44 MISSOURI AGR. EXP. STA. RESEARCH BULLETIN NO. 21 



On January 22, 1914, a number of very vigorous one-year-old 

 twigs were collected from a Jonathan apple tree. Some very weak 

 twigs were also selected from the same tree. The former were 

 more than one meter long, while the latter were only about 15 to 

 20 cm. in length. These twigs were placed in beakers containing 

 water and they were allowed to grow in the greenhouse. The 

 photograph (Fig. 9) shows the growth made by each set after one 

 month. It is seen that the terminal buds of the vigorous twigs 

 (A) made much more growth than the weak twigs (B). The former 

 opened within a few days after they were brought into the green- 

 house; the latter first burst after two weeks. 



Did the tall twigs finish their rest before the weak twigs? Did 

 they have a rest period at all, or did they stop growth because they 

 were forced to do so by the cold weather? The terminal buds were 

 not as well protected by their natural coverings as the weaker twigs. 

 Apparently growth in the strong twigs stopped rather suddenly so 

 that no time was left to finish out the buds as in the case of weaker 

 twigs. 



NEW METHODS FOR BREAKING THE REST PERIOD 



A few new methods of forcing growth in dormant twigs were 

 employed with more or less success but in no case was any attempt 

 made to determine the exact dose to produce the most effective 

 results. However, there is little doubt that for each treatment there 

 is an optimum dosage which will vary with the species, the season 

 and perhaps with other factors. The main object of these tests was 

 to determine if the treatments given would actually stimulate 

 growth. Relatively little attention was given to the degree of 

 stimulation. 



Treating apple twigs by immersion in solutions of 0.25, 0.125, 

 .0625 and .03125 per cent CuSO4 for twelve hours on December 7, 

 1913, produced earlier growth than untreated material. The 

 stronger the concentration the better the results. The same treat- 

 ment applied to Forsythia at the same time proved toxic to the buds. 



Immersing in 0.5 per cent HC1 for sixteen hours was effective in 

 forcing apple buds as well as Forsythia. CuSO4 treatments appar- 

 ently were more effective than the HC1 bath on the apple. 



On December 17, 1913, Fraxinus Ornus twigs were immersed 

 in 5 per cent, 1 per cent and 0.5 per cent oxalic acid for twelve 

 hours after which they were placed in water in the greenhouse. 

 After twenty-five days, the terminal buds of twigs treated with the 

 one per cent and the 0.5 per cent solutions became active, while 



