848 EXPERIMENT STATION RECORD. 



spot rot on the Jonathan and possibly on other varieties, and one or more 

 causing or following storage rots. 



Jonathan fruit spot, J. B. S. Norton {Phytopathology, 3 {1913), No. 2, pp. 

 99, 100). — Attention is called to the action of gas on Jonathan and other apples 

 in storage by which injury resembling that known as Jonathan fruit spot is 

 produced. It is suggested that ammonia from the cooling apparatus iLiay be a 

 common cause of the so-called Jonathan spot. 



Studies on the water core of apple, P. J. O'Gara {Phytopathology, 3 {1913), 

 No. 2, pp. 121-128, figs. 2). — The author claims that water core is a trouble 

 which is found wherever apples are grown, being very prevalent in districts 

 where there are great ranges of temperature and relative humidity. The addi- 

 tion of water to orchards either naturally or artiflcially, when followed by 

 extremely high maximum temperatures with low humidity during hours of 

 sunshine and low temperatures vwith high humidity during the night, will 

 induce water core. It is claimed that water-cored fruits are most commonly 

 found on the terminals and on the south and southwest sides of trees, as such 

 fruits are subject to greater extremes of temperature; and that heavily pruned 

 trees or trees defoliated shortly before the ripening period begins are very 

 liable to water core if the climatic conditions are favorable to the disease. 



Under proper conditions of storage, water-cored fruit, unless badly affected, 

 will entirely recover. 



Fire blight of pear and apple, J. G. Hall ( Washington Sia. Popular Bui. 56, 

 pp. 8, figs. 4)- — A popular description is given of fire blight of pear and apple, 

 due to Bacillus amylovorus, with suggestions for its control. 



In addition to the apple and pear the (ire blight is also known to attack the 

 quince, apricot, plum, wild hawthorn, and service berry. 



The control measures recommended consist in thoroughly cutting out the 

 diseased portions of the trees. Where irrigation is practiced it is recommended 

 that the amount of water used be reduced to the smallest quantity that will 

 keep the trees in a healthy condition. 



The brown rot canker of the peach, R. A. Jehle {Phytopathology, 3 {1913), 

 No. 2, pp. 105-110, pi. 1). — During the summers of 1911 and 1912 the author 

 investigated a canker of peach trees prevalent in Niagara County, New York. 



The cankers were found on limbs of all sizes but were most prevalent on 

 those which were about 1 to 2 in. in diameter. The brown rot fungus, usually 

 referred to as Sclerotinia fructigena, was found to be the cause of the cankers 

 on the trees. At first the regions appear as slight depressions but soon become 

 open wounds with copious gum flow. Later they become black and rough, and 

 increase in size from year to year. The author states that the cankers may be 

 formed by the fungus growing back from a brown rotted fruit through the 

 fruit spur into the limb, but infection of the blossoms is thought to be the 

 more common source of the trouble. Inoculations were made with S. fructigena 

 obtained from a number of sources, and in more than 200 instances infection 

 occurred on limbs of all ages. 



The author has under observation cultures of S. cinerea and S. fructigena 

 from Euroi>e and is comparing them with the American form. At present he is 

 of the opinion that the common form usually called 8. fructigena is in reality 

 JS. cinerea. 



A leaf disease of papaya, A. Maublanc {Lavoura; Bol. Soc. Nac. Agr. [Bra- 

 zil], 16 {1912), No. 10-12, pp. 20Ii-212, pis. 2; Bui. Trimest. Soc. Myeol. France, 

 29 {1913), No. 3, pp. 353-358, pi. i).— The author states that the leaves of 

 Carica papaya in Brazil, and especially in the vicinity of Rio de Janeiro, are 

 frequently attacked by a fungus which causes the formation of small spots, 



