CONTROLLING BROWN ROT Prevention is better than cure
News
OSCAR VILLALTA is a plant pathologist at the Department of Economic Development , Jobs , Transport and Resources , Victoria
CONTROLLING BROWN ROT Prevention is better than cure
The best way to prevent brown rot problems is to use a multi-layered management approach that includes :
1 . Effective pre-harvest control of blossom blight and fruit brown rot ( orchard sanitation to destroy “ mummies ” from the last season ; fungicide sprays from 5 % bloom to shuck fall , as well as during immature fruit stages if disease pressure is high and when fruit is ripening , at a frequency suitable to infection risk ).
2 . Identifying dormant fruit infection shortly before harvest so as to develop a postharvest management and marketing strategy .
3 . Use of effective harvest and postharvest handling practices to reduce incidence of infection and spread . in terms of postharvest application ( e . g . Scholar ). Negotiations are continuing but , again , this emphasises the need for good control during flowering and early fruit set .
Infection by brown rot can stay dormant and undetectable right until harvest . However , decay can develop within a few days as fruit starts to ripen . Timely harvest , handling fruit carefully to avoid injuries , using clean containers to hold fruit and cooling promptly after harvest can all help reduce postharvest brown rot problems .
Effective sanitisers are essential to destroy spores of Monilinia , as well as other decay fungi , in water flumes and during postharvest washing . Sanitisers can kill spores in water and on fruit surfaces . However , they cannot control latent infections , and often do not protect wounded tissues if spores have lodged inside .
ACKNOWLEDGEMENT : This project has been funded by Horticulture Innovation Australia Ltd using the summerfruit levy and funds from the Australian Government ( SF12004 ). It has been supported by the Victorian Department of Economic Development , Jobs , Transport and Resources .
For more information , please refer to a brochure published last year on management of brown rot . This summarises the outcomes of project SF12004 , describing a Monilinia infection model which can be used to improve the timing of fungicide applications for blossom blight and brown rot of fruit . It also includes a best practice guide for managing this disease , and describes a method for identifying latent infections in fruit shortly before harvest . This brochure is available on the Summerfruit Australia website . An article in this magazine in August 2015 ( pp . 29 – 33 ) described the efficacy of fungicides used to control Monilinia infection . summerfruit . com . au august 2016 | Australian Stonefruit Grower 19