•4 Report op the Botanist of thh 



experiments on coating the seeid with fungicides. 



All of our experiments on the sulphur-lime treatment have 

 pointed to the importance of bringing the mixture into close con- 

 tact with the seed. While thinking over this it occurred to us to 

 try the direct application of fungicides to the seed. 



A quantity of smut-infested soil was secured and to make sure 

 that it was thoroughly impregnated with smut spores a quantity 

 of the juice of smutty onions was mixed with it. Five boxes, 

 12 inches square and 4 inches deep, were filled with this soil. 

 One box was planted with onion seed which had been dipped In 

 a 10 per ct. solution of potassium sulphide; one box with seed 

 dipped in eau grison;!^ ^ng ^qx with seed wet with water and 

 then rolled in sulphur and lime; one box with seed wet with 

 thin glue and then rolled in sulphur and lime; and the remaining 

 box with untreated seed for a check. A sixth box was filled with 

 sterilized soil and sowed with untreated seed; 200 seeds were 

 planted in each box. 



The seeds, which were first wet with thin glue and then rolled 

 in sulphur and lime, retained the sulphur and lime nicely and 

 we had high hopes of the success of thie treatment. But wheis 

 the plants came up many were found to be affected with smut, 

 and at the end of four weeks there was but one living plant in 

 all five boxes of the smutty soil. They had all died with smut; 

 while in the box of sterilized soil there was nearly a full stand of 

 healthy plants. 



Thus it appears that a coating of sulphur and lime on the seed 

 alone is not sufficient; the fungicide must be where it will come 

 in contact with the caulicle or radicle or perhaps both. 



CONCLUSIONS AND RECOMMENDATIONS. 



There seems to be no doubt that onion smut can be prevented 

 to a considerable extent, but not wholly, by the application of 

 sulphur and air-slaked lime in the drills at the time of sowing 



"For the formula of eau grlson see Lodeman, D. Q. The Spraying of 

 Plants, p. 147. MacMillan & Co., 18G6. 



