Nov. i, 1920 



Effect of Drying Disinfected Seed Wheat 



217 



mination of the injured seed lots was retarded, often several days, and 

 they produced a considerable number of spindling or short plants which 

 apparently never would be strong (Pi. 38, A). 



The injury from drying, either in storage or in the soil, is greater the 

 more concentrated the solution used. The data given in Table IV demon- 

 strate this fact, the experiment differing from that summarized in Table 

 III only in the use of sandy-loam soil instead of the heavy Yolo clay loam 

 and in the fact that a parallel experiment was run at the same time in 

 which some of the treated seed was kept in a box in the laboratory and 

 a sample was germinated in blotters after drying for periods correspond- 

 ing to those in the soil experiment (Pi. 38, A). 



Table IV.- 



-Perceniage of germination of Little Club wheat treated with formaldehyde 

 and dried, both in the soil and in the air 



Length of drying period. 



Sown in dry soil. 



o. 1 per 

 cent for- 

 maldehyde 

 solution. 



o. 2 per 

 cent for- 

 maldehyde 

 solution. 



Control, 

 dipped 

 in water. 



Dried in the air and germinated 

 in blotters. 



o- 1 per 

 cent for- 

 maldehyde 

 solution. 



o. 2 per 

 cent for- 

 maldehyde 

 solution. 



Control, 



dfpped in 



water. 



Days 



O 



2 



5 



7 



10 



14 



20 



30 



IOO 



84 

 84 

 80 



86 



74 

 88 

 62 



92 

 68 

 66 

 60 

 4 S 

 34 

 44 



90 

 84 

 86 

 90 

 62 

 80 



60 

 66 

 So 

 52 



54 

 44 



96 



100 



IOO 

 IOO 



96 

 96 

 96 

 96 



In none of the experiments summarized in Tables I to IV was there 

 any injury to seed germinated at once after the dip into either 0.1 per 

 cent or 0.2 per cent formaldehyde. This fact is not in agreement with 

 results reported by many experimenters. Stewart and Stephens (16), 

 for instance, found that an immersion of 10 minutes in a 1 to 40 solution 

 (0.1 per cent) caused almost a 50 per cent loss. Kiessling (9), for ex- 

 ample, notes the great variation in the results reported on the effect of 

 formaldehyde on germination of seed. He concludes from the work 

 of others and from his own experiments that formaldehyde produces a 

 serious effect on the seed, the degree of injury depending on the sensi- 

 tiveness of the different varieties and the condition of the sample. None 

 of the wheat varieties tested in this laboratory (Little Club, Early Baart, 

 Marquis, Defiance, Sonora, and White Australian) was ever found to be 

 injured in the least by the recommended treatment, or by one twice as 

 strong, whether germinated in blotters or in the soil, so long as it was 

 sown immediately after treatment. Not only will the seed be uninjured 

 by the usual 20-minute exposure to a 0.1 per cent solution but it will 



