Sulfur VS Copper on Prunus mume

[junmilo]

Hi All,

I know both are for different uses..but which one would you guys use? I heard mix info.

Would you guys spray them during flowering or after flowering? For preventative measures.

Also, would you guys use systemic fungicide when the tree is still in dormancy?

Thanks,

JZ

 

[Handsome John]

Generally I use sulfur as a dormant spray (sulfur) to control insects and copper to control fungus, but I would usually use copper sprays through the season. I haven't heard of copper spraying burning the flowers but sulfur as a dormant spray will for sure burn it once it starts to open its buds. A systemic would be ideal as most Prunus species are a magnet for disease and pests but the only ones I've used are during the growing season. Also keep an eye out for peach borers as they were real bad last year!

 

[PaulH]

The label on my copper spray specifically says not to use on apricots. Since ume is an apricot I use lime sulfur.

 

[my nellie]

Like @PaulH said above, avoid use of copper on Pruni. I once used mix de Bordeaux and killed a small P. mahaleb (Saint Lucie cherry) which had just leafed out.

 

[Handsome John]

Sorry I had the wrong copper down, my mistake, the one I was thinking of was copper calcium which is used on controlling fruit diseases in prunus in orchards, But I didn't realize that apricots in general were so susceptible. Good to know for future reference since no one in my area has a lot of experience growing them.

 

[AlainK]

avoid use of copper on Pruni

This is very surprising: almost all the preventive treatments for peach-trees (leaf-curl for instance) and various Prunus are copper-based. Gardeners and horticulturists have used them for decades (actually since the end of the 19th century) to prevent fungal diseases. See : "Copper-based mixtures (such as Bordeaux mixture) and lime sulfurs are two fungicides commonly used. " (Wikipedia).

There can be problems if, and only if, the proportion of the mix is too high.

It is also reported that copper shouldn't be used for apple-trees, although I've used Bordeaux mixture for years on mine without any pb.

 

[my nellie]

Obviously the generalization ("Pruni") is misleading. My mistake...
Some useful reading damage due to copper phytotoxicity where it is clearly stated that : Copper (a general biocide) will kill fungi, bacteria, AND plant cells.
Stone fruits' leaves of the genus Prunus are more susceptible to tissue damage due to phytotoxicity than the Apple leaves (see above link)

 

[junmilo]

So would you all use sprays specifically used for rose bush? On umes? I was in Sapporo, Nagoya and Kyoto recently and was shown by local nursery owners that they use rose bush sprays for fungi prevention.