258 Auxins in Agriculture 



SPRAYS TO MODIFY FLOWER INITIATION 



Whereas auxins can induce flower initiation only in the pine- 

 apple, they can exert a quantitative modification of flower initiation 

 in a large nimiber of plants. There are two techniques which have 

 been used to bring about such a modification, one being the applica- 

 tion of auxin to the growing plant and the other being the soaking 

 of seeds in auxin solutions. 



Some early reports indicated that auxins may slightly hasten 

 (Hitchcock and Zimmerman, 1935) or strongly inhibit flowering 

 (Dostal and Hosek, 1937). Subsequent research has confirmed that the 



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100 MG./L. 



CONG. OF AUXIN 



Fig. 106. The quantitative modification of photoperiodically induced floral 

 initiation in Wintex barley and cocklebur by various concentrations of naphtha- 

 leneacetic acid (Klein, 1951). 



