Kew YoiiK Agricultural Experiment Station. 93 



liwiis o-erminated in smut-free soil do not contract the disease 

 when transplanted into smut-infested soil. 



The following little experiment made by us in 1900 confirms 

 the 'results obtained by Thaxter and Sturgis. In a garden at 

 Jamaica, Long Island, where onion smut had never been known 

 to occur, we planted onion seed in eight rows each ten feet in 

 length. A quantity of smut-infested soil was brought f^'om 

 Florida, N. Y., and applied to four of the rows, as follows: 



Row 1. Smutty soil sown in the open row before sowing the 

 seed; 



Row 2. Check; 



Roic 3. Smutty soil sown in the open row after the seed was 

 sown, but before it Avas covered; 



Row 4' Check; 



Row 5. Smutty soil sown over the rows immediately after the 

 seed was covered; 



Row 6. Check; 



Row 7. Smutty soil sown over the row^s 11 days after the seed 

 was sown — just after the seedlings began to appear above the 

 surface of the soil; 



Roiv 8. Check. 



The seed was sown May 2. There was rain on the morning of 

 May 3 and again on the evening of May 8. 



In Rows 2, 4, 6, 7 and 8 none of the plants became infested 

 with smut; in Rows 1 and 3 there were very many smutty plants; 

 and in Row 5 i few smutty plants. 



The results of this experiment indicate that by the time the 

 onion seedlings reach the surface of the soil they are immune to 

 the attacks of smut. The few smutty plants in Row 5 are to be 

 accounted for by supposing that the rain of May 3 carried some 

 of the smut spores down to the germinating seeds. In the case 

 of Row 7 it is very improbable that the failure of the plants to 

 become infested was due to the lack of suitable conditions 'for 

 spore germination; because light rains fell May 13, 15, 16, 17 and 

 18; on Miiy 19 there was a heavy rain. 



