Effects of Medium on Rooting 



As mentioned in the publication cited above (2). earlier results had 

 shown sawdust to have promise as a rooting medium in contrast to sand. 

 Prior to this published report, preliminary experiments had shown mixtures 

 of sand and peat in various proportions, and waste bark to be inferior to 

 sand alone. In order to definitely establish the value of sawdust in this re- 

 spect, for two seasons a comparison of sawdust was made with sand. Separ- 

 ate portions of two different beds were filled with each material. Both 

 media were tested with nearly equal numbers of cuttings from each clonal 

 source. Those cuttings were given similar treatment. In another season a 

 similar comparison was made of perlite with sawdust. 



The results of these tests are summarized in Table 2. These show that 

 sawdust is superior to either of these other two materials as a rooting 

 medium under the conditions of these experiments. It may be mentioned 

 that sawdust has other advantages. One is that it is much lighter in weight 

 than sand, and therefore easier to handle and store. It is usually cheaper 

 than other media and easily obtainable. 



Table 2. Effect of Medium on Rooting of Sugar Maple Cuttings 



Effect of Growth Regulators 



The data reported previously (2) had shown some slight advantage for 

 growth regulator treatments, the best one being indolbutyric acid at 0.1 

 percent strength (quick-dip method). For further information, tests were 

 continued with a few of these substances for two more seasons. Also, on 

 recommendation by Dr. P. W. Zimmerman of the Boyce Thompson Insti- 

 tute (personal comitiunication ) , the dry powder manufactured by Merck 

 and Co., knowir as Hormodin No. 3. was tested for two additional seasons. 

 The results are summarized in Table 3. Here again, some slight superiority 

 is shown for one of the growth regulator treatments over the controls, but 

 probably not enough to warrant the extra labor and expense of treatment 

 with these materials. 



