Indiana Plant Diseases, 1921 183 



Brown rot, caused by Sclerotinia cinerea, was found in Knox 

 County, June 28, on many wounded fruits of an early variety. The 

 fungus was sporulating abundantly at that time. Twig cankers of 

 scab, caused by Cladosporiu'ni carpophilitm, were sent in from Dubois 

 and Greene counties and twig infection was noted in Lawrence, Tippe- 

 canoe and Knox counties. Burkholder has found abundant evidence 

 that scab is brought into Indiana on southern-grown nursery stock. 

 A consignment of nursery stock received in Posey County in March 

 was very heavily infested with scab cankers. The fact that certain 

 orchards have the scab disease present and others do not may be ex- 

 plained by the presence or absence of the disease on the original nursery 

 stock. The same condition holds true for black spot and the explana- 

 tion may be the same. 



Root rot caused by Ao'viillaria mellea is still present in the orchard 

 in Brown County where it was recorded in 1919, and along with other 

 types of root rot is a serious source of loss in this orchard. Burkholder 

 reported that the root rot situation among peaches very closely parallels 

 that among apples in that the trouble occurs wherever peaches are 

 planted on newly cleared land in the area embracing Brown, Monroe, 

 Greene, Martin, Orange, Lawrence and Jackson counties; and over one- 

 fourth of the peach trees in the state are grown in this area. How- 

 ever, it is not likely that this trouble is all due to the fungus named 

 above. On 1921 twigs the fly speck fungus (Leptothyriuni pomi) and 

 an occasional colony of sooty blotch (Gloeodes poviigena) were noted 

 in Knox County on October 21. Mains reports that the aecial stage of 

 the rust, Puccinia pmni-spinosae, is annually prevalent on Thalictruvi 

 dioicum near Lafayette, but no telial stage on Prunus species has been 

 found. 



Pear. — Fire blight, due to Bacillus amylovorus, was noted near 

 Indianapolis in May, near Goshen in the fall, and was reported from 

 Hamilton County. In general, fire blight was not severe this season. 

 Black rot due to Physalospoi-a cydoniae and sooty blotch {Gloeodes 

 pomigena) were noted on pears in the market at Goshen. Frost injury 

 ruined the crop in southern Indiana. 



Pepper.— Mosaic was very prevalent in the Indianapolis market 

 gardens and was noted at Lafayette. Conspicuous mottling and "pock- 

 marks" on the fruit were caused by this disease. Sunscald of the fruits 

 was found very destructive in the market gardens on July 12. Ken- 

 drick" found Pliytophthora terrestris causing a rot of peppers at 

 Lafayette. 



Plum. — Black knot, caused by Plowrightia 'morhosa, became con- 

 spicuous in a number of localities this season. It was noted in Miami 

 County and was reported from Marshall, Clinton, Randolph, Hancock, 

 Marion, Monroe, Franklin and Scott counties. Brown rot of the fruit 

 caused by SclaroHnia cinerea, was sent in from Marion County. Speci- 

 mens of plum pockets caused by Exoascus pruni were also received this 

 season. Frost injury prevented the set of fruit in southern Indiana. 



Potato. — Owing probably to the abatement of the hot weather and 

 the abundant rainfall in August, Fusarium wilt of potatoes was not as 



* See footnote under eggplant. 



