention to this element. The soils of the 

 Willamette Valley are inclined to be weak in this ingredient, due partly to 

 a limited amount in the parent rock and partly to the heavy leaching to 

 which the soils have been subjected. When fertilizers are used on the 

 fruit orchards west of the Cascades, they should invariably be rich in potash. 

 It is quite likely that the low supply of potash of these soils has more or less 

 to do with the smaller sugar content of the Oregon-grown prune, and the 

 tendency to the trees themselves to succumb to fungus attacks. To gain 

 some knowledge of the effect of potash salts applied to prunes, some experi- 

 ments were inaugurated a few years since, but on account of untoward cir- 

 cumstances, the data so far obtainable has not been as definite as is desirable, 

 although the limited results pointed toward an increase in the sugar content 

 of prunes. 



This is in accord with the results obtained at the California station, which 

 indicated a slight increase in the sugar contents of the orange, and also ac- 



*Thls bulletin can be had free on application to the station. 



