300 Twenty-seventh Annual Report 



plant stimulation with non-essential elements 

 The results obtained by Japanese and French investigators in the 

 stimulation of plant growth by various non-essential elements were 

 reviewed by Mr. P. W. Moore, a graduate student and fellow in the 

 department. The original articles were all carefully studied and a 

 critique in manuscript form made available. Experimental work was 

 confined to boric acid and potassium iodide. Unquestionable stimula- 

 tion, especially of the root system, in both water and soil cultures was 

 obtained, and stimulation with boric acid appeared to give considerable 

 promise of practical use in the culture of root crops, especially radishes. 

 Mr. Moore's own conclusions are as follows : 



"Both boric acid and potassium iodide are of undoubted value, at least in 

 the culture of radishes. The optimum concentration for both appeared to be in 

 the neighborhood of 750 grams (about 1% pounds) per acre. For potassium 

 iodide this is about ten times the dose recommended by the Japanese investigators. 

 It corresponds fairly well with the dose of boric acid recommended by Agulhon 

 for radishes. The bottoms are increased more than the tops. There seems to 

 be no advantage in using both stimulants at once. If boron and iodine each 

 perform some special function in the plant, then both of them together should 

 be more beneficial than either by itself. Accordingly it is difficult to explain in 

 this way the effect of stimulants, at least in the case of boron and iodine." 



CHANGES IN CHEMICAL CHARACTER OF THE TEMPE DRAINAGE DITCH 



WATER 



The opening of a ditch draining the alkaline area south of Teinpe 

 during the last summer offered unusual opportunity to study quanti- 

 tatively the effect of draininge reclamation on the composition of the 

 water and soil of the drained area. Consequently soon after water 

 began to fiow in the new ditch monthly samples were collected and 

 analyzed. The results of the analyses are shown in Table XXII. 



The very briny flow shown by the first analyses improved rapidly 

 in composition as the ditch progressed and the flow increased. In 

 September an unusually heavy rainfall raised the water table in the 

 district and undoubtedly increased the flow, although there was no 

 previous flow with which to compare, since the ditch is under constritc- 

 tion and new areas are being added daily. The character of the drain- 

 age water has improved each month until in December the dissolved 

 salts (or alkali) amounted to less than one-fifth that in the original 

 flow. This is due to the improved character of the drainage encountered 

 at or near the head of the ditch rather than to actual sweetening of the 

 drainage at any one point, although such sweetening is undoubtedly 

 occurring. After the completion of the ditch, improvement in the 

 quality of the flow will be attributable to draining off the stagnant 

 alkaline water and its replacement with purer drainage water. The re- 

 markable change in composition with the probability of further im- 



