FUNGICIDE SINKER® CONTROLS PINEAPPLE SETT ROT AND SMUT—KILLING TWO BIRDS WITH ONE STONE?

SUGARCANE SMUT and pineapple sett rot are two important diseases of sugarcane in Australia. This paper summarises experiments carried out from 2007 to 2011 to study the efficacy of the fungicide Sinker® (flutriafol) for the control of sugarcane smut and pineapple sett rot. After the incursion of smut in Queensland in 2006, emergency use permits were obtained for triadimefon and propiconazole applied as a 5 min dip to protect the buds from smut infection, particularly after hot-water treatment. This 5 min dip of 1–2 tonne bundles of seed cane has some practical problems. The treatment requires a large 5,000–10,000 L tank and disposal of the waste fungicide by an environmentally acceptable method is difficult and costly. Studies on other crops suggested that the fungicide flutriafol is effective in controlling a range of diseases of grains when applied with fertiliser or as a spray in the furrow at planting. The aim of this research was to evaluate the efficacy of flutriafol (Sinker®) for the control of sugarcane smut and pineapple sett rot when applied with fertiliser or as a spray on setts at planting. Seven experiments were conducted in Bundaberg and Mackay to assess the efficacy of this fungicide against smut. Results from those experiments demonstrated that Sinker® had greater mobility into plant tissue compared to other fungicides, and was effective in controlling sugarcane smut when sprayed on the setts at planting but was not effective when applied mixed with fertiliser. The results also suggested that Sinker® could eliminate mild infection and protect the highly susceptible variety Q205A for 5–6 months. Three experiments on two varieties, Q208A and Q232A, at two locations, Bundaberg and Woodford, were established to assess the efficacy of Sinker® for controlling pineapple sett rot. Results suggested Sinker® gave superior or the same protection of setts against pineapple sett rot as Shirtan® (methoxy ethyl mercuric chloride). The results from these experiments demonstrated that the fungicide Sinker® could be an important management tool for sugarcane smut and pineapple sett rot and were the basis for an application for registration of the fungicide in sugarcane.