1917] Fowler-IApman : Optimum Moisture Conditions for Lemon Trees 



Before planting, the roots of the trees were entirely freed from soil 

 and the tops were pruned to a whip. The planting was done on March 

 17, 1915, after which the cylinders were placed in a row (see plate 

 9) in a trench 24 inches deep, in order to prevent the undue heating 

 of the soil from the exposure of the cylinders to the direct sun. Prom 

 the time of planting until June 1, 1915, a soil moisture content of 20 

 per cent based on the dry weight of the soil was maintained in all 

 the cjdinders in order to give all the trees the same start. At tin- 

 last date mentioned the growth of all the trees was sufficiently good 

 and uniform enough to allow of the arrangement for the variation 

 in moisture content in the different cylinders. In order to allow for 

 individual variations among the trees, every 7 moisture content was 

 employed on triplicate trees and the moisture percentages tested were 

 as follows : 



The cylinders are weighed three times per w T eek and the losses of 

 moisture due to evaporation are replaced by additions of the necessary 

 amounts of the ordinary irrigation water employed on the ranch. 

 The weighing is done on steelyards and a derrick is available for 

 raising and lowering the cylinders as desired. The water is added in 

 a depression in the surface soil corresponding in nature to an irri- 

 gation furrow and is applied by means of a very small stream Mowing 

 from a hole in a can used for the purpose. This method is employed 

 to obviate puddling. During rainy weather the cylinders kept at Less 

 than 20 per cent moisture are protected by canvas rootv. Between 

 irrigations the surface of the soil in all the cylinders is kept cultivated. 



Results of the Experiment 

 Seventeen months after the experiment was started or when the 

 trees were two years and five months old, measurements were made 

 and a diagram showing their relative heights at the time is given in 



