Biomin Copper gave excellent defoliation at 95% after one application
Copper Oxychloride is a very expensive product since it did not defoliate the trees; however, growers who initially compare product prices would choose Copper Oxychloride over Biomin Copper as it appears cheaper.
It is important to never choose a product on the price of a container alone, application rate and the number of applications plus the effectiveness should always be considered.
The use of Copper Oxychloride based on price would be considered false economy since the aim of applying coppers at the end of the season to defoliate stone fruit trees is to alleviate the spread of organisms causing Bacterial Blast infection through susceptible leaf scar wounds.
Since Copper Oxychloride was not effective at giving appropriate defoliation levels further applications will be required. Copper oxychloride is a heavy metal that contaminates soil and kills beneficial organisms whilst Biomin Copper is a systemic copper that leaves no residue, enters the plant and is used nutritionally without increasing soil heavy metal levels.
There is an added potential issue of residue contamination to the meat of grazing sheep after a Copper oxychloride application.