In recent days we have told you about the most common diseases that attack cherry trees during the dormant period and cause the death of plants, how to identify them and what measures to take in this regard. But in addition to this, it is important to prepare now to prevent other diseases from appearing later, causing rot in the fruit, and for that it is key to be able to help the plant throughout its development.
One of the fungi that can cause great damage is Botrytis cinerea, also known as gray mold, which causes not only rot in the orchard but can also expand in the fruit packaging boxes, causing problems not only with export, but also with the purchasing markets and of course, with the consumers.
This infection is characterized by being necrotrophic in nature, that is, it feeds on and parasitizes the host, producing toxins and components that destroy the host’s cells so that it can feed on the remains of dead cells.
Something similar occurs with Alternaria, a pathogen closely related to climate change, a fungus that appears with mycelium with a dry texture and a dark black color, resulting in dry rot in most cases, so also must be attacked in time. Although, unlike Botrytis, it does not develop in boxes and generally, it does not generate fruit-to-fruit postharvest infections.
Detection of diseases in fruit already packed
Many times we can realize that something is wrong, either by the behavior of the plant or by indicators that can be seen with the naked eye during the harvest, which allows us to discard it in time. But what happens if the cherry has already been packed? Is there anything we can do about it?
Without a doubt this is a complex issue to address since “hidden” infections or those that begin to leave signs later are difficult to treat, and it becomes very difficult to eliminate the fruit. Once this stage is completed, there are few or no measures to counteract the damage.
The key then is to pay special attention to all the cycles prior to packaging. Currently, as we have also told you, there are technologies capable of predicting, for example, the fungus Botrytis Cinerea. In addition, the application of qPCR or humid chambers can provide signals of any abnormality and possible risks to our crops.
On the other hand, it is very important to work on the sanitary aspects of the calibration and packaging process, avoiding any type of contamination. In this sense, it is key to use water that is in optimal conditions in the packaging lines, it is essential to avoid infections and this is achieved by controlling the sanitizer (concentration, pH, replacement, etc.). Furthermore, regarding biological contamination, constant plating or qPCR analysis must be performed to quantify the presence of rot-causing fungi.
Reception of the fruit at the packing station
Here is the main measurement. The moment of reception of the fruit in the packing, immediate step after harvest, can define the destiny of our work.
The people in charge of this work must be very attentive to the type of rot that exists or may exist. Even if minor signs or few signs are seen, the alert must be raised, as it is an unequivocal sign that there is a problem, and again, knowing what type of rot it is will help us in segregation.
It is important to keep in mind that each fungus has its own way of developing and attacking and, therefore, its own way of being diagnosed and attacked. This is something that will help us not only at the moment, but will also serve as a guide for the orchard in the future.
These are some of the reasons why different companies and/or producers have chosen to implement solutions that, through technology and artificial intelligence, can select the fruit in an automated way through hundreds of photographs that generate comparative schemes and that tell us which fruit should be discarded.
Once again, climate change
Finally, it may seem like a distant or not obvious topic to some, but the effects of climate change are also related to these types of diseases.
In both the northern and southern hemispheres, unstable scenarios have resulted in productions that are extremely complex to carry out and in unclear signals for the plants.
The lack of cold hours, unusual and excessive rains with drowning of plants, and heat waves, are some of the phenomena that have resulted in plants presenting accumulated stress and making them more prone to viruses and late attacks of , for example, pseudomonas, because they cannot defend themselves or their reaction is not appropriate.
From now on, regardless of the stage in which we find ourselves, it is essential not to leave our crops alone and take into account the irrigation conditions, the application of biostimulants and biocontrollers, among other techniques that it will not hurt to consider, since it is a fact that our cherry trees today are much more exposed than before.
Check out the full interview with Héctor García, General Manager and Co-founder of Diagnofruit, who referred to health in orchards, the main rots and provided recommendations for the coming months.