1917] Forbes: Irrigation Effects of Copper Compounds Upon Crops 42," 



TABLE XIV (n) 



Squash roots grown in distilled water with CuSOi 



Cu p.p.m. Elongation 24 hrs. Cu p. p.m. 



check 3.6 mm. .0.5 



.01 2.8 .1 



Elongation 24 hrs. 

 1.4 mm. 

 9 



Squasli roots grown in distilled water with Cu(0H)2.CuC0:, 



Cu p.p.m. 

 check 

 .01 



Elongation 24 hrs. 

 3.6 mm. 

 3.8 



Cu p.p.m. 

 .05 

 .1 



Elongation 24 hrs. 

 1.1 mm. 

 .4 



Doubtful stimulation at .01 p.p.m. 



TABLE XIV (o) 

 Corn roots grown in distilled water with CuSOi 



These cultures, while somewhat fragmentary, afford excellent 

 indications of stimulating effects upon plant roots. Excluding 

 squash, which is not satisfactory material to work with, corn and 

 beans show consistent stimulations at very high dilutions. Mea.s- 

 ureraents in all cases are averages of about ten observations. 



TABLE XV 



Summary of Stimulation Effects 



Copper salt 

 used 



Cu(0H),.CuC03 



Cu(OH),.CiiCO. 



Cu(0H),.CuC03 



Cu{OH),.CuCO, 



Cu(OH),.CuC03 



Cu(0H),.CuC03 



Cu(0H),.CuC03 



Cu(0H),.CuC03 



CuSO^ 



Cu(0H),.CuC03 



Character and strength in copper of 

 solution producing stimulation 



