In recent years, the production of broccoli produced for processing into frozen vegetable products has increased rapidly.
Wetting agents are usually included with disease control program to improve the coverage and uptake of protectants on waxy plant surfaces.
This 2003 poster was developed to provide industry with a better understanding of the role of these wetting agents in the control of broccoli diseases.
Most copper products have little or no surfactant activity and do not wet the florets or pre-dispose heads to head rot.
In 2002, many growers were known to apply these adjuvants at the maximum rates recommended with insecticides on broccoli crops.
However, as a result of findings in this study, high rates of these adjuvants may pre-dispose the wet florets to severe head rot and lower rates are recommended for use instead.
The minimum rates recommended on labels were shown to be as effective in wetting the florets as higher rates of the adjuvants, with lower risks to bacterial invasion.
Excessive metallic copper ions, however, may have phytotoxic effects on plant tissues and cause burning or blemishes similar to black spots on sepals of florets.
The funding of this project by McCain Foods (Australia) Pty Ltd, Simplot Australia Pty Ltd, Nufarm Australia Ltd and Horticulture Australia Limited is gratefully acknowledged.
We would like to thank the growers and field officers from Simplot Australia Pty Ltd and McCain Foods (Australia) Pty Ltd, who assisted in the project studies.
Serve-Ag Research staff who assisted in the field trials include Sarah Lamprey, Pam Cox and Diane Sward. Crop Health Services of Agriculture Victoria assisted in the species identification of fluorescent Pseudomonas.