FUNGOID PESTS OF CULTIVATED PLANTS. 115 



bodies are somewhat oval, attenuated towards each end, so as to be 

 thickest in the middle, or they are of an elongatqd pear- shape, and 

 coloured brown, like the threads, but varying much in form and size. 

 Although usually consisting of only a single cell, the conidia are 

 sometimes divided by a septum towards one end into two unequal cells 

 (30 x 7-9 /u). 



The conidia germinate rapidly in water or moist air, and scab spots 

 on the fruit may be found covered with vast numbers of germinating 

 spores. The germ tubes are rather thick and coloured, with frequent 

 divisions, or septa ; sometimes the germ tubes will produce secondary 

 spores at their tips, which in turn germinate like the original spore. 

 The conidia will germinate in pure water (50 Fahr.) within eight hours. 

 It is believed that the mycelium is perennial, living in the fallen leaves 

 and twigs, and especially in the fruit, during the winter. 



It has been observed in America that the individual cells or joints of 

 the mould, under favourable conditions, will push out germ tubes and 

 develop new individuals of the species. " This method may be roughly 

 compared to reproduction by root cuttings in higher plants." 



In early spring spray thoroughly with sulphate of iron. As soon as 

 the fruit is set apply Bordeaux mixture or a modified preparation of eau 

 celeste. 



In storing fruit especial care should be taken to separate all Apples 

 which show any signs of " scab " from those which are sound and healthy, 

 and store in a dry place. 



This pest is recognised in France, Belgium, Germany, Austria, Italy, 

 North America, and Australia. 



Gard. Chron. Nov. 28, 1885, figs. 155, 156; Mass. PL Dis. 302. fig. 

 80; Sacc. Syll. iv. 1642 ; Sacc.Fun.ltal.i.l$Z\ Cooke Hdbk. No. 1747 ; 

 U.S.A. Dep. Agri. 1887, p. 341, with figs. ; Thilm. Pom. p. 15 ; Grevillea, 

 xx. p. 27 ; Tubeuf, Dis. 219, fig. ; Journ, E.H.S. sxviii. p. 292. 



Apple rot, after scab, causes serious trouble in the United States. It 

 is attributed to the common mould, Cephalothecium roseum, which has 

 always been regarded as a saprophyte in Britain. (Journ. E.H.S. xxviii. 

 p. 233 ; xxix. 1904, p. 91.) 



BITTEB ROT OF APPLE. 

 Glceosporium fructigenum (Berk.), PI. X. fig. 4. 



Under the above name a disease is known in the United States which 

 is attributed to this fungus as a cause. In this country it is rather 

 doubtful whether the fungus is the cause of disease, since it has been 

 affirmed that in most observed cases the fruits have been decayed before 

 the fungus made its appearance. Still it must be conceded that nearly 

 all the species of the genus to which it belongs are active parasites. 



The pustules are circularly arranged in a cluster of a dirty rose 

 colour, at length splitting the cuticle at the apex to discharge the 

 contents. The conidia are cylindrical, sometimes curved, rounded at the 

 ends and colourless (20-30 x 5-6 /u), produced at the tips of nearly 

 equally long hyaline threads. 



Notwithstanding that the fruit exhibits decay with us before the 

 fungus is detected it may prove to be true that such decay has been 



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