Environment

Explainer: The threat posed by frost to coffee crops in Brazil

3 minute read

Denis Leonel, the manager of the farm Coqueiro, inspects coffee crops that were affected by frosts as a strong cold snap hit the south of the top Brazilian producer state of Minas Gerais, in Varginha, Brazil, July 30, 2021. REUTERS/Roosevelt Cassio

LONDON, Aug 6 (Reuters) - Arabica coffee prices have surged to the highest level in almost seven years recently after severe frosts damaged crops in top producer Brazil.

Brownish spots have stained large areas of coffee fields in the south of Brazil's top producer Minas Gerais, a sign that the worst cold snap in nearly 30 years will hurt production for at least the next two crops. read more

WHY DO FROSTS POSE A THREAT TO COFFEE?

Frost has posed a threat to coffee trees ever since the crop was first brought to Brazil in the 18th century.

Major producing states in Brazil, such as Minas Gerais, are more frost prone than growing regions in other major Arabica coffee producing countries such as Colombia and Ethiopia.

Coffee is a tropical crop and doesn't like low temperatures, particularly if they dip below 5 degrees Celsius (5°C). Sub-zero temperatures, around -3°C to -4°C (when ice crystals form in the plant's cells) are lethal, destroying flower buds, flowers and fruits, and causing frost burn on leaves, which in severe cases leads to complete defoliation of the coffee tree.

The severest form of damage is due to the formation of ice crystals, which puncture the cells within the affected plant parts, causing them turn black and die, ultimately leading to the death of the plant.

Dr Aaron Davis, who conducts research into coffee at The Royal Botanic Gardens, Kew in Britain, said frost can be particularly devastating after a long period of drought, such as experienced this season, as leaves may have wilted already making them susceptible to low temperatures and frost.

In some cases, it can take one or two years to recover from a frost episode but if the coffee trees die and have to be replaced by seedlings it can take four or five years to get a decent crop and up to seven years to fully restore maximum production levels.

HOW IS THE CLIMATE IN BRAZIL CHANGING?

Research conducted by Refinitiv comparing temperatures and precipitation in the 30-year period from 1959-1988 with 1989-2018 shows the climate in Brazil is on average becoming wetter and warmer.

Extreme cold events are becoming less common but extreme heat is becoming more frequent.

The most recent severe frost was in 1994 and in that case as well there was the devastating combination of drought and frost.

Reporting by Nigel Hunt; editing by David Evans

Our Standards: The Thomson Reuters Trust Principles.

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