A warm, rainy spring can put a strain on cherry orchards: advice from an expert

A fruit production specialist at INIA Quilamapu has warned that excess water during winter and early spring can cause complex problems in tree roots and negatively affect bud break and flowering. Rainfall close to harvest could increase the risk of fruit cracking and rot.

The weather conditions forecast for spring, which due to the El Niño phenomenon is expected to bring periods of rainfall and above-average temperatures, pose major challenges for the national cherry industry.

According to Cristian Balbontín, a fruit production specialist at INIA Quilamapu, one of the main risks is associated with waterlogging in cherry orchards during winter and early spring. This condition can cause root asphyxia and affect the subsequent stages of tree development.

Roots and flowering

The researcher explained that the release of cherry trees from dormancy mainly depends on the signal generated by the chill accumulated in the buds, which is why the condition of the roots does not directly alter this process. However, he pointed out that bud break and flowering require the metabolic and hormonal support provided by the root system, and it is precisely at this stage that excess water can have a significant impact.

“In saturated soil, oxygen is depleted within a few hours,” Balbontín said. Under these conditions, the roots shift to fermentative metabolism, which acidifies the tissues and causes them to die, reducing the tree’s ability to absorb water and nutrients.

At the same time, carbohydrate reserves are depleted and the synthesis of cytokinins, hormones that are essential for flowering and the initial growth of the fruit, decreases.

The importance of drainage and nutrition

The INIA Quilamapu researcher explained that the effects of waterlogging in cherry orchards become apparent through uneven bud break, which compromises the synchronisation of flowering and, consequently, pollination.

This is compounded by the reduced availability of micronutrients such as boron and zinc, whose uptake is particularly impaired when soil oxygenation is insufficient. Excess water can also accelerate the loss of available nitrogen, directly affecting subsequent fruit growth.

In light of this situation, Balbontín recommended identifying in advance the areas of the cherry orchard most exposed to the risk of waterlogging, particularly the lowest sections of the plots, and ensuring the rapid drainage of water.

To achieve this, he suggested installing or improving surface drainage systems in the lowest areas and at the ends of the plots, as well as carrying out preventive cleaning of channels, ditches and pipes before the rains arrive.

Preventive management

He also recommended carrying out subsoiling in areas characterised by compacted soils or the presence of clay layers, provided that the soil is dry. Regarding tree nutrition, he indicated that foliar applications of boron and zinc before the pre-flowering stage could be used as a preventive measure to compensate for reduced root uptake.

A further cause for concern is the disease caused by Phytophthora spp., an organism belonging to the oomycete group that is very common in soils and responsible for severe damage to roots.

According to the researcher, the risk increases when saturated soils and above-average temperatures occur simultaneously, as these conditions favour its development and make preventive management particularly important.

Preharvest rainfall and fruit quality

Rainfall close to the harvest period, which runs from October to January depending on the area of the country, represents another challenge for cherry growers due to its relationship with the occurrence of splitting, or cracking, and associated rots.

Cristian Balbontín explained that the fruit’s susceptibility to cracking is not determined exclusively during the preharvest stage, but begins to develop at an early stage, during the cell division that occurs in the weeks following fruit set.

“During this period, a significant part of the thickness and quality of the cuticle is established, which will determine the fruit’s resistance to water penetration.”

Fruit quality

The researcher emphasised that “INIA has long pursued a line of research into the factors that help preserve and improve fruit quality under conditions of climatic stress, such as those forecast for this season.”

In this context, he stated that the application of hormonal elicitors, particularly jasmonates, has shown favourable results in improving the water resistance of fruit.

He added that the Fruit Quality Laboratory at INIA Quilamapu is evaluating various technological solutions, including plant growth regulators, biostimulants and storage systems, aimed at reducing the impact of adverse weather conditions on cherry quality and postharvest life.

Source: www.portalagrochile.cl

Image source: PORTAL AGROCHILE - INIA

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