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The Philippine Journal of Science 



observed, but in later stages at first minute, raised black specks 

 are produced under the surface at the nodes and internodes. 

 These spots then burst open, exposing a mass of black spores. 

 Under favorable conditions the ruptured black spots produce 

 curved, mucilaginous, threadlike masses of spores, from 1 to 4 

 millimeters in length. At first the interior of diseased canes 

 may be reddened; later it is browned. 



Frequently only injured tips of stalks become infected. These 

 diseased tips shrivel up and produce the characteristic spore 

 formation. Secondary shoots often arise below the diseased 

 tip, producing a much-branched cane (Plate XVII, fig. 2). 



Causal organism. — The hair- 

 like strands are made up of 

 thousands of one-celled, elong- 

 ated olivaceous spores (fig. 30). 

 No ascigerous stage has been 

 observed. 



Control. — The chief control 

 consists in proper cultural meth- 

 ods, which will produce a 

 healthy vigorously growing 

 cane that will withstand disease. 

 As far as possible both mecha- 

 nical and insect injuries should 

 be avoided. Only cuttings from healthy plants should be used. 

 In severe cases of infection the cuttings should be disinfected 

 by dipping in Bordeaux mixture before planting. All diseased 

 cane should be collected and burned, since the fungus lives 

 readily as a saprophyte and produces millions of spores to re- 

 infect the newly planted cane. 



ROOT disease: dictyophora phalloidea desvaux 



Symptoms. — Stinkhorns have been observed growing at the 

 base of plants or on the roots. This fungus is not common 

 and is chiefly found during the rainy season. Little damage 

 is done. 



ROOT disease: marasmius 



Symptoms. — A species of the fungus Marasmius has been 

 observed growing from the roots near the base of plants and 

 also as a saprophyte on the lower portion of stems. The disease 

 is more abundant during the rainy season. Little damage is 

 done. Small whitish spore-bearing bodies of the family Agari- 

 caceae are produced on infected portions. 



Fro. 30. Melamconium sacchari Massee. o, 

 mass of conidia, composing 

 hairlike strand (X 300) ; b, 

 conidia (X 900). 



