PLANT MORPHOGENESIS FOR SCIENTIFIC MANAGEMENT OF RANGE RESOURCES 



sufficient vegetative development to permit for- 

 mation and translocation of the floral stimulus 

 and, upon rewatering, floral initiation occurred 

 with the first primordia appearing at a lower 

 leaf number. 



More pronounced effects have been observed in 

 species in which flowering can be induced by a 



single inductive cycle. In studies of Lolium temu- 

 lentum L.. Pharbitis nil (L.) and Choisy, and 

 Xantliiwm strum-aman L.. Aspinall and Husain 

 (3) found that stress during the inductive cycle 

 could completely prevent flowering. 



Additional experiments with P. nil showed that 

 stress directly before the inductive period could 



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Watered 5 - Day 7 - Day 

 Daily Cycles Cycles 



Watered 5 "Day 

 Daily Cycles 



7 -Day 

 Cycles 



WATERING REGIMES 



AND DRYING 



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Figure 3. — Mean daily growth of needles (upper box) and roots (lower box) of loblolly and white pine seedlings 

 during each of three drying cycles in three watering regimes. Percentages in histogram bars refer to growth 

 per drying cycle as a percentage of total growth during three cycles (after Kaufmann (16)). 



