Ground Cover South : Ground Cover 066 January-February 2007 - South
New fumigant to secure clean grain A joint partnership between CSIRO and the GRDC is setting up alternatives to phosphine fumigation and chemicals facing environmental phase-outs (which is being phased out as part of the Montreal Protocol on Ozone Depleting Substances). It is used to fumigate buildings and equipment. These problems create opportunities for our new formulation.” Dr Ren and his colleague Colin Waterford are the key researchers behind GLO2. Mr Waterford says GLO2 can be used for on-farm grain storage because it is suitable for fumigating grain in situ and during loading. It can also be used in export shipments that need fast fumigation. “A big advantage is that it’s quick – GLO2 takes less than a day to fumigate and there is no withholding period,” he says. “That means grain can be treated one day and shipped the next.” It can be used to fumigate bulk stores, replacing methyl bromide, and for structural and equipment fumigation, replacing dichlorvos. Paul Meibusch, GRDC’s new farm products and services program manager, says the new fumigant could also be used as part of a phosphine-resistance management strategy. “Once in every four treatments, growers could potentially use GLO2 instead of phosphine, breaking insects’ resistance cycle and extending the use of phosphine in the industry.” Although laboratory tests, on-farm Stored grain GROUND COVER JANUARY -- FEBRUARY 2007 8 GLO2 ADVANTAGES n shows a high level of efficacy in eradicating major grain pests at all life stages; n acts quickly and leaves virtually no residue; n does not affect grain quality; n breaks down to compounds which occur naturally in grains; n is a liquid and can simply be poured onto grain; n is effective in both unsealed and sealed storage bins; n is safe to use in comparison to other fumigants and pesticides; n is simple to use; n does not require specialist handling skills; n has component compounds that are readily available on the market and are already in use as fumigants and food additives; n does not affect the ozone layer or contribute to greenhouse gases (nor do its breakdown products); and n is expected to have a low cost in comparison to other phosphine alternatives. CORRECTLY SEALING STORAGE The increase in on-farm storage has also prompted research into optimum storage cond- itions. Recent on-farm trials in Western Australia by Chris Newman, of the Department of Agriculture and Food, WA, and Dr Greg Daglish, of the Queensland Department of Primary Industries and Fisheries, confirmed the importance of sealed silos in achieving a commercially worthwhile result from phosphine fumigation. The GRDC-funded trials on wheat and field peas – undertaken in 89.5-cubic-metre sealed farm silos for three weeks and two weeks respectively – found large differences in phosphine concentrations at different monitoring points. Dr Daglish says this would be expected when aluminium phosphide tablets were placed in the headspace, and natural diffusion or thermal currents were relied on for gas dispersion. “In all cases, the highest concentrations were measured within the first five days, and these were recorded towards the top of the grain bulk, ” he says. However, uniform phosphine distribution appeared to be achieved between five and 10 days, except at the base-plate, where phosphine concentration was sometimes lower than at other monitoring points. The research also found that daily loss of phosphine from the airspace was estimated to be six to eight per cent for the wheat fumigations, compared with 17 per cent for the field pea fumigation. “Loss of phosphine would have been through a combination of grain sorption and leakage, ” Dr Daglish says. “All three wheat fumigations were conducted in silos that passed the pressure test standard, while the silo used to fumigate the field peas did not. It is also possible that field peas are more sorptive than wheat.” The results from these trials, which were planned to investigate phosphine fumigation of cool grain, suggest that phosphine fumigation of grain in sealed farm silos is effective against insect pests. The results also reaffirmed that the three-minute pressure standard is needed to test the sealing ability of silos and that it takes some time for fumigant to spread evenly through the silo. More fumigation trials on cool grain are planned for WA, Queensland and NSW. GRDC Research Code DAQ00098 More information: Dr Greg Daglish, 07 3896 9415, email@example.com; Chris Newman, 08 9366 2309, firstname.lastname@example.org; Dr Joanne Holloway, 02 6938 1605, email@example.com CSIRO Entomology's Dr YongLin Ren: alternative fumigants have become crucial. PHOTO: REBECCA THYER Mr Meibusch says that although the project’s main focus has been the Australian grains industry, it could have benefits for other industries such as timber and dried fruit. “We believe the product will also have a great market overseas, which would help with the product’s affordability,” he says. CSIRO and the GRDC are compiling a registration package for the new fumigant, BY MELISSA MARINO AND REBECCA THYER n In what was mostly a grim year for the grains industry in 2006, some good news has arrived in the perennial battle to control stored grain insect pests, with researchers developing an environmentally safe and easy-to-use alternative to phosphine. Phosphine has been the mainstay of insect control in stored grain since the 1950s and an important factor in Australia’s reputation for clean grain in export markets. However, the pressure has been on to find a new fumigant, as increasing numbers of insects show signs of phosphine resistance at the same time that more and more grain is being stored on-farm. Most alternatives have been progressively eliminated because of environmental flow-ons, such as residues or ozone-depleting characteristics. Over the past 10 to 15 years, CSIRO Entomology has carried out several successful GRDC projects investigating fumigant alternatives. The most promising is GLO2, the working title for a GRDC- CSIRO patented product which contains 95 per cent ethyl formate and five per cent isothiocyanide (ITC), both of which are naturally occurring chemicals. GLO2 has been formulated as a liquid fumigant, which means it can be transported in drums and sprayed directly onto grains and other products. It will vaporise in situ, but can also be vaporised prior to use if required. There are no residues to clean up and it is considered tobeasafeand effective alternative to methyl bromide, carbon disulphide and dichlorvos, as well as phosphine. CSIRO senior researcher Dr YongLin Ren says alternative fumigants have become crucial throughout the industry’s supply chain. “Two existing grain fumigants, methyl bromide and carbon disulphide, are being phased out because of health and environmental concerns, and insect pests are showing increasing resistance to phosphine, the remaining traditional fumigant,” he says. “Additionally, there are increasing health concerns over the use of dichlorvos while researching commercial opportunities. They plan to discuss the product with potential commercial partners in mid- 2007, so the product could be available to growers and others within three years. GRDC Research Code GLO200011 More information: Paul Meibusch, 02 6272 5525, firstname.lastname@example.org Dr Colin Waterford: "Grain can be treated one day and shipped the next." PHOTO: BRAD COLLIS trials and 50-tonne silo trials have already proven the product’s ability, the team must now focus on providing data to support an application for product registration. To do so, CSIRO is undertaking regionally based storage trials with all grain types to understand GLO2’s toxicology, so that label rates, environmental effects, efficacy and health and safety issues can be determined.
Ground Cover 065 November-December 2006 - South
Ground Cover 067 March-April 2007 - South