92 DISEASES OF TROPICAL PLANTS c* 



land, thus removing the greater part of the disease 

 excepting in the old stubble. The lime should then 

 be applied along the rows so as to reach the greater 

 part of the affected plants. This treatment will also 

 be beneficial in combating other fungi. 



An Ithypliallus has been reported on the sugar-cane 

 in Java, and stinkhorns are found in- the cane-fields of 

 Louisiana, bufc their economic importance is as yet 

 unknown. 



Marasmius. Probably the most widespread of the 

 root diseases is due to various species of fungus known 

 as Marasmius. When this disease attacks the cane 

 the growth is retarded and the stools are weak in both 

 size and number of canes. However, many affected 

 stools are found which contain some dwarfed canes, and 

 others which show no indications whatever of the 

 disease. The leaf-sheaths when dead do not fall but 

 adhere firmly to the canes, and when pulled apart they 

 are found to be cemented and matted together by a 

 mass of whitish mycelium. The canes are light in 

 weight and can be pulled with ease because of the lack 

 of roots. When cut open in the early stages of this 

 disease the fibre-vascular bundles are reddish, and later 

 numerous cavities are formed which contain the 

 mycelium of the fungus. The roots are also covered 

 with mycelium of the same character. 



The organisms which cause this disease belong to the 

 toadstools or mushrooms, which constitute a group of 

 the higher fungi (see page 65). They are saprophytic 

 on the dead canes and parasitic on the living plants. 

 The most common method of distribution is from plant 

 to plant through the soil, or from the dead and decayed 

 parts by the growth of the mycelium. However, when 

 the climatic conditions are favourable the fruiting bodies 

 are formed. They appear as small, somewhat spherical 

 masses of mycelium, which later spread out into the 

 characteristic toadstool form, on the underside of which 

 are the gills bearing the spores. They are usually 

 about f inch in diameter, but may be larger. 



