320 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



to Florida and tropical America, has made its appearance in injurious 

 numbers in northern greenhouses, notably in the District of Columbia, 

 in IlHnois and Ohio. It is apparently restricted to ferns, on which it 

 feeds naturally in its occurrence in the open in the warm South, and 

 it has undoubtedly been introduced into northern greenhouses in ferns 

 from Florida. Hand-picking, though somewhat laborious, has been 

 found the best method of control. — V. G. J. 



Feterita. By H. VinaU and C. R. Ball {U.S.A. Dep. Agr., 

 Bull. 122, 1913, pp. 25-32). — Feterita is a new variety of sorghum, 

 with stems from 4 to y feet high, erect heads, and large white grains. 

 It resists drought better than any other kind of sorghum, and is 

 equal to milo in yield. — S. E. W. 



Figs, Abnormal Roots in. By F. A. Wolf {Phytopathology, iii. p. 

 115, Apr. 1913 ; figs.). — The occurrence of small roots on stems of figs 

 growing in shade and kept close and moist is described. The author 

 regards their formation as primarily a response to superabundance of 

 moisture.— i^. /. C. 



Fire Blight Disease and its Control in Nursery Stock. By 

 V. B. Stewart {U.S.A. Exp. Sin., Conn., Circ. 20 ; 1913). — Fire blight, 

 the bacterial disease caused by Bacillus amylovorus, is a native disease 

 of species of Pomeae indigenous to America. 



It occurs on a number of hosts, pear, quince, apricot, apple, plum, 

 species of Crataegus, mountain ash, service berry, and a few native 

 species of apple. Plums and apricots are seldom affected, cherries and 

 peaches not at all. The degree of susceptibility of different varie- 

 ties of the above-mentioned fruit trees is to a great extent dependent 

 upon the length of the period of active growth of the tree. Some 

 fruit trees mature their wood much earlier in the season than others, 

 and the disease is not so severe as on trees with long sappy growth. 

 All parts of the tree are attacked, flowers, fruit, twigs, spurs, branches, 

 and the disease sometimes passes down the trunk into the roots. 



Disseminating agents are bees and other insects which visit the 

 blossoms for honey and infect the nectaries, biting insects, and plant 

 lice. 



The affected parts turn brown and finally almost black, and drops 

 of viscid, milk-like substance are exuded in moist warm weather. This 

 milky substance gradually dries to the consistency of gum and turns 

 a deep brown colour. 



The general appearance of a diseased tree resembles green bush 

 partially burned, and hence the popular name " Fire Blight." The 

 organism develops rapidly during the early growing season of the 

 host plant, and winters in the diseased tissues and in the gummy 

 substance which has been exuded. 



Sprays and blight remedies have proved ineffectual, but epidemics 

 can be held in check by preventive measures and thoroughly clean 

 sanitary conditions. The elimination of some of the disseminating 



