Movement of Calcium 



389 



TIBA were applied prior to the application of Ca"*^. Leaves were 

 collected for analysis 9 days after treatment. All treatments and repli- 

 cates were completely randomized. For all tests with the young trees 

 the same control experiment (shown in Figure 1) was used. 



RESULTS 



It can be seen from Figure 1 that in young apricot trees there 

 exists a certain movement of foliarly-applied calcium. The radioac- 

 tivity reached 241 c.p.m. 7 days after treatment, in contrast to that 

 obtained with one-year-old apple trees (12). The effect of DCA was 

 only noted after 3 days, after which a rise in the counts became ap- 

 parent. MH, on the other hand, inhibited movement of Ca'*^ during 

 the first 3 days and later caused it to increase. TIBA was particularly 

 effective (Figure 2). This substance completely inhibited the move- 

 ment of Ca^^ in the first 4 days after treatment, but later caused the 

 movement of Ca to increase to give 28,000 c.p.m. 



Decapitation, coumarin, and MTPA produced rather unexpected 

 results (Figure 3). Decapitation and MTPA increased calcium move- 

 ments during the first 4 days while coumarin was ineffective. But in 

 all three cases the radioactivity dropped again after the initial in- 

 crease, reaching a low of about 50 c.p.m. on the 7th day, as against 



to 



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 tr 

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DAYS AFTER TREATMENT 



Fig. 2. The effect of TIBA upon the basipetal transport of Ca*^ in 1 -year-old 

 apricot trees. 



