RESISTANCE COMPONENTS IN BURDEKIN SUGARCANE VARIETIES TO DAMAGE BY GREYBACK CANEGRUBS

CURRENT control strategies for greyback canegrub (Dermolepida albohirtum) are integrated in the GrubPlan program. Grubplan does not include a plantresistance component such as tolerance, antibiosis or antixenosis. In field trials in the Burdekin region, we created differential populations of greyback canegrubs within commercial varieties to determine levels of canegrub tolerance. Our results did not confirm the antixenosis hypothesis that crop height influences oviposition by beetles. The majority of varieties had similar levels of tolerance to canegrub damage for cane yield and sugar yield. There was evidence that Q183A and Q208A were more resistant to grub infestation. Q183A demonstrated tolerance mechanisms including less proneness to stool tipping and vigorous ratoon shoot production. The greater resistance of Q208A was attributed to either antibiosis or antixenosis, although further research is required to determine which of these resistance components are present with Q208A.