It has been suggested, and it is believed with good basis, that | 

 Odontia saccharicola is the perfect stage of Himantia stelUfera. This j 

 possibility affords a further point to be included in the above pro- j 

 posed investigations. The presence of stellate crystals in the fruit- 

 ing bodies as reported by Dr. Burt affords further evidence of such 

 a connection. 



The need of a greenhouse (a lack which has now been remedied) j 

 from w^hich wind and insects can be excluded and where moisture 

 supply and other factors can be controlled to a large extent has lieen 

 one reason preventing careful studies of root disease up to this time. 

 Pot cultures in the open have proven very disappointing, and more ] 

 often than not complete failures. i 



BOOT-KNOT {Heterodera radicicola [Greef] Miill.) * 



While not due to the work of a fungus, some mention of root- 1 



knot for the sake of completeness is desirable in a paper of this ' 

 nature. Although a considerable number of economic plants suffer 



from nematode attack in Porto Rico (75, 76) particularly some of ! 

 the vegetables, cane in so far as observed suffers but little. In one 



instance a considerable amount of infestation was found in 1915 in i 



certain fields near Juncos which were suffering from unfavorable ! 



weather conditions, and a rotting of old stools (root disease). So ■ 

 many conditions were involved that it was impossible to say as to 



whether the nematodes were playing any large part in the destruc- ! 



tion of the cane. In experimental plantings artificially infestetl hy I 



burying typical root -knot material from Colcvs, only slight infesta- i 

 tions resulted. Root-knot apparently does not tln^eaten any great 



amount of harm to cane in Porto Rico. Other species of nematodes ; 



have not been encountered. ] 



Porto Rioo. — On cane, Juncos, July 29, 1915, 2934; Rio Pie- ' 

 dras, 1917. Also collected on a wide range of other hosts, reported i 

 in other j^ublieations (75, 76). ' 



I 

 DISEASES OF THE STALK. 



THE \w,D ROT {Colleiotrichiim falcatum). 1 



The red rot or red siiuit as it is known in Java can liardly be con- 

 sidered as one of the serious cane diseases of Porto Rico, althougli 

 the fungus causing it is one of the most common forms encountered, 

 usually as a saprophyte. As a parasite it attacks the stalk and leaves 

 causing in the first instance an internal red rot, and in the second 



190 



