Two more difficult nights and mornings of agricultural frost. This is the observation made by agroclimatologist Serge Zaka who, on cartography regions most impacted by the risk of loss. The frost in question is called “radiative”, that is to say it comes from the accumulation of cold air on the ground after sunset.
“The temperature goes negative more towards the middle of the night, and until 7 a.m.,” he explains. Damage to crops depends on this temperature but also on the duration of exposure to frost and on the plant, whose cold resistance indices vary from one species to another. And the apple, in this spectrum, has serious advantages, especially if we compare it to vines or apricots.
Concern in Limousin
“The apple is rather well off, it is one of the species in France which historically opens its buds the latest,” notes Serge Zaka. It is at a slightly less developed flowering stage, so it is less sensitive than other crops to cold. » Present in many territories, apple trees are however not in the same boat. “The south-east is lucky, there is currently the mistral which prevents the film of cold from settling on the ground,” he analyzes.
Maine-et-Loire and the South-West should also be spared. Serge Zaka, on the other hand, says he is more “worried” about Limousin, which has the only AOC Apple. “Not all plots will reach the damage threshold, but this is the region where the apple is likely to have the most loss of yield. » But here again, this should be case by case, depending on the microclimates, with plots at the bottom of the valley where the cold accumulates more, and others “which will survive, protected by the wind or the covers cloudy”.
These freezing nights are not exceptional
Therefore, it is difficult at the moment to assess the consequences of this wave of frost on the apple harvest, all varieties of which are affected. “It is much too early to say, we will only know in a few weeks what is left,” we inform thenational apple pear association. “All regions are not at the same floral stage, and this will also depend on what the different anti-freeze devices have done,” explains Sandrine Gaborieau, communications manager. According to him, this period of spring frost is not exceptional, even if it is feared “at a period of end of flowering when the flowers are vulnerable”. “What is more exceptional this year,” she notes, “is the progress of flowering. »
For Serge Zaka, these freezing nights are in fact nothing exceptional if we compare “the 250 heat records between April 1 and 15”. And the major crop freezes of 2021, 2017 or 1991. The fact remains that the whole thing is an “accumulation of weather events”, which “subject farmers to more uncertain production” and “an accumulation of small yield losses, which can weaken morale and economies.”
May will be cherry time
On the other hand, there is a fruit production which already seems to have passed through the drops, it is the cherry. No major damage has to date been reported in the various production areas in Auvergne-Rhône-Alpes, Occitanie and Paca. “For the moment, the frost episode has no impact,” explains Jean-Christophe Neyron, president of the AOP Cerises de France, who remains cautious as the sector had suffered from the frosts of 2021, he The temperature should not drop a few more degrees below zero.
The cherry blossoms also bloomed a week ahead of schedule. “We are at the small fruit stage, or even more advanced, which allows us to get through the frost,” he says. Even if there may still be unpleasant surprises when the fruit develops, the picking should be beautiful, and the fruits fewer but rounder. “I am surprised this year by the caliber of the cherries,” notes Jean-Christophe Neyron. So, he assures, “there will be cherry, it’s a great year”. It should arrive around May 10 on the shelves.