28 



TECHNICAL BULLETIN 17 



When the plants became crowded in the small pots, they were trans- 

 planted to larger pots containing sterilized soil which had been inocu- 

 lated in the same way. In these pots, the plants were grown to 

 maturity. 



There was no very serious seedling blight in any of the pots. The 

 coleoptiles of most of the plants were darkened, and lesions were formed 

 on the first leaves. The seedlings in the inoculated soils were not 

 noticably smaller than those in the uninoculated, sterilized, check 

 soils. When about six weeks old the height of the plants was meas- 

 ured in order to determine the effect of the disease on growth. The 

 results are given in Table IX. In each case the table gives the average 

 height of 30 to 40 plants. 



Any differences in height of the plants in the different soils in 

 either the uninoculated or inoculated series may be considered due 

 to the influence of the soil in which they grew. As will be seen from 

 Table IX, the differences between the plants in the different types 

 of soil in the inoculated series, altho small, agree fairly well with 

 similar differences in the uninoculated series. The differences between 

 check plants and inoculated plants in the same type of soil may be 

 considered to be the result of. the disease. A comparison of the dif- 

 ferences between plants in inoculated and uninoculated soils of the 

 different types w^ill give an index of the influence of the soil type on 

 the development of the disease. 



TABLE IX 



AVERAGE HEIGHT OF WHEAT AND BARLEY PLANTS GROWN IN INOCULATED AND 

 UNINOCULATED SOILS OF VARIOUS TYPES 



* Plants were measured two days later than those in the heavy loam and in the sandy 

 loam, andso can not be compared with these. 



Judging by the height of the plants at this stage, the barley de- 

 veloped about equally well in the heavy loam and in the sand, the 

 difference in the average height being 8 millimeters in the inoculated 

 series and 7 millimeters in the check series. The increases over this 

 amount were about equal in the sandy loam and in the peat, the advan- 

 tage being slightly in favor of the latter. The difference between {he 

 height of plants in inoculated and uninoculated soils was practically the 



