TROPO's Organic Info Library

Promising trials for anti-anthracnose sprays

A very successfull meeting was arranged by TROPO for the release of the trial data compiled by the CSIRO's Dr. Anna Williamson. The 70-80 interested people who attended the meeting were keen to further the research and push for registration.

Dr. Williamsons' research has mostly been aimed at finding more sustainable treatments of pest and disease problems. The three tested sprays were trialed on avocados looking at the effect of the sprays on anthracnose and stem end rot.

All the sprays proved more effective than the currently used sprays (copper and sportak).

At the same time, Dr. Williamson has been looking at the effect on soil organisms of the copper sprays. Some orchards that have been spraying the recommended copper program are showing dangerous levels of copper. They also are missing several vital fungi groups that are usually found in healthy soil. This could clear up the mystery of the lack of worms in avocado orchards but mainly points to the need for more sustainable fungistats.

Dr. Williamson has only been looking at avocados but is convinced that the sprays will be equally as effective on other crops like - mangoes, macadamias , bananas , blueberries and strawberries. Until further tests have been executed it won't be known what effect the sprays will have on what crops.

Two of the sprays consist of microorganisms taken from food products and the third spray is a form of Sodium Silicate. The microorganisms are grown in vats like yoghurt.

A problem exists because of the cheapness of the sprays. In order to get Australian registration they have to undergo years of tests costing millions of dollars. Chemical companies can afford to pay these costs because they recoup the costs from sales. These sprays are unlikely to be profitable given that the growers can "grow their own". This means noone is likely to pay the money to get them registered.

Until they are registered it remains illegal to spray them on food crops. All attempts to get the government to pick up the tab have failed. The next move is to try to get the individual industries to combine and jointly fund the remaining research and registration costs.

The meeting was arranged by TROPO in order to bring the industries together for this purpose. We effectively have united the mango macadamia and nursery industries with some avocado members in order to get the sprays registered.

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