Due to the exceptional climatic conditions, France produced only 29.3 Mtof wheat in 2016, compared to the average of 38.8 Mt over the previous 5 years (1).
Indeed, it is recognized that climatic hazards impact agricultural production in quantitative terms. This impact is easily measured by the final crop yield. It has long been recognized and is the subject of protection, such as strategic stocks (2) and insurances.
However, this aspect of climate-related losses remains reductive, and thanks to the 3 examples below, this article will highlight the impact of climatic hazards on the quality aspect of agriculture production.
We will discuss the qualitative impacts in wine production, aesthetic aspects in arboriculture and the risks of toxins in cereals.
The grape and wine production:
During vinification (transformation of the grape into wine), the winegrower seeks to obtain a wine typical of his production to meet the tastes of his customers. Particularly, in France, this typicality is guaranteed by the specifications codified in “AOC” – “Controlled Designation of Origin”- (grape varieties, practices, alcohol content, etc.), such as “AOC Bordeaux “(3). But the strict rules associated with obtaining this AOC label come up against the impact of climate change on winemaking processes. The rise in temperatures leads to an earlier maturity, a higher sugar level and, precisely, an alcohol level which increases by around 1 ° per decade for the red grape varieties (4) and 0.6 ° / decade for the Cognac’s wines. (See Image 1)
Image 1: Evolution observed since 1978 of the average alcoholic strength in the cognac vineyard ORACLE Nouvelle Aquitaine – Data: BNIC – Extract from: 5èmes assises des vins du Sud Ouest, Frédéric LEVRAULT, January 17th – 2020 -TOULOUSE (a)
The risk then is for the winegrower to leave the standard tastes of his customers and lose market share. (5)
Likewise, climatic hazards (low and high temperatures, rainfall) influence flowering, leading to significant flower abortion and / or millerandage (6) (7) (See Image 2 and 3). The latter phenomenon is when the grape bunches grow with very heterogeneous ripe grains and differ greatly in size, which depreciates the table grape (grape meant for eating purpose and not for wine) and needs a more complicated and more qualitative vinification.
Image 2: “Coulure” : A lot of aborted grains (b)
Image 3: “Millerandage”: partial abortion, with grains that are very heterogeneous size and maturity (c)
The Arboriculture:
Considering the importance of the conservation and the “beauty” of fruits in the fresh market, damage caused by hazards can also have a very strong impact on the depreciation of the production. For example, frost creates spots and deformities, hailstones impact and cause fragilities, and drought causes a reduction in the size of the fruits which are then downgraded. (See Image 4 and 5)
Image 4: Frost ring developed on the fruits Giraud M. (CTIFL) (d)
Image 5: Apples riddled with hailstones ©-Radio France – Noémie Philippot (e)
Eventually, the farmer has a double loss: a loss of yield and a significant loss of value for the remaining production. The latter is refused (thrown away) or redirected towards the industrial processing market. For example, in apple production, the selling price drops from 1000 – 2500 €/ton for fresh market to 300 – 400 €/ton for industrial purpose. (8)
The Cereal Production:
The risk of toxins in cereals, and especially DON (deoxynivalenol), is a significant risk for humans (vomiting, inflammation of the skin, attack of the liver and digestive tract, drop in the number of blood cells; death for extreme cases) and animal food. Thresholds are specified at the European level (9) depending on use (see Table 1).
DON are thermostable mycotoxins (not destroyed by cooking) produced by fungus (Fusarium spp). However, the development of this fungus is strongly correlated with the weather conditions and studies also seem to suggest an increased risk due to climate change (10). The risk is therefore higher of having, not only of significant losses in yield (sometimes >2 t/ha), but also of seeing the rest of the production refused for purchase because it does not comply with regulations.
Table 1: Maximum level of DON authorizedin food Extract from the Europeanregulation (9), page L364 / 17
In conclusion:
Here we have detailed 3 examples, but in many cases we must be aware that the farmer, during a climatic hazard has the risk of suffering a “double penalty” which on one hand is a loss of yield, and on the other hand, a loss of quality of the remaining production. The latter can be significantly important, according to the desired outlet.
The question therefore remains: “How to protect farmers and balance between a known additional cost of protection and qualitative losses which are still too often subjective?”
