Dear Fellow Chestnut Grower,

As you would be well aware chestnut internal rots were a major problem last year, with some consignments containing well over 50% of rotten nuts. This problem negatively impacted upon consumer confidence and contributed to record low prices.  If we are to have a viable industry in Australia this problem must be addressed.

In response to this, the CGA has formed an Internal Rot Committee to look at what can be done about the problem. The Rot Committee has reviewed past and recent research and sought views from researchers and people close to the problem. As a result the Rot Committee has formulated some plans. Basically it is felt that the most important, immediate solution is to stop rotten nuts reaching consumers. The only way to do this is for every grower to be active in preventing affected nuts from leaving his/her property. 

To this end we have produced a “Best Practice” sheet that can be kept in a prominent place for easy referral. These procedures will help minimize the incidence of the disease, and if all cutting guidelines are diligently observed by all growers, rotten nuts will not reach the market place.

The CGA at last years strategic planning meeting resolved to recommend to the industry that acceptable rot levels in the marketplace should be 5% or below. For lower grade markets such as Paddy’s Markets, this figure should be 5% - 10%.

In discussions held with most agents and some retailers, most have strongly indicated that these levels are far too high, venturing to say that 0% - 1% would be desirable. The Rot Committee agrees that 5% - 10% levels of rotten nuts are too high. If a grower can detect 5% rot before sending nuts to market by the time they reach the consumer the levels could be much higher.

The Rot Committee has therefore recommended to the CGA that priority should be given to establishing a research project, looking at practical management methods to minimize rot on properties, as well as a study of the conditions necessary for infection. This would assist in making predictions of rot levels prior to the commencement of harvest.

We have also recommended that this project should include studies as to how far the disease spores will travel.  Research work undertaken by David Ogilvy and Harvey Smith has shown that rot spores are released from the previous years burrs when conditions are suitable (ie. wet, warm weather during flowering). Obviously ft is therefore not much use to have individual growers being diligent about orchard hygiene, if the disease spores are potentially going to blow in across the neighbour’s fence.

It is imperative that all growers take personal responsibility to ensure that rotten chestnuts do not leave their property. To do otherwise will result in a loss of reputation to the grower and the possibility of rejection of the consignment by the agent. Consignment of rotten nuts sold by agents cause grave damage to the reputation of the industry and sustained low prices for all chestnut growers.

If you have any ideas or feedback relating to internal rot in chestnuts, please contact the Chestnut Rot Committee at:

227 Mt Stanley Rd, Stanley, Vic. 3747 or phone: 03 5728 6526.

The Rot Committee will keep you informed of any developments.

Wishing you all a successful (and rot free) chestnut harvest!

The Rot Committee: Joe Rinaudo (Chair), Peter Guest & David Mcintyre