The application of copper can be essential in cherry orchards in formation and production if you want to prevent certain diseases, one of the main ones being bacterial cancer, but when to apply coppers in cherry orchards?

Initially we could talk about three periods: winter, autumn (leaf fall) and early spring, this is because the main objective is to maintain low populations of Pseudomonas, especially at critical moments of infection, that occur due to the phenology of the plant and its close relationship with the climate.

In simple words, during dry and hot seasons, or on the contrary, very cold ones, populations remain at very low levels. On the contrary, in spring, where there are sessile tissues such as flowers and temperatures are mild with the possibility of frost -but then conditions recover-, it is the time of greatest risk due to significant population increases that could end up triggering an infective process. In autumn, humidity increases with mild temperatures and there is the presence of wounds due to falling leaves, making it another critical time to take care of.

Relevance of copper in phytosanitary programs

In recent years, technologies that consider copper nanoparticles as a powerful source of pathogen control have been generated. In this way, it is a fundamental tool to maintain the phytosanitary status of crops such as stone fruit and walnut trees, although it must be used with proper measure.

Should copper be applied regardless of the geographical area where the orchard is located?

We cannot ignore climate change in any area and new varieties sometimes imply new risks and doubts, so we must leave the least amount of uncertainties associated with the protection of the crop, also considering that this type of product acts as preventively, there is not much room for speculation. Depending on the area, we could shorten application windows or add other strategies.

Recommendations when applying copper

The ideal is to always apply copper only in the pond, because what is sought is a release of Cu+2, without interference. Some penta-hydrated copper sulfates require the use of pH correctors to increase the release of ionic copper, so when using this type of product you should always read the recommendations for use.

What to do in the case of floods?

In damaged orchards the number of applications can be increased circumstantially. If we manage to enter the garden to apply, and we have cleaned the plants, an application of copper sulfate could deal a blow to the existing populations of Pseudomonas and some fungi, in some way the idea is to reduce the risk of infection in wounds produced by the material carried over from overflowing rivers and canals.

After that, the usual winter coppers plan could be made. Now, according to the status of the orchard, synthetic fungicides and/or biological control can be added, if there is a threat of wood fungi or the appearance of Phytophthora derived from heavy flooded soils, but this analysis must be carried out case by case, so we must review plants, record wound behavior, make a diagnosis and conclude appropriate management.

Originally posted on Smartcherry.cl

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