Parka, Cherry Split Protective Emulsion and Other Benefits
Studies from the University of Concepción led by Richard Bastías indicate that the use of Parka reduces damage from moderate rains before harvest in cherry and blueberries. For her part, Karen Sagredo, academic and researcher at the University of Chile, has discovered other interesting benefits in cherry, such as mutual enhancement with the use of gibberellic acid, less postharvest dehydration as well as less browning of the pedicel; and in apple it protects against severe sunburn.
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In a recent article by Richard Bastías and Karen Sagredo et al., It is indicated that there is a majority consensus that splitting constitutes the greatest current threat at the level of cherry orchards. During stage III of fruit development, growth accelerates as a result of the elongation of the mesocarp cells. This expansion is contrasted with the decrease in the deposition of structural components of the cuticle, which makes it less elastic.
As a consequence, a series of microscopically observable cuticular microfractures, known as “microcracking”, develops. Under an event of rain, these microscopic imperfections increase in size and affect the development of the crop to harvest. There is widespread agreement that splitting damage is caused primarily by water ingress through the cuticle. However, an additional component of this damage comes from the entry of water via the vascular route and through the roots. Depending on their cause, the cracks are located differently. In general, those located in the pedicellar and distal area are associated with the displacement of water on the surface of the fruits after a rain. The cracks on the sides, the cracking of which seriously compromises the mesocarp,
A PHYSICAL BARRIER AGAINST THE ENTRY OF WATER INSIDE THE FRUIT
Bastías, Sagredo et al . point out that the use of lipid protectants of natural origin, such as carnauba wax and vegetable oils, have been used in Chile and the world with different degrees of effectiveness to control cracks in cherries. Due to their lipid nature, these protectors help in some way to waterproof the cuticle, acting as a physical barrier to the transport of water from the surface of the fruit to its interior. The most recent formulations act as true cuticle supplements (SC), thus allowing, in addition, to improve the stability of this membrane.
Recent trials in our country on varieties such as Lapins and Sweetheart show that the application of SC type protectors are effective in controlling splitting. Efficacy improves when used in combination with mineral salts such as calcium chloride, and an early application is made (freshly set fruits) followed by a complementary application in the state of straw-yellow fruit.
Also in Chile a study determined that the cuticle protector must have in its formulation the adequate amount of adhering agent to ensure a better distribution of the drops. This avoids the loss of product due to excessive runoff and favors a uniform protection from the area of the pedicel cavity to the distal area of the fruit.
U. DE CONCEPCIÓN TRIALS: THE PRODUCT EFFECTIVELY HELPS PREVENT DAMAGE
Dr. Richard Bastías, from the University of Concepción, specifies that through an agreement with the company Cultiva, he studied the use of the parka product emulsion as a method to control splitting:
–We did several tests, we studied various aspects, from field application, through evaluations of how the emulsion would look on the fruit, to microscopy to see the fractures of the fruit. The results are positive. We conclude that the solution works under rainy conditions that are not so extreme. We calculate that over 20 mm of rain, effectiveness is lost a little, but for rainy conditions close to harvest and even a little earlier, which are common and generally generate cracks, the product effectively helps prevent damage. The classes of splitting that decreased the most were those of the calicinal and pedicellar type.
–With a roof, is its use not required?
–With a roof, it will contribute to making the cuticle of the fruit more resistant, because under cover there is also some damage due to splitting.
– Are there differences in its effect between varieties?
–In general, in blueberry and cherry, what we saw is that in the early varieties, more exposed to the risk of precipitation, there was a better response to Parka.
–The line of work in this type of products is interesting –states Richard Bastías–, because they simulate in some way the cuticle that the plant has as a physical barrier to protect itself from the attack of insects, adverse weather conditions, radiation, different agents biotic and abiotic. This is a product that aims as a cuticle supplement. Basically, as it matures, the deposition of the cherry cuticle diminishes and there is a loss of elasticity. It is like a balloon that inflates to which at some point you add additional air pressure and it bursts, because the elasticity of the cuticle is no longer capable of supporting the cellular expansion of the cherry. This emulsion supplements the cuticle and allows it to have a little more elasticity. It works by waterproofing, preventing some of the ingress of water through the cuticle, and also reducing splitting by direct ingress of water through the fractures. I understand that the University of Oregon in the USA, where this technology was developed and later put into practice for cherry split control, is currently studying it in other applications.
MUTUAL ENHANCEMENT WITH GIBERELIC ACID AND LOWER DEHYDRATION IN POST-HARVEST
For her part, Dr. Karen Sagredo, from the University of Chile, indicates that she initially evaluated the use of Parka for two purposes: in cherry, thinking about splitting, and in apple tree for sunburn.
In cherry, he found that split control results could differ depending on many factors, such as variety, firmness, concentration of soluble solids, calcium nutrition, etc. What most attracted his attention from the studies was another effect of the emulsion:
–The most promising characteristic corresponds to the application associated with gibberellic acid, because both products are enhanced. Parka favors the penetration or the soaking time so that the gibberellic penetrates well, reducing the susceptibility to splitting and increasing the firmness of the fruit. We have been working with Gibberish for 5 years and it has been spectacular. It effectively lowers the susceptibility to splitting, the fruit is firmer and, apparently, Parka helps to reduce microcracks, but mainly it also favors the wetting action time so that the gibberellic can penetrate well, and increases the effect. . But that we have to validate now with specific tests. In postharvest, additionally, Parka generated less dehydration and less deterioration of the pedicel.
-As it is a phospholipid, it may reduce the respiratory rate, we must investigate. Imagine, arriving with a cherry with less dehydration, less water loss and the greenest pedicel, I think it is a tremendous plus from the price point of view at the time of sale in the destination market. These are interesting news, because you start to rehearse one thing and end up discovering others.
Message from Samuel Rodríguez
DEAR FRIENDS AND PRODUCERS:
In the 113th edition of Redagrícola, the article “Advances in the physiology and management of cherry splitting” was published, by the authors Richard Bastías, Karen Sagredo et al ., Within the framework of the technological program “Center for research and innovation in fruit growing for the southern zone ”(16PTECFS-66647) and its project“ Technological package for the sustainable production of cherries for export in the south central zone ”. On that occasion, the authors thanked the financing provided by the company Cultiva (USA) to be able to carry out the cuticle supplement studies.
We are very pleased and stimulating to receive the thanks from Richard Bastías and Karen Sagredo, together with their teams of researchers from the University of Concepción and the University of Chile, respectively.
Since Cultiva acquired SureSeal ™ technology, developed by Oregon State University; In Chile, Spain, the USA, Italy and Turkey as well as in other countries, we have validated the effectiveness of the Parka® product (based on SureSeal) with the main universities, research centers, consultants and researchers in those nations. At the same time, as detailed in that article, we have supported research into the causes and factors that affect cuticle damage in fruits, as well as other tools and solutions to the problem.
Thanks to these studies, Parka is currently the only cuticular coating that has been shown to reduce micro-cracks in cherries, table grapes and blueberries.
Regional Manager Europe and LATAM Cultiva
VALUABLE EFFECTS ON APPLES
In her evaluation of apple trees, Karen Sagredo determined important benefits of Parka as a kind of sunscreen:
–Applying it early reduces the cracks that occur in the calicinal area in Fuji. When we use it, we never have severe sunburn. It attenuates or delays the accelerated yellowing that occurs in that variety when it is left to take color. And it does not cause the problem of kaolinite, which, although it really lowers the temperature, can generate a kind of staining or uneven coloration. If we compare it with a kaolinite or with wetting, it is definitely best to wet, but not when you have water problems and it also involves an entire infrastructure. As for kaolinite, I like it a lot, however due to the issue of staining I hardly recommend it anymore.
-So Parka would be a good option?
I think it is a good option, yes.