26 U. S. DEPARTMENT OF AGRICULTURE. 



BEAN: RUSSET. 



Cause : Unknown. Non-parasitic. 



Russet is a rather prevalent chestnut-brown surface dis- 

 coloration of green-pod and occasionally wax-pod beans. 

 The discolored areas are of various shapes and sizes, some- 

 times involving nearly all of the pod. The affected tissue 

 is firm and sound, and is not at all sunken. The discolora- 

 tion is due to the death of the three or four outer layers of 

 cells. 



This disease seems to appear in beans that have been in 

 transit or storage for some time, and is probably not of field 

 origin. Russet is common in Florida beans in the northern 

 markets. It is objectionable because of the injury to the 

 appearance of affected stock. 



No control is known. 



BEAN: SUN-SCALD. 



Cause : Exposure to the hot sun. 



This injury first shows up on the exposed side of the pod 

 as minute brown or reddish parallel streaks, which enlarge 

 and merge to form brown or reddish areas of varying size. 

 Sun-scald is not easily distinguished from bacterial spot, but 

 is more likely to be limited to one side of the pod, and lacks 

 the greasy exudate which often is present on blight lesions. 



Sun-scald is due to exposure to the sun, and does not 

 occur where the pods are shaded. 



Ref. (41). 



LIMA BEAN: POD BLIGHT. 



Cause: A fungus (Diaporthe phaseolorum). 



In the early stages, this disease is characterized by cir- 

 cular to semi-circular spots of darkened tissue. Later the 

 affected tissue becomes studded with minute, gray eleva- 

 tions. These elevations soon break the skin of the pod, and 

 emerge as black pustules, the fruiting bodies, or pycnidia, 

 of the fungus. The pycnidia may be arranged concentri- 

 cally or in chain-like fashion. In advanced stages, the entire 

 pod may become diseased and covered with pycnidia. 



Pod blight has been reported only in the Northern Atlan- 

 tic States, and is not common. Infection takes place in the 

 field, and the disease may develop and progress in transit. 



Pod blight can be controlled by seed selection and disin- 

 fection and by spraying in the field. It is advisable to sort 

 out and not market diseased pods. 



Ref. (25). 



BEAN: RHIZOPUS ROT. 



(See Rhizopus Rot). 



BEAN: SLIMY SOFT ROT; BACTERIAL ROT. 



(See Slimy Soft Rot) . 



