290 Bulletin 255. 



appearance of this stage of the disease. The spots or cankers are black 

 with reddish or yellowish margins. Most growers are also familiar 

 with the appearance of the disease on the seed itself, especially on the 

 white beans where it makes rusty red spots of different sizes, sometimes 

 involving nearly the entire seed, though ordinarily only producing a 

 slight discoloration on one side. (Cover.) The disease enters the seed 

 by way of the pod, the fungus penetrating from the outside into the young 

 and tender seed. This is very well shown in Fig. 218. The cankered 

 pod has been carefully dissected away, showing brown spot 

 on the bean just underneath. When the diseased seeds 

 are planted in the soil, and first come through the ground 

 they are sure to show the small black cankers on the 

 cotyledons or seed leaves (Fig. 219) and a little later on 

 the stems. Fig. 220. Growers seldom recognize the disease 

 ^^^ * i on the seedlings as that with which they are familiar on 

 ■4j||P the pods and beans. Many of them have observed the 



blackened stubs of badly diseased seedlings, and have 

 thought the injury due to insects of some kind. Where 

 badly diseased seed is planted the loss from diseased seed- 

 lings is at times quite heavy. 



History and economic importance of the disease in this 

 state. — Many growers are inclined to the belief that this is 

 a new disease that became really destructive for the first 



T, on- time during 1006. As a matter of fact, it has long been 



Fig. 2 18. — Dis- by > & 



eased pod dis-known in this State and was very well described and 

 iw^^^'I'/z/^Sr-^Sured by Professor Beach of the Geneva Station in Bulletin 

 eased bean 48, published in 1892. At that time the disease was so 

 within. severe in the bean -growing regions of the State as to seri- 



ously threaten the industry. Like most other fungous diseases the 

 bean anthracnose has its epidemic periods. Such a period reached 

 maximum severity in the season of 1906. For three or four years 

 previous to this time the writer had observed the gradual increase 

 of this disease in the bean fields which he had occasion to visit 

 about the State. The epidemic period for this disease, as well as for 

 many others, follows very closely the periodic variations of weather 

 conditions. It will be recalled that the season of 1906 w^as a very 

 rainy one, particularly at the time when the beans were making very 

 rapid growth in the spring, and also at the time when the pods were 

 forming. The three or four years preceding this time had been increas- 

 ingly rainy during the growing period. The gradual increase of the 

 anthracnpse thus followed directly the increasing raininess of the seasons. 



