Down the rabbit hole sprayed by pesticides

Spraying poisons goes against the fundamental principles of a living earth and is unacceptable in modern society.

Unfortunately we still do it wilfully, cheerfully and without much examination. Ray Moynihan’s front page piece highlights the urgent need for the reform of Australia’s health standards and to clearly define what constitutes poison or a harmless chemical.

While state and federal governments continue to play a reactive role in banning poisons as they appear, the immediate question is why spray the maccas? The potentially harmful agent in this instance – Difenoconazole – is used for the control of husk spot in macadamias, according to the Australian Pesticides and Veterinary Medicines Authority.

So what is husk spot? It’s caused by a fungus, and is a well known serious disease, says www.tpp.uq.edu.au, a ‘research centre’ website for tropical fruit protection.

Difenoconazole is produced by a company called Syngenta Australia. Its parent US company launched the pursuit for chemical answers to organic problems in 1926, says its website.

Associate Professor Andre Drenth from QLD university has done research into fungal pathogens that cause diseases on endemic plants such as macadamia, and kindly provided The Echo some valuable insights into what the macca industry faces.

‘The industry standard for husk spot control in susceptible varieties is application of Carbendazim mixed with copper first at at the matchhead stage of development of the macadamia fruit followed by an application four weeks later.

‘Recently a new fungicide, Cabrio, which mode of action was originally derived from the natural ability of mushrooms to withstand attack by other fungi, was registered for the control of husk spot as there is a chance that Carbendazim will be phased out in the near future and is under review by the APVMA. Cabrio is a newer type of fungicide with a more specific mode of action and fewer side-effects.

‘We have conducted several laboratory and field trials with different biological control agents over the last few years.

‘Unfortunately, none of these products has lived up to claims made by their manufacturers with regards to their effectiveness in randomised trials. We continue to test new biological control agents but in general the effectiveness of control has not been good. Epidemics of fungal diseases are driven by the weather.

‘The most effective and environmentally sound way to control this disease is through breeding disease resistance into new varieties. ‘We have developed ways to screen for this disease and we are actively involved in the breeding program for this purpose. The breeding program is financed by the macadamia industry to combine good quality macadamia nuts with pest and disease resistance.

‘However, breeding is a longterm strategy and we still have many trees in the ground which need to be protected in the meantime in the most effective and safest way possible.’

Spraying – even potential poisons – originates from the need to produce high volumes of food and clear land at the most economically viable price within the guidelines of legislation. Clearly science, government and industry plan to continue to find chemical answers to an organic problem. Let’s take chemicals out of food altogether. The Cuban crisis in the 1990s showed us that human ingenuity can prevail, independent of complex food supply structures. Without even fuel for tractors they found a way. Applying better alternatives to spraying chemicals would address the bad reflection this has on the behaviour of our species.