19.21.] Ill 



S I T G A ll . 



SUGAR CANE PESTS & DISEASES IN TRINIDAD IN 1920- 

 By C. 15. Williams, M.A., F.E.S., 



Sugar Cane Entomologist. 

 The following report gives an account of the principal diseases and 

 pests of sugar cane observed in Trinidad during 1920 and the results of 

 some experiments carried out in connection with them. In the case of 

 the Froghopper the observations are to be taken as supplementing the 

 information contained in my liciwrt on the Froglioppcr Bl'ujhtof Sugar 

 Cane in Trinidad {Memoir JSo. 1 Dept. Agr., T. d T., January, 1921), 

 and in the case of the Mosaic Disease reference should be made to 

 " The Mosaic Disease of Sugar Cane in Trinidad " (Bidl. Bept. Agr., 

 T. d- T., XIX. 1920 30-37). 



THE WEITHER DUEIXG 1920. 



The dry season set in towards the end of December, 1919 but after 

 about a month of dry weather, during which the canes stopped growing 

 more general rains occurred and the season was exceptionally mild 

 until the middle of March. In the second half of March however the 

 weather became much drier and a severe drought set in which did not 

 break until the middle of June. 



The wet season which commenced about June 15 to 20, was 

 imusually late in starting, but regular rains without floods or droughts 

 occurred during the greater part of the year, and good growing weather 

 for canes was experienced. September was unusually wet in tlie 

 northern half of the island. The " Indian Summer" was noticeable 

 but not serious in the first two weeks in October. 



THE SUGAR CANE FROGHOPPER {Tomaspir, saccharina). 



Broods at^t> Damage. 



The first brood of froghoppers was at its height about the second 

 week in August and did little damage except in the flat lands round 

 the Guaracara river and one or two isolated areas in the Naparimas. 



The second brood, about the first two weeks in October, did severe 

 damage in a number of wide-spread areas. Most of the estates in 

 the Naparimas had fields severely injured and some reported wor.-?e 

 damage than ever before. In the Couva district blight was wide-spread 

 and one estate recorded worse damage than ever before. In the north 

 damage was not severe except in a few fields at Orange Grove. 



The canes belonging to the farmers of the Usine Ste. Madeleine were 

 in general less damaged than the estate canes of the same Company 

 but large areas of farmers' canes in the Palmiste and Rambert village 

 districts were badly damaged. 



After the second brood considerable recovery set in and continued 

 till the advent of the third brood about the first week in December. 

 This brood caused severe injury in several areas not previously damaged 

 but on the whole there was less damage than was caused by the second 

 brood. 



All the broods were unusually late this year ; the second brood 

 occurring almost at the same time as the third brood of some previous 

 years. 



