SRA8 – Smut Update – Rob Milla
Hi All,
I am writing to inform you of an update to the Sugarcane Smut situation in the Burdekin region, with specific reference to SRA8. BPS staff detected elevated levels of smut in SRA8 at BPS approved seed cane plots in Mid August 2017 – since then, SRA pathology staff have inspected these sites and provided feedback. It should be noted that SRA8 has a smut rating of Intermediate-Susceptible, so seeing the expression of smut in this variety when conditions are favourable for smut is not unexpected. Up until August 2017, very little smut had been observed in SRA8.
The Regional Variety Committee (RVC) met on Tuesday 29th August to decide on how best to manage SRA8 with the presence of smut. Rob Magarey (SRA Pathologist) was also present, along with other senior SRA staff. Management of SRA8 was discussed at two levels – commercially planted blocks, and BPS approved seed cane plots.
Commercially planted Cane
Advice from SRA pathology staff, and supported by all members of the RVC was that growers who have planted SRA8 have no need to plough out any cane. The relatively small areas that have been planted, even if they were showing levels of smut consistent with an Intermediate-Susceptible variety, would not significantly increase pressure on the district as a whole. If growers have concerns or questions regarding SRA8 that they have planted commercially, please contact BPS staff for assistance. In terms of yield loss, it is difficult to quantify the extent as we have only observed SRA8 up to 2nd ratoon, however it is unlikely there would be significant yield losses in plant and early ratoon crops.
BPS Approved Seed Cane Plots
Varying levels of smut were found in SRA8 in BPS approved seed plots across the district. Given that smut is a wind borne fungal spore, it is not possible to protect the plots from this method of transmission, even though all other precautions to minimise risk of smut infection such as hot water treatment, clean down of equipment and planting with Sinker have been taken. Advice from pathology was that once smut infestation exceeds 1% on approved seed cane plots, then the levels of smut become unacceptable, particularly given the Burdekin situation where we have a number of major varieties (particularly Q183 and Q208) in the intermediate range for smut susceptibility. A decision was made by the RVC to plough out first ratoon cane in distribution plots where the threshold of 1% of plants infected with smut has been determined. There are two distribution plots where very low levels of smut were detected in SRA8, and these will be monitored over the next few weeks and will not be ploughed out unless they exceed the threshold. read more
