8th International conference on controlled atmosphere and fumigation in stored products

Rob Emery visited China to attend the 8th International Conference on Controlled Atmospheres and Fumigation in Stored Products (CAF) to present Australia's approach to dealing with the 2007 Khapra beetle incursion.

The CAF conference is the leading international meeting reporting on advances in research and development on gaseous treatments applied to protect cereals and other commodities in storage. Mr Emery has attended the CAF conferences since 1996 in Cyprus, California and in Brisbane where he chaired Symposium four, ‘Managing resistance in pests’ and facilitated Workshop two, ‘Pest resistance to fumigants and controlled atmospheres’. This travel will also provide an opportunity to renew contacts with Chinese researchers made during Mr Emery’s review of Australian Centre for International Agricultural Research (ACIAR) project ‘Integrating effective phosphine fumigation practices into grain storage systems in China, Vietnam and Australia’.

The CAF conference typically attracts almost 200 delegates from 27 countries providing an excellent opportunity to forge collaborative ties with industry and researchers. Previously this relationship has been with Grains research and Development Corporation (GRDC) and this conference will allow excellent exposure for the Department of Agriculture and Food, Western Australia (DAFWA) and the Cooperative Research Centre for National Plant Biosecurity (CRCNPB). The proposed presentation on the Khapra beetle eradication will demonstrate Australia’s uncompromising approach at a time when international markets are becoming increasingly sensitive to the presence of this pest in export produce and recent export bans have been imposed by China on US soybeans and Russia on Indian agricultural products. The presentation will also demonstrate and reiterate Australia’s complete freedom from Khapra beetle.

Key issues from plenary papers:

• Grain prices continue to be high as the supply is limited and the future unpredictable, due to climate change and non-food uses of grains (biofuels).
• Fumigation continues to be the foundation for protection, phosphine remains the focus and resistance is the biggest threat.
• New fumigants are not established and controlled atmosphere is still not popular.
• Many labs are being shut down or relocated especially outside China.
• China is the largest producer and consumer of grain in the world 500mt with 150-200mt held in Federal Grain Reserve. There are over 200 companies in China with storage capacity of over 100,000t.

Methyl Bromide Replacement Evening Workshop

Presentations from:

• Subi on heat treatments in general
• Shlomo Navarro about heat treatment for dry fruit
• YongLin to discuss ethyl formate
• Jonathan Banks HCN, propylene oxide and regulatory issues
• Paul Ebert to look at metabolic activators, and
• Peter Joyce the environmental impacts of alternatives.

Subi noted that to optimize heat treatments it is important to calculate when to stop, he demonstrated a Heat Treatment Calculator that works with the exact BTU based on volume. This helped to eliminate cool spots of less than 50 degrees. Noted that young T. castaneum larvae are the most tolerant followed by old larvae and Lasioderma eggs. The model predicted 100 per cent mortality of larvae in 10 hours. Trials with temperature monitoring sensors that (presumabley) communicate with each other by bluetooth and permit very sophisticated temperature profiles and predicted survival calculation.

During YongLin’s presentation Banks noted that we must have a standard resistance assay. Colin Waterford commented that we need to understand gas distribution and potential for residue problems. Shlomo Navarro has treated 7 million tonnes for Carpophilus which start in the field and then get worse in storage. He has found it not to be as good as heat treatment or methyl bromide. Vapormate works well but the CO2 can be phytotoxic.

Banks observed that HCN is very effective but people have been scared off because of perceived connection with terrorist activity. It is soluble with water and therefore only suitable for dry commodities. New Zealand, Japan and India all use HCN for quarantine purposes noting that it is especially effective against snails. The danger with some flour mills is the inadequate sealing could be a danger to neighbours. One of the professional fumigators at the workshop scoffed that there is no way they would ever use HCN because it is just far too dangerous.

During the regulator issues discussion, disappointment was expressed that regulators had not attended the conference and therefore had little understanding of fumigation requirements.