DTSEASER OF PLANTS. 847 



Potato rot, I. B. P. Evans (Traiisvuul Ayr. Jour., 7 (1908), No. 25, /tii. i!^. 

 65, III. J). — A (k>sorii»tion is {livon of potato rot due. to Xcctria solani aud the 

 statement made that larjre (luaiitities of seed i)otatoes consigned to the Trans- 

 \aal from l-'rauee and (Jermany were foinid to be affected by this fungus. 

 Kxperiments carried on at the Botanical Experiment Station, Pretoria, showed 

 tliat the disease was readily communicated through the planting of diseased 

 miters, and prwautionary measures are suggested for its control. 



The fniit spot of apples, C. Brooks (Ncic Hampshire Sta. Sci. Vontrib. 2, 

 nil. ■'i..'.i-','>(l. Ills. 7. ////.S-. .,'; liul. Torrcy Hot. Club, .i5 (lUOH), \o. 9, pp. .',23-'i5(l 

 pis. 7, //V/.s'. 2). — As a result of studies, the author repftrts two distinct fruit 

 siK)ts that occur on New Hampshire apples. 



The first, to which he gives the name fruit pit, is characterized by numerous 

 sunlven areas from 2 to G mm. in diameter on the surface of the apple. These 

 depressions are somewhat hemispherical in shape and have the appearance of 

 brni.ses. At a later stage the tissues begin to take on a brown tint, and later 

 the surface cells become dark brown. The author has been unable to detect 

 a i)itter taste in the browntnl tissue of the fruit pits. The surface spotting is 

 often acc(»nipanied by lirowuing of the tissue inmiediately surrounding the 

 va.scular bundles. The surface spots may, however, occur without the internal 

 browning, or the internal browning may be unaccompanied by any surface 

 indications. Microscopical examination of a large number of fruit pits has 

 given no indication of the presence of either bacteria or fungi, and it is believed 

 that this form of disease is not very common in New England. 



The second form of fruit six)t of apples is said to be very connnon in the 

 New Hampshire and Boston markets, often from 5() to 90 per cent of the fruit 

 lieing spotted. It occurs on almost every variety of apple, but is worst on 

 Baldwins, and the disea.se has been freipiently referred to as Baldwin spot. 

 The tlisease makes its api)earance about the middle of August, and at this 

 time one may notice spots of a deeper red color on the colored surface of the 

 apple and darker green on the lighter portions. Usually they occur at a 

 ienticel, but are sometimes covered with a smooth and apparently unbroken 

 epidermis. The reil color gradually changes to brown or black, and on the 

 green surfac«'s the sp«»ts may Itecome sunken, but the depressions are due to a 

 lack of growth and not to any shriveling of the tlesh. 



The develoitment of the spots seems to depend upon seasonal and storage 

 condltion.s. When the weather is damp and foggy during the last weeks before 

 harvesting, the s|iots on the re<l fruit surfaces develop rapidly and become 

 black and sunken before the fruit is gathered. After gathering, the spots 

 develop most rapidly on apples placed in boxes and barrels in cellar storage. 

 Wiiere the ai>ples are placed immediately in cold storage there is little or no 

 further deveio|iuient of tlie fruit spot. On withered fruit the green spots often 

 stand alxtve the surrounding portions, forming elevations that are in marked 

 contrast witli the yellow withered skin. 



The autlior has sectioue«l many hundred fruit sjtots and found a parasitic 

 fungus constantly associjited with them. By means of inoculations he has 

 deni(»nstnited that tliis fungus, tlie various <-haracteristics of wliich he describes, 

 and for which he propo.ses the name Cpliiulrusporiuin poini n. sp., is the cause 

 of tile trouble. The fungus gains entrance to the apple In July or early 

 August, and wlien it finds Its way into the intercellular spaces, obtains its 

 nourishment from the jtlant cells. It' tlic fruit is attacked Itefore the cells have 

 lost thi'ir power to respond to external stimuli, the fungus is soon iiartially 

 surrounded by a layer of brown, thick-walled cells which may serve as a 



