BULLETIN 231] WALNUT CULTURE IN CALIFORNIA. 187 



The most valuable results obtained from the experiment were, first, 

 the demonstration of the variation in production in seedling trees, and 

 second, the relation of soil texture to walnut production. On the first 

 point we may repeat what has been said, that the various trees varied 

 from one to 117-J pounds in their total production. 



On a block of 400 trees on fairly uniform soil 148 trees, or 37 per 

 cent, produced less than 10 pounds each; 118 trees, or 29J per cent, 

 produced from 10 to 25 pounds each; 82 trees, or 20 per cent, pro- 

 duced from 25 to 50 pounds each ; 26 trees, or 9 per cent, produced 50 

 to 60 pounds each ; 10 trees, or 2J- per cent, produced 60 to 75 pounds 

 each; 5 trees, or 1^ per cent, produced 75 to 100 pounds each; and 1 

 tree, or | per cent, produced over 100 pounds. 



To show further the variation in production in seedling trees under 

 almost exactly the same conditions, the crop from adjacent trees in 

 some of the individual rows may be stated. In row 20, for instance, 

 the production in pounds per trees was as follows: 1.4, 16, 45.6, 10.5, 

 21.5, 97.4, 20.5, 8, 26.3, 0, 16.4, 1, 18.6, 13.5, 10.6, 21.5, 2, 31, .7, 14.8. 

 Another row, 3, 72.5, 32, 27.5, 58.9, 9.8, 69.5, 22.2, 30.5, 8, 44.5, 38.5, 

 20.1, 19.1, 13.5, 34.8, 5.5. In the case of the 117.5 pound tree, the 6 

 trees surrounding it produced as follows : 6, 24, 14, 28.5, 27, 23. These 

 were all Santa Barbara Soft Shell seedling trees in their eighth year 

 in the orchard at the time these weighings were made. The same vari- 

 ation runs through all the figures and it is impossible to deduce any 

 reliable conclusions as to the effect of the fertilizers. A study of the 

 figures obtained, taken together with an examination of the trees as 

 to general appearance, gives one a fairly strong impression that the 

 greatest benefits were derived from the application of stable manure 

 and that of nitrogenous materials. Such results would certainly be 

 expected, especially in this rather sandy land, yet even so, it is sur- 

 prising to note the lack of pronounced results from the application 

 of the large quantities of these materials which were used. For 

 instance, in the plot of 42 trees which received during the two years 

 40 pounds of nitrate of soda, 60 pounds of superphosphate and 14 

 pounds of sulphate of potash per tree, the average product of the 42 

 trees was about 28 pounds of nuts. In the plot which received the 

 same minus the nitrate of soda, the average product was exactly the 

 same ; in that which received the same minus the potash the average 

 was 33 pounds, while in that which received the same minus the 

 superphosphate it was also 33 pounds. These plots were all near 

 together on the same type of soil and with trees as uniform in appear- 

 ance as can be found in any seedling walnut grove. The stable 

 manure plot averaged about 31 pounds, while the adjacent check plot 



