46 



HOW FUKTllEU KESEAKCH MAY INOK'EASE THE EFF] 

 CIENOY OF THE CONTKOJ. OF THE CHEST- 

 NUT BAKK DISEASE. 



KY l'KOl''ESS(.U{ W. mtWAKl) JIANKIN, ContrH Uiiimsily, IUkuu, N. 1. 



Mi\ (Miaiiinaii, Ladies and Geiitleincii : Up lo (his liiiie iiivesti- 

 i;a(i()iis coiicei'iiiiig the chestiuit tree canker disease and the 

 causal fnnj'ns have not bronglit forth facts as rapidly as Ave 

 conld Avisli. It was the opinion of the conference held at Albany, 

 N. Y. last October that we did not liave facts enoni>h abont tbe 

 (lis(Nise and that scientific research was the one thing needed. To 

 emphasize this point we may consider some important phases of 

 (lie disease wliich are yet little nnderstocxi, but tlie kii()\\ ledge of 

 w hich is Innibimental to devising efficient control methods. Coii- 

 ceniing tlie means of spread of the fnngns from one tree to 

 another we have nothing except secondary evidence. Most writ- 

 ers have theorized on the different metJiods by whicli tlu; conidia 

 or snmmer spores miglit be carried from one tree to another and 

 a new infection started. . Reasoning by analogy with what is 

 known of the behavior of many fungi, snch agencies as borers, 

 birds, ants and the wind, etc., have been snggested but in no wise 

 proved to be responsible. It seems that the ascospore stage has 

 not been considered by any Avriter in the dissemiiuition of the 

 fnngns, yet this stage follows the conidia very quickly and is the 

 more abundant fruiting stage which is formed in the red or brown 

 pustules on the surface of the cankers. Under moist conditions 

 the ascospores are shot forcibly out in the air where they can be 

 caught up by the wind and carried for a considerable distance. 

 The speaker found the ascospores being shot from nuiture pus- 

 Inles during every rainy period last summer. Tliese spores ger- 

 minate readily in rain water producing a new mycelium of con- 

 siderable length in fifteen hours. The question at once arises, 

 why could not these ascospores once shot into the air be carried 

 long distances and owing to their abundance cause a large ma- 

 jority of the infection? The time of year at which new infec- 



