2l6 



Journal of Agricultural Research 



Vol. XX, No. 3 



Table II. — Percentage of germination in potted soil of wheat treated with o.i per cent 

 formaldehyde and stored for various periods 



Treatment and storage. 



Stored in refrigerator at io° C: 



Treated, stored dry 



Control, stored dry 



Treated, stored damp 



Control, stored damp 



Stored in greenhouse ati5°to35°C 



Treated, stored dry 



Control, stored dry 



Treated, stored damp 



Control, stored damp 



Stored 56 

 days. 



18 

 IOO 



090 

 o 7 6 



74 



98 



100 



"82 



°The germination of these samples is lowered by the development of molds in the jars. As will be 

 reported in a subsequent paper, saprophytic fungi attack stored wheat whenever the humidity is 70 per 

 cent or more, the treated seeds being attacked more slowly because of the slight protection afforded by the 

 formaldehyde. 



After it had been determined that wheat stored and allowed to dry 

 after treatment was seriously injured, the next question which arose 

 was whether the same injury would be produced if seed sown immedi- 

 ately after treatment in dry soil remained there for some time before 

 sufficient rain fell to dampen the soil and induce germination. In dry 

 regions wheat often lies in the soil for weeks before germinating. To 

 duplicate these conditions, seed was treated in the usual manner with 

 a 0.1 per cent solution of formaldehyde and sown, 50 seeds in a pot, in 

 air-dry soil. On one series, a 0.2 per cent solution was used to show 

 more strikingly the cumulative nature of the injury. One pot of each, 

 with a control of seed treated similarly with water, was watered after 

 predetermined intervals such that the first pot was watered and started 

 to germinate immediately after planting while the last one remained 

 dry for a month. The results of the experiments with wheat are given 

 in Tables III and IV. 



Table III. — Percentage of germination of Little Club wheat after lying in dry soil ( Yolo 

 clay loam) following treatment with 0.1 per cent formaldehyde solution 



The data in Table III indicate that it is not safe to treat wheat with 

 formaldehyde, even when the strength of solution is as weak as 0.1 pei 

 cent, if the seed must be sown in very dry soil without certainty of rain 

 within a few days. 1 Besides a lower percentage of germination, the ger- 



1 Field reports are found to be in agreement with these laboratory tests. The hitherto unexplainable 

 poor stands of wheat from treated seed obtained by the farmers of the dry regions of California can now be 

 safely attributed to the fact that the seed lay in the dry soil for some time before rain. 



