CALDECOTT AND NORTH: RADIO-SENSITIVITY OF SEEDS 



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I5,000r +- anoerobic hydration 

 x = 9.6 cm. 



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SEEDLING HEIGHT (CM.) 



Figure 9. — The effect of a 75°C pre-irradiation heat treatment on the 

 injury to seeds that are hydrated anaerobically before and after storage. 



heated but in which germination was delayed for 48 hours (Figures 

 8 and 9, part C). Second, pre-irradiation heat treatment completely 

 eliminated the increase in injury that usually occurs when seeds are 

 stored after irradiation (Figures 8 and 9, compare parts A and C with 



