We spoke with Carlos Tapia, Cherry Production Specialist, Founder and Technical Director of Avium, and Héctor García, Co-founder and General Manager of Diagnofruit Laboratories, who provided their recommendations.
Undoubtedly, the recent rainfall and subsequent floods that affected the central zone of Chile have revealed how susceptible certain areas can be to the forces of nature. Entire cities were submerged, and numerous orchards of different species turned into veritable rivers.
The water, which has been scarce in the central zone for over a decade, became the protagonist of a complex situation: cherry orchards flooded, and a series of questions arose as the water advanced.
What should be done after the flood? Is it possible to save a cherry orchard that was submerged under 1.5 meters of water in some areas or had its roots exposed?
Cleaning up the orchard
“First of all, we need to support the producers who are facing this extremely difficult situation. The scenes we have witnessed in some cases are quite devastating and unfortunate. As a team, we have prepared a very simple document with 5-6 points that form the basis for dealing with this situation. The first point is to clean up the orchard. There is garbage, plant residues, and debris carried by the rivers. There are irrigation lines that will probably need maintenance or significant repairs. That’s the first step,” said Carlos Tapia.
The floods created two scenarios in the orchards. The first scenario is plants with exposed roots due to water erosion, and the second is orchards with raised soil levels several centimetres higher than before the weather event.
“In the first case, the roots need to be covered again. We need to mound soil around the roots to prevent dehydration and exposure, ensuring the plant remains alive. In the other situation, where a new layer of soil has been deposited over the original soil, probably much higher than the original level, my recommendation is to aerate the tree collars, create ornamental basins. However, removing all the soil that was washed there is practically impossible,” added Tapia.
One of the major concerns during this time of the year is phytosanitary issues in orchards, which became even more relevant after the floods. Héctor García, Co-founder and General Manager of Diagnofruit Laboratories, agrees with Tapia on the need to clean the orchard as one of the first tasks after the weather event.
“We have been assessing the situation, and today we need to try to clean the orchards. It is not an easy task and can be quite expensive because some orchards are filled with debris, which prevents any application from reaching the wounds. Currently, the riskiest aspect is that the debris carried by the water may have caused injuries to the wood. We have even seen buds being washed away by the water, so there are numerous wounds. This can lead to the entry of wood fungi, and if there is a temperature peak, bacteria can thrive. However, applying treatments at this stage might not be very effective, so the first step is to evaluate and clean,” explained García.
Should the phytosanitary program be modified due to the floods? Carlos Tapia, answers this question: “Regarding the phytosanitary program, in special and complex situations, we should consider incorporating some biological fungicides in addition to the copper applications typically done during winter. Lastly, we need to conduct new soil analyses for these types of orchards. The soil has changed completely, so we need to assess our soil and how we will redefine the pre-established soil programs.”
New soil analysis
These analyses should be carried out by August to reformulate, if necessary, the soil programs that should start in the first weeks of October.
Regarding the necessary applications for post-flood cherry orchards, Héctor García also provided recommendations: “Currently, we recommend starting with copper applications and using broad-spectrum fungicides to reduce the overall inoculum load. We need to continue monitoring the orchards as cytospora may appear in some cases. These fungi are soil-borne, and if there is excessive water around, they find their opportunity. Although they are not winter fungi, we cannot predict the weather, as some days are quite mild. We need to stay vigilant, monitor the tree collars. If tractors cannot access the orchards, we need to apply sprays using backpack sprayers. Dealing with cytospora is a bit more complex, so we will continue to monitor it because controlling it requires additional measures. For now, the most urgent action is to cover wounds and assess if the plants have bent. We need to observe and make direct applications if necessary, such as using paint to aid in healing and prevent the entry of fungi and bacteria,” concluded Héctor García.
Both specialists recommend conducting a comprehensive assessment of each orchard, considering that each case is different. They suggest creating a priority list and addressing each item based on its level of urgency, in preparation for the upcoming cherry season.