THE PESTS AND DISEASES OF THE CANE i6i 



Cane W tit. Cephalosporium sacchari (Butler). — Effuse, white, hyphae creeping, 

 sparsely septate, 3-5 microns in diameter ; conidiophores continuous, simple furcate 

 or verticillate, above obtuse, at the middle or toward the base widened , 6-30 microns 

 long, 3-4 wide ; conidia numerous arising in succession at the apex of the branches 

 and collected in a head but easily separating, hyaline, ovoid or oblong ellipsoid, con- 

 tinuous, 4-12 X 2-3 microns. 



This disease, which was first described in India by Butler, duphcates 

 that described above in its life history and mode of attack. The macroscopic 

 appearance of the lesion differs from that of red rot in producing; a diffuse 

 purple discoloration with bright red patches, turning when older to an 

 earthy brown. It has also been reported from Natal, Barbados and Nevis. 



Render sonina sacchari (Butler). — Stromatibus cortice innatis demum erupen- 

 tibus sub-globoso conicis 1-2 m.m. diam. atris, intus i-pluri-locularibus ; loculis irregu- 

 laribus subinde incompletis vel inter se communicantibus, ostiolis saepe confluentibus ; 

 contextu brunneo, minute parenchymatico ; basidiis ramoso-fasciculatis, hyalinis ; 

 sporulis dimorphis, aliis fuligineis, rectis vel curvulis, ellipsoideis vel elongatis, utrinque 

 obtusis, continuis vel 1-2 septatia 15-24X3*75-5 pt-, aliis hyalinis, filiformis, rectis vel 

 flexuosis, pluriguttulatis, 20—60x0-6-2 \Jl. 



This disease is reported from India by Butler. In mode of attack it is 

 similar to the two diseases noted above. 



Pine Apple Disease.^^ Thielaviopsis paradoxa [de Seynes Hoh.) — Hyphse steriles 

 hyalinae vel pallide fuscae, septatae. Hyphae fertiles septatae non ramosge. Macro- 

 conidia ovata, fusca, catenulata, mox secedentia. Microconidia cylindracea vel 

 bacillaria, hyalina, in interiore hypharum catenulatim 

 generata et mox ex apice exsilientia. Macroconidia 16 — 

 19X10-12, m.icroconidia 10-15 x 3* 5-5, in interiore hy- 

 pharum 100—200 microns long. Hab. in culmis, fructibus, 

 foliis in insula Java.* 



X 4 



^^ 



Fig. 58 



Plate XVIII shows the appearance of sound and diseased canes, and 

 Figs. 57 and 58 that of the macro- and micro-spores. 



This fungus, which was first described by Went,^° in connection with the 

 cane, is a wound parasite, and particularly attacks and prevents the germina- 

 tion of cuttings. Diseased canes first of all become crimson red in the in- 

 terior and then turn black. At the same time they give off a peculiar odour 

 reminiscent of pineapples, which is diagnostic of the disease. In pure culture 

 the organism remains white for twenty- four hours and then turns olive green. 

 The colour is due to the macro-conidia situated in special cells at the ends of 

 short branches of the mycelium. The micro-conidia, which are rectangular 

 and colourless, occur in chains of three or more, and are also formed within 

 the top^of a hypha. This organism is parasitic on pineapples and other plants. 



Black Rot.^^ Spaeronaema adiposum (Butler). — Mycelio dense lanoso, atro, ex 

 hyphis brunneis, ramosis composito ; hyphis fertilis simplicibus, septatis, endoconidiis 

 gerentibus ; endoconidiis polymorphis, cylindraceis pyriformis vel globosis, aliis hyalinis 

 vel brunneis, le\'ibus, aliis fuscis verrucosis, 9-25 x 4- 5-18 ; peritheciis globosis, pilosis, 



♦ This fungus was first described by de Seynes in 1886 as Sporochisma paradoxum. Saccardo renamed it 

 Chalara paradoxa. Went in 1893 described it as a new species Thielaviopsis ethaceticus. Hohnel in 1904 recognised 

 the identity of the two fungi and called it Thitlaviopsis paradoxa. (v. Bull. 171, Bureau of Plant Industry, U.S. 

 Department of Agriculture.) 



M 



