87 



Soft Rot of the Iris Rhizome 



Further studies were made on this disease of the iris by Dr. 

 L. Gordon Utter. The prevalence of the soft rot among the 

 bearded iris was considerably less than that noted during the 

 previous years. Further tests were made with various chemicals 

 with a view to controlling the rot-producing bacteria, either on 

 the rhizomes or in the soil. Infection of the iris rhizomes was 

 not prevented by dipping them in solutions of bichloride of mer- 

 cury, potassium permanganate, semesan. yellow mercuric oxide, 

 or dusting with Cupro Jabonite, red copper oxide, Porno Green, 

 or lead arsenate, prior to planting. Bichloride of mercury, 

 semesan, and yellow mercuric oxide solutions were used to treat 

 the soil before planting the iris, but did not protect them from in- 

 fection later. Poor control was also obtained with chloropicrin, 

 commonly known as tear gas, when it was used as a soil treatment. 

 The percentage of rot among iris planted in untreated soil was no 

 greater than that among iris planted in the treated plots. 



Graduatk Students and Independent Investigators 

 Enrolled Durixc; 1940 



Prof. Laura A. Kolk, Biology Department, Brooklyn College, 

 has used our laboratory facilities for studies on the germination of 

 several grass smuts collected in (he vicinity of New York City. 

 She also carried out some inoculation experiments on plants grown 

 to maturity in the experimental field. 



Mr. Arthur Davidofr and Miss Jeanne P. Walther, graduate 

 students in New York University, enrolled for the research course 

 in mycology and pathology. 



Chestnut Breeding Work in 1940 * 



I i V A RT H I " R I 1 V K \ [OL'NT Gr A V E S 



The problem which we are working on is how to develop a 

 chestnut tree of a tall, straight-growing sort suitable for timber 

 and at the same time resistant to chestnut blight. 



*A more detailed account will be published in a forthcoming issue of the 

 Bulletin of tbe Torrev Botanical Club. 



