The content of this article 'Managing cherry orchards after rain, snow or hail' was prepared by Gamalier Lemus, Juan Hirzel, Andrés France and Rodrigo Bravo from INIA, and has been revised and republished by FreshFruitPortal.com.

Cherry orchards are adapted to cold temperate climates, however, they must be fitted with shelter against adverse weather conditions, such as frosts, high winds, rain, hail or snow.

This article will provide suggestions to mitigate the damage caused by situations that caused destruction and damage to orchards due to sudden and unexpected snowfall.

There are times when conditions create adverse events in some areas; which can cause damage, especially in fruit orchards. In these areas, infrastructure should be built to protect fruit trees, resistant to events of this type; despite upfront costs, as mitigating damage results in significantly higher cost.

Damage to cherry orchards

Snow damages wood and other plant tissues; which begin to behave like senescent tissues, generating hormones such as Ethylene and Abscisic Acid that limit vegetative development and alter flowering and fruit development.

Therefore, damaged wood must be removed by pruning. This removal of damaged tissues allows greater vegetative growth in this same season, better production of new wood and accumulation of reserves for the following season.

As agronomic management practices for orchards in development and production; and in which wood was damaged, sanitary pruning should be considered, in order to eliminate the damaged tissues.

Depending on the degree of damage in cherry orchards, the following practices should occur:

Orchards with a lot of wood loss

Remove damaged wood with pruning and disinfect the cuts with pruning paste or spraying products.

When using the pastes, the most important thing is covering the cuts, so there are no unpainted areas.

If the plant is already budding the paintings will be removed by the sap, so it is better to use microorganism paints so that they can use this sap to grow and thus protect themselves.

Orchards with little wood loss

Eliminate damaged wood with pruning and protect these cuts with pruning paste. As in these cases, the cuts are smaller and heal faster, the paints can be replaced by spraying products.

To protect against Pseudomonas, antibiotics or Bacillus subtilis can be used, while to protect against fungi, use fungicides such as boscalid or fenbuconazole.

Later, carry out applications that the orchard has already calls for to ensure normal operations.

Subsequently, continue with the applications of the disease management program that have the orchard has planned.

Suspend Nitrogen applications until December or January to avoid tissue poisoning (the trees have enough nitrogen reserves for their first two to three months of growth).

Adjust the spring fertilization according to the load for Phosphorus, Potassium, Magnesium and Calcium. Then, from December or January continue with normal fertilization.

Maintain the normal fertilization program of the orchard, but reduce the dosage of spring nitrogen by 50%, to avoid intoxication of plants by this nutrient, since the trees will present a lower need for nitrogen in spring (vegetative growth based on reserves of nitrogen).

From sprouting onwards, apply algae-based biostimulants and/or amino acids whenever possible every 7 days, to stimulate the endogenous synthesis of vegetative growth hormones.

Bacterial cancer in cherry orchards

Since the orchard is weakened due to the damage caused by the cold, it may be necessary to carry out a greater number of applications against bacterial cancer; because this disease is does well when trees are under stress.

In such cases, the antibiotic applications, rotating between the products that exist in the market (streptomycin, gentamicin and kasugamycin) during bud break and in particular after events such as rain and frost, will help to reduce this disease.

Wood fungi, which are becoming more and more common in the southern zone, must be controlled with fungicides at sprouting and in case of damage to the wood.

Source: www.inia.cl