Santiago, May 2020.- Undoubtedly, a correct application of copper is the fundamental tool to keep under control the diseases that affect crops during autumn and winter, for example, bacteria Pseudomonas syringae with its pathological variants (Psa and Pss; pv. actinidiae and syringae, respectively), wood fungi, among others.

"One of the central points for a correct management of deciduous fruit trees is an adequate application program for cupric products that will help to keep these diseases under control", indicated the phytopathology specialist at INIA La Platina, Sylvana Soto.

It is important to bear in mind that this phytosanitary measure, for the containment of diseases, must be implemented in orchards and nurseries within an integrated management plan throughout the year. "Although this is known to producers, there are concepts about the use of agricultural copper that it is important to clarify in order to use it rationally, optimize its use and achieve better results", emphasized INIA researcher La Platina.

Similarly, the expert added, "the correct control of diseases should place emphasis on other aspects that condition the success of phytosanitary programs based on the use of copper, such as: the timing and quality of the applications, within the legal framework established by the Agricultural and Livestock Service (SAG) ”.

Next, Sylvana Soto gave the keys for a correct management of copper applications that help control diseases that affect deciduous fruit trees, during autumn and winter:

  1. Most of the copper-based products used in agriculture are insoluble salts. For this reason, when they are used on fruit trees, in recess or with green tissue, or on any other crop, solid copper particles remain which, once the application has dried, have no greater bactericidal action. However, when free water is present, these particles will be able to release small amounts of metallic copper that will be able to poison microorganisms.
  1. When there is free metallic copper in the medium, fungi and bacteria absorb these ions which, once inside the cells, may bind different molecules, altering their functionality and generating various cell damage, including the alteration in the functionality of cell membranes.
  1. Whenever copper is used to control disease, regardless of its formulation, bacteria will be poisoned by free copper ions. In practice this implies that it is not possible to consider the alternation of copper assets as an anti-resistance management.
  1. As the action of copper occurs outside the plant and in a preventive way, the copper must be applied before the environmental conditions exist for the infection to occur.
  1. Prevention should occur at key moments such as leaf fall, frost, injuries caused by pruning and other winter work, etc.
  1. The application must achieve the best possible coverage, since the pathogen will be able to enter without problems through the unprotected sectors, due to a bad coverage of the product.
  1. According to the results of tests carried out by the INIA La Platina Phytopathology team, copper sources control the disease caused by Psa in kiwis and there is no difference between them. Likewise, the doses of copper used in the country, at the recommended intervals, are not limiting for the control of Psa, since there were no statistical differences in effectiveness if the minimum or maximum dose recommended on the labels for this disease is used. , considering one-month intervals during the break.

About INIA

The Instituto de Investigaciones Agropecuarias (INIA) is the main institution for agri-food research, development and innovation in Chile. Linked to the Ministry of Agriculture, it has a national presence and a work team of more than 1,000 highly qualified people. It executes an average of 400 projects per year around 5 strategic areas: Climate Change, Sustainability, Food of the Future, Emerging Technologies, and Extension and Training of Capacities. These initiatives contribute to the sustainable agri-food development of the country, creating value and proposing innovative solutions to farmers, strategic partners and the population, generating a social profitability that varies between 15% and 25%, for each peso invested in each of their projects.

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Press contact: María Jesús Espinoza, INIA La Platina communications manager