This study, which complements pioneering research from the 1990s, explains the mechanism of action and the precise timing for treatment. Cracking occurs when the fruit's pulp grows faster than its skin, typically after the first autumn rains. If the peel does not expand at the same rate, it breaks, leading to losses that can reach 40 percent of the harvest in mandarins like the Nova variety and some orange types such as Navel.
“"Oranges and mandarins may seem resistant fruits, but those with very thin skin tightly attached to the pulp are very vulnerable to a problem that greatly concerns farmers, which is cracking."
The research, conducted in commercial Nova mandarin plantations in the Valencian Community, reveals that the application of 2,4-dichlorophenoxyacetic acid (2,4-D), in its new dimethylamine salt formulation, during a very specific phase of fruit development (when the cell expansion stage begins), can reduce cracking by up to 70%. This is achieved without affecting fruit size or quality, and the decrease in damaged fruits translates into a significant increase in final harvest yield.
“"The secret lies in strengthening the fruit's skin from within. Thanks to the treatment, the peel cells become larger, more flexible, and have thicker walls. This gives the skin a greater capacity to stretch as the fruit grows, without breaking."
Among the advantages of this new 2,4-D formulation, it stands out that large quantities are not necessary; rather, it's about applying it at the right moment. A single application during the early growth phase of the fruit has already shown great results. It is crucial to wet most of the fruits on the tree, as the effect is direct on the outer part of the peel. In some cases, the reduction of damaged fruits was almost by half with a single targeted treatment. The study has been published in the Journal of Agriculture and Food Research.
