According to official data from the Office of Agrarian Studies and Policies, ODEPA, the area of cherry trees in Chile currently reaches 39,645 hectares, however, for many people linked to the field, the figure would actually be close to 50,000.
The expansion of the cultivation of this fruit species has been such that today it is present from Ovalle in the north to Chile Chico in the south of our country. Fields that used to be table grapes, vineyards, apple trees, among others, have been replaced; This situation has caused cherry orchards to be affected by pests that were common to other crops or fruit trees.
The Agronomist Engineer and Director of Syngenta’s MIPNET Monitoring Network, Cristian Arancibia, highlighted the importance of correct pest management, considering that this is essential, especially for export fruit: “There was always the stigma that cherry trees It had no pests, and in general and historically, producers did little phytosanitary work, but as the area planted increases due to the opening of markets, pests and restrictions appear that make it necessary to implement control programs. When a market opens, a protocol is established with that country of destination. This agreement certifies the health of what is exported; It is not to arrive and sell. For example, China, there is a protocol behind it, a job that must be carried out to be able to reach that market with fruit without pests that are present in Chile, but are not present in China,” explained Cristian Arancibia.
But what are the main pests that affect cherry trees and how to manage them post-harvest? “scales, Phytophagous Mites, there are several species that we must control to prevent leaf deterioration, etc., and even Drosophila suzukii”, explained Arancibia.
In the case of scales, the professional referred to two species that could affect a cherry tree; the classic Saint Joseph Scale(Pernicious Diaspidiotus) and the Coma Scale (Lepidosaphes elm), which is much more secondary in most deciduous fruit trees, but in the case of the cherry tree it is a quarantine species for China and the main cause of rejection of export cherries for that country.
When can they be controlled?
There are three control periods depending on the species. «The control of scales in spring is complicated because we have little time and we must comply with the lack of phytosanitary products and try to achieve the greatest effectiveness; We can control the Coma Scale during the first half of October. However, the early harvest of cherry trees, from the end of October onwards, largely coincides with one of the migration cycles of Escama de San José, so we miss out on one of the best control opportunities. Therefore, we must implement management programs at winter exits, that is, before sprouting, where we must differentiate these species, since it is very effective for Escama de San José, but not very effective for Escama Coma, because their cycles do not coincide. . Post-harvest is different, since we have a lot of time to carry out efficient management, but it depends on the biological cycle of each species, because it must be applied when the pest is most susceptible to control; For example, if we are harvesting an orchard in November where we find scale, either by prospecting in the field or by detecting it in the packing plant, a control should be done coinciding with the post-harvest summer migration, only in January or February. depending on whether it is Coma Scale or San José Scale, respectively; Inclusively, Escama de San José can be controlled in a third biological cycle during April depending on weather conditions. Also, it is very common to detect Phytophagous Mites or even mealybugs, in which cases the management of phytosanitary products will depend on the biological cycle of each pest species and its control thresholds”, explained the Director of the Syngenta Monitoring Network, Cristian Arancibia.
The well-known spider mites or Phytophagous Mites is another group of pests that affects cherry trees and can seriously damage the leaves of the trees, essential for different processes in the orchard, such as accumulation of reserves, among others.
“There are different species, European Red Spider (Panonychus ulmi), Bimaculate Spider (Tetranychus urticae) and the little spider of the pastures or pasted (T. deserts); these species do direct damage to the leaves and, therefore, can also affect the accumulation of dart reserves for the next season, so if there is a problem of “summer scratches”, with a very high population of Phytophagous Mites, independent of the species, you are going to have reserve problems and next season we may have poorer flowering, weaker flowers or smaller fruit size. It can affect the productive potential of an orchard, because if you don’t manage it you can have defoliation in the middle of January”, Arancibia specified.
But without a doubt one of the most complex plagues in recent years isDrosophila suzukii; It not only affects cherry trees, but also other fruit trees, and even wild species, which makes its control even more complex.
“When one speaks of a species that is as prolific and polyphagous asDrosophila suzukii, that attacks a large group of fruit trees, which is developing in wild species, in blackberries, which you have in the field and which can have up to 15 generations per year, there is an urgent need to establish a preventive pre-harvest management program with agrochemicals highly effective, since there is not just any mode of action that works satisfactorily; even the type of formulation of the product, adding to cultural management and strict monitoring, is essential, since the possibility of having failures and generating economic losses are very high, more than with other pests, which we are used to managing. . It is not a quarantine pest, in 2008 it was detected in Europe for the first time Drosophila suzukii and in four years it covered the entire continent. In North America, it was also detected in California in 2008 and in a short period of time it spread from Mexico to Canada and between the west and east coasts. In Chile it was detected for the first time in 2017 and already this last season it was declared a pest present from the O’higgins region to the south. When the orchard is harvested, fruit remains on the trees and fruit also falls to the ground. This fruit can be a source of propagation ofDrosophila suzukii in the field and must be monitored, since within the cultural measures for the management of this pest species, the fruit that remains on the trees or that falls to the ground is essential that it be removed or at least treated with agrochemicals in post harvest.” Cristian warned Arancibia.
For the Agronomist Engineer and Director of the Syngenta MIPNET Monitoring Network, it is very important to have adequate equipment and in good condition to carry out good control and effective management of pests; This would be one of the bases for the success of product applications: “Within our area of service management, such as the Monitoring Network, is the calibration of equipment. In more than 12 years, in general, when an equipment diagnosis is made, close to 90 percent have some failure and a little more than half have problems with the nozzles, not to mention other things such as speeds and volumes applied. per hectare as examples. Much remains to be developed to achieve a good application, going through good diagnoses and therefore good equipment calibrations, with which you make sure you can reach the objective, because the application itself is to place where you want the product with which you are going to control the pest or disease; The objective of the application is to get where you want to place the agrochemical that you are applying, so if you have poorly calibrated equipment you will not get there and you will have problems”.Finally, the specialist warned that pest management should not only focus on the fruit trees inside the orchard, but also on the perimeter of the field, the live fences, what surrounds the orchard, for example, bushes, native forest, in the neighboring crop, as they can be sources of increased population of pests that could finally affect a cherry orchard, such as the most recent,Drosophila suzukii or spotted wing fly.