The effect of ripeners on the CCS of 47 sugarcane varieties in the Burdekin

There is little information about the response of cunent Australian sugarcane varieties to ripeners commonly used overseas. Two experiments in the Burdekin examined the response of 47 sugarcane varieties to five ripener treatments: Ethrel plus Fusilade (E+F), Fusilade alone (applied at two rates), Verdict and glyphosate. There were generally positive responses in CCS to both glyphosate and E+F eight weeks after application, and varieties differed in their degree of response. There was nO significant response to Fusilade alone at a lower rate or Verdict. The glyphosate treatment significantly increased the CCS of 20 varieties, some by over three units and E+F significantly increased the CCS of 15 varieties. In another experiment, Fusilade applied at a higher rate significantly increased the CCS of all varieties tested three weeks after application but not 15 weeks after application. At this time, Fusilade reduced the CCS of three varieties, and generally had a negative effect on cane and sugar yield. The study showed that glyphosate and E+F can significantly increase the CCS of some economically important varieties at the start of the harvest season.