After the detection of the Fusarium oxysporum (FOC) strain 4 tropical (R4T) fungus in Venezuela, specifically in the states of Aragua, Carabobo and Cojedes, the National Institute of Integral Agricultural Health (INSAI) issued a statement to declare a state of phytosanitary emergency in the entire national territory.
By La Patilla
Feb 19, 2023
Although this pathogen does not represent any risk to humans, the Fusarium R4T is responsible for causing wilting in banana, plantain and mole plantations, generating great losses in the production of these crops.
Currently, Venezuela is the third country in Latin América to detect the presence of the fungus, Colombia being the first Latin American country to confirm its presence in 2019 and later Peru in 2021.
To learn more about this pathogen that keeps Venezuelans on alert, lapatilla.com spoke with Rafael Mejías, an agronomist, Phytopathology researcher and head of the Plant Clinic of the Faculty of Agronomy of the Central University of Venezuela (Fagro-UCV).
– How was the presence of the fusarium fungus detected in the country?
In view of the concern about the affectation of musaceae plantations, mainly in Aragua State, the Faculty of Agronomy, specifically the Laboratory of Phyto-pathogenic Bacteria and the Clinic of Plant Diseases, together with the Laboratory of Biotechnology and Plant Virology of the Venezuelan Institute for Scientific Research (IVIC), submitted a research project to the Inter-American Institute for Cooperation on Agriculture (IICA).
We as a university went to the Insai and carried out the sampling in the states of Aragua, Carabobo and some samples that came to us from Cojedes collected by the Insai. Subsequently, between the Phytopathogenic Bacteria laboratory and the Plant Diseases Clinic, the isolation of plant tissue began and mainly fungi and bacteria began to emerge.
From there the DNA was extracted, the molecular tests were carried out at the IVIC, it was sent for sequencing at the Macrogen company and once the results with scientific evidence were obtained, the information was supplied to the Insai and from there all this phytosanitary alarm state has been declared because it is a fairly aggressive pathogen.
– Although the consumption of bananas or plantains from plantations infected with fusarium does not represent any risk to humans, how does the fungus affect it?
It is very important to clarify that the fruit does not host the pathogen. In other words, commercial traffic and consumption will not generate any epidemiological state that could cause us new outbreaks, nor will it obviously affect the human body, since there is no scientific evidence to support it. It must be clarified that this pathogen currently arrived in Venezuela, but it has been present in other countries for many years.
– If Colombia detected the presence of ROC R4T first, why was the entry of bananas from Venezuela prohibited?
Although the fungus was detected a few years ago first in Colombia and then in Peru, that does not mean that it comes from these countries. It is only a measure that we are also taking by not accepting plant material from countries affected by this fungus, since it could generate new outbreaks. It is a matter of epidemiological protection.
– Is there a record of affected production units?
In the first phase of the investigation –which is the one we have just finished- we dedicate ourselves to black and white. We only sampled plants that showed suspicious symptoms from specific production units, all of which tested positive.
Soon we are going to start a second phase of epidemiology in which we will find out the number of hectares affected, which production units and how many are being affected by this pathogen or any other pathogen.
– It is said that smuggling could be related to the presence of the fungus in Venezuela, what is true of this hypothesis?
I don’t think it’s such a well-founded hypothesis. When plant material is going to be moved, every certain “alcabala” (checkpoint) you have to stop and sign a mobilization guide issued by the Insai.
There are many hypotheses but none with scientific foundation. For this reason, we are very concerned because there are many people who have no knowledge of the research that was led by Dr. Yonis Hernández and myself on behalf of Fagro-UCV, and Dr. Edgloris Marys on behalf of IVIC, and these provide information about it.
– What is being done to contain the spread of the fungus?
The Insai issued a series of phytosanitary measures with the intention of containing (its spread). These include the making of “rodaluvios” (wheel baths), the placement of foot baths and the disinfection of work tools with fifth generation or higher quaternary ammonia, because it has already been proven that they are totally effective in disinfecting and attacking the fungus.
As a preventive measure, there is also the use of biological products such as trichoderma or bacillus subtilis applied to the soil to increase the beneficial microbiota.
Another recommendation to contain the fungus is to control the weevil, an insect that affects bananas and opens wounds in the corm, making it easier for the pathogen to enter. Furthermore, when the weevil feeds on a fusarium infected plant, the weevil becomes a transmitting agent.
– Now, what should growers who suspect the presence of the fungus do?
The first thing they must do is immediately call an Insai official, they will evaluate the symptoms and take samples, then the results are returned and measures can begin to be taken.
Now, in the case of not wanting the production unit to be contaminated with the pathogen: The visit of people that do not belong to the production unit should be avoided as much as possible; Also, avoid the displacement of vehicles within the production units, have “wheel baths” and “foot baths”; Do not plant plant material whose origin is not known, because the plant may be apparently healthy but contain the pathogen; and finally, apply biological products to the soil so that there is a bank of beneficial microorganisms in the soil.
– How long would it take to eradicate the fungus in the Musaceae?
This is very complex. We are going to live with this pathogen, we are not going to eradicate it 100%. Plant material that is tolerant and resistant to this pathogen already exists. What we have is to resort to that plant material and have it planted.
Completely eradicating the pathogen in the medium term is almost impossible, since this pathogen can last up to 30 years in the soil even if all these measures are applied. The important thing is that there is an integrated management and that we can live with the pathogen.
– Could the current plantain, banana and topocho plantations become extinct?
Currently there is no plant material planted in Venezuela that is resistant to fusarium. Therefore, if the pathogen reaches a production unit and the corresponding phytosanitary measures are not taken for the control and containment of the pathogen, it can generate a great affectation in the production of these items. However, it is not a dead end tunnel.
– How does the presence of Foc R4T economically affect producers and the community in general?
It can affect the economy of the producers because the affectation of this pathogen causes a decrease in production and this implies that the producer will have less income. Logically this implies that economic dynamics are affected because there may be direct or indirect unemployment, there will also be less commercialization of bananas. But what we want to avoid is getting to that point.
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