322 BULLETIN No. 189 [June, 



COLEUS, Coleus sp. 



In November, 1912, cuttings of coleus began to damp off in a bench 

 in the floricultural greenhouses. The variegated green varieties seemed 

 more susceptible to the fungus than the variegated red and yellow. The 

 trouble was found to be due to R. Solani. The infected cuttings showed 

 characteristic lesions on the stems at the surface of the sand. These 

 lesions were quite large and distinct, brown in color, and depressed 

 several millimeters at the center. They were generally found on one 

 side, but in some cases the whole cutting was girdled. Practically all 

 the coleus cuttings in the bench damped off in this manner. 



During October, 1913, Khizoctonia was found causing a damping- 

 off of coleus seedlings planted very close in flats. About half the plants 

 damped off. 



Duggar and Stewart 32 reported a damping-off of coleus cuttings 

 in New York, caused by Rhizoctonia, similar to that observed at this 

 Station. 



CONIFEROUS SEEDLINGS 



The first case reported of damping-off of white-pine seedlings due 

 to Rhizoctonia was by Duggar and Stewart, 82 from New York. Ten 

 years later Clinton 17 mentioned the damping-off of a number of conif- 

 erous seedlings. 



Hartley, 55 who made a study of the damping-off of coniferous seed- 

 lings in the West, found that Rhizoctonia is one of several organisms 

 involved. He wrote as follows : 



' * Khizoctonia (probably Corticium vagum B. & C.), which ojuises dumping-off 

 of very young seedlings, sometimes continues to work in patches till the plants are 

 two months old or even more. On sandy soil, when seedlings from five to nine 

 weeks old are killed, the youngest and deepest parts of the roots are usually first 

 attacked. At Halsey, roots of Eocky Mountain yellow-pine seedlings about seven 

 weeks old have been attacked at points as much as eleven inches below the ground 

 surface. In many plants as old as this the older parts of the roots resist the en- 

 trance of the fungus which has rotted the younger parts and throw out new root 

 branches, so that recovery takes place without any evidence of the damage being 

 shown by the plant above ground. ' ' 



Coreopsis lanceolata 



Duggar and Stewart 82 in 1901 mentioned the fact that next to a 

 plot of sweet williams that were being killed by Rhizoctonia, were two 

 rows of Coreopsis lanceolata which were also diseased. They stated 

 that ' ' only a few plants were killed, but from many of them the lower 

 leaves had rotted away. The rot seemed to start in the base of the 

 petiole, where it came in contact with the soil. The decaying leaves 

 were overrun with Rhizoctonia." 



