70 TBINIDAD AND TOBAGO BULLETIN. [XVIIL S, 



SUGAR-CANE VARIETIES AND FROGHOPPER 

 BLIGHT IN TRINIDAD. 



Ey C. B. Williams, M.A., F.E.S., 



Entomolog'Sj in Charge of Froghopper Investigations. 



In the course of my investigations into the complex association of 

 diseases known in Trinidad as '• Blight " or " Froghopper Blight," the 

 question has often been raised as to the possibility of reducing the damage 

 by findmg a variety of cane which is immune or resistant to the disease. 



Such a method is obviously of great importance if it can be carried 

 out and for three years I have been collecting notes and observations 

 on the resistance of the different varieties grown in Trinidad during 

 the last ten years, to see if any of them have claims to resistance which 

 can be justified by accurate observations. 



The summaries of results given below are based (1) on my own 

 observations in the field, (2) on the replies sent in by the planters in 

 1912 to a circular sent out asking for areas and varieties of cane 

 damaged in that year, (3) on replies to a somewhat similar circular 

 which I sent out at the beginning of 1918, (4) on various published 

 records. 



The particulars given below for over fifty varieties of cane, will serve 

 not only as a basis for discussion as to relative resistance, but may also, 

 in the future, be a guide to the varieties of cane at present in cultivation 

 in the island. With this in view short notes on the appearance of 

 each variety have been added when these could be obtained. 



Work has been started on a study of the root system? of the more 

 generally grown varieties on various soils to see if the depth of rooting 

 has any effect on the resistance of the variety to damage by Froghopper 

 and root disease, but sufficient results have not yet been obtained to 

 enable any reliable conclusion to be drawn. 



The following sugar-cane planters and authorities, are referred to 

 throughout, by their initials and this opportunity is taken to express 

 my thanks for their co-operation : — 



A.B. ...A. Bruce, Manager of Camden, Perseverance and 



Exchange Estates. 

 A.D.L. ...A. D.Lyder, late Manager of PJein Palais Estate, 



Usine Ste. Madeleine. 

 A.M. McC. ...A. M. McCulloch, Manager of Petit Morne Estate, 



Usine Ste. Madeleine. 

 A.R. ...A. Robertson, Manager of Union Hall Estate group, 



Usine Ste. Madeleine. 

 A.R.L. de B. ..A. R. L. de Bary, Manager of Bronte Estate. 

 C.A.F. ...C. A. Forster, Manager of Buenlntento, Malgretout, 



Friendship group (Tennants and Usine Ste. 

 Madeleine). 

 C.J.B. ...C. J. Barrilleaux, late Superintendent Mechanical Cul- 



tivation, Waterloo Estate. 

 C.C. ...C. Connell, Manager, Esperanza Estate. 



