For the last 20 to 30 years packhouse managers have only had a small number of fungicides available for controlling storage rots.
This resulted in reduced sensitivity to these fungicides and resistance problems. To add to this problem, carbendazim was removed from the market. This left a big void in post harvest options for disease control.
Practices to minimise storage rots
- Maintaining applications of broad spectrum fungicides such as Captan (or even an application of Pristine) leading up to harvest is important for protecting fruit from storage rots.
- Avoid harvesting fruit while it is wet, or soon after a rain
- Treat fruit with postharvest fungicides, preferably within 12 hours of picking if possible
- Monitor pickers—fruit going into storage needs to be handled carefully to avoid injury
- Sanitation is a priority to minimise infection from pathogenic spores. Sanitising the packhouse water and cleaning bins to remove old rotting fruit can reduce the inoculum level of post harvest diseases.
Scholar
A new fungicide, Scholar, became available last year and has performed very well. The active ingredient, fludioxonil, was discovered from a soil borne bacterium.
Scholar is in a different chemical group to the other main dipping fungicides and offers a different mode of action for controlling disease. Scholar’s attributes include:
- A new broad spectrum postharvest fungicide
- Preventative and anti-sporulant activity
- Long residual activity
- Compatible with other fungicides, DPA and sanitisers.
Scholar can be a good option for packhouses looking to preserve the efficacy of fungicides and minimise the risk of developing resistant strains.
For maximum protection of apples in post harvest storage, consider treating fruit with both Scholar and Rovral fungicides. (See Table 1 for a brief explanation of the common diseases observed in Australia and the products available for control).
See this article and Table 1 in the February 2013 Tree Fruit
