5IO 



77ie Ohio Naturalist. 



[Vol. VI, No. 6, 



Seed treatment. — Many experiments in seed treatment by im- 

 mersion were carried on during 1904 and 1905, but all proved un- 

 successful. The presence of the mycelium and spores within 

 the seed, has, so far, rendered treatment impossible, since any 

 solution strong enough to kill the fungus, also kills the pea germ. 

 In fact, the fungus is the less susceptible of the two. Still it 

 was hoped to kill such spores as might be merely adhering to the 

 outer seed coat of the peas and thereby increase the per cent, of 

 germination. The chief chemicals used were formalin and mer- 

 curic chloride. These were used in several strengths and for 

 various lengths of time. The seed was then planted in soil (in 

 the greenhouse) or put into a seed germinator. The results, for 

 the most part, were not only unsuccessful, but negative. Liquid 

 treatment, especially when the seed was immersed for a consid- 

 erable period, seems to increase the bacterial rot'" which is also 

 responsible for the failure of some of the seeds to germinate. 

 Direct immersion in hot water as well as immersing in hot water 

 after soaking, was tried by Krueger, with the result that the 

 vitality of the seed was injured, while the fungus was not. Dry 

 heat was also applied with similar results. Though Krueger 

 found seed treatment with Bordeaux mixture ineffective, exper- 

 iments carried on by the writer during the present season, 

 showed a slight increase in germination over check plots, when 

 seed was soaked for an hour in water rolled in Bordeaux dust 

 and immediately planted. The following table gives the aver- 

 age results obtained by this treatment. The figures show the 

 number of grams produced from one foot of row; also the gain 

 or loss in per cent. The peas were drilled in rows three feet 

 apart and not sprayed: 



TABLE I. 



* No late planting. 



The result of tying up vines, of spraying with Bordeaux and 

 of omitting the last spraying, is shown in the following table. 



The per cent, of gain or loss of sprayed over unsprayed, is 

 computed for the early planting only, as the late crop of un- 

 sprayed was planted somewhat later than late planting where 

 spraying was done. Moreover, the almost complete failure was 

 due, in large part, to powdery mildew, which failed to develop in 



10. Halsted, Failure of Pea Seed to Grow. N. J. Rept., 1893. pp. 359-362. 



