August 1, 2019

How Coffee Producers Can Prepare For Unexpected Weather


In early July this year, Brazil’s coffee-producing regions were hit by frost. Coffee crops were in harvest, but it’s expected that the weather conditions will have some impact on next year’s production numbers. When frost hits, there’s little you can do to protect your crops. But there are ways to prepare for other unexpected weather conditions.

Read on to learn more about how to plan for and handle unexpected rain and drought.

Lee este artículo en español Caficultores: Cómo Enfrentar Eventos Meteorológicos Inesperados

A view from a coffee farm in Honduras. Credit: Perfect Daily Grind

The Effects of Unexpected Weather Conditions

Keith Pech is Sales and Export Manager at Damarli Estate, in Boquete, Panama. He tells me that ideal weather conditions there are “distinct and clear, rainy from April to November and a dry season from December to March”. Geisha is a popular choice of crop in this region. 

Keith tells me that he has often experienced unexpected weather conditions and that the most damaging is “when after the dry season and harvest, rain comes but then leaves, causing flowering and the trees to lose fruit”. He says that rain causes the fruit to take on moisture, which makes the cherries heavier and they drop to the ground. “The end result is less coffee, causing growers to charge more or take serious losses if they sell at normal market price,” he says.

He also highlights the increased risk of pests and diseases from unexpected weather conditions, saying that “if the weather switches between rainy and dry, roya [coffee leaf rust] becomes a huge issue.”

Learn more in How to Monitor For & Prevent Coffee Leaf Rust

Coffee flowers. Credit: Fernando Pocasangre

Francisco Guimarães produces coffee at Fazenda Lavrinha in Minas Gerais, Brazil. He tells me, “One of the most critical factors related to weather conditions is high temperatures while the coffee is flowering or in fruit development, especially when these high temperatures are combined with low soil moisture, which can produce severe water stress.”

“When these conditions occur during flowering, the risk of abortion is greatly increased and the amount of fruit is reduced, resulting in overall lower productivity. If these conditions occur during the fruit growing phase, it can affect weight gain and product quality. It can result in smaller fruits with lower value in the market,” he says.

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A coffee picker at work. Credit: Perfect Daily Grind

Francisco tells me that in addition to high temperatures and lack of water, his crops are at risk of damage from other weather events. “There is a risk of hailstorms in this region, which can cause serious crop damage such as defoliation and fruit drop,” he says. 

Like Keith, he mentions the increased risk of pests and diseases that comes with unexpected weather conditions, telling me that because hail damages plants, it can allow easier infection with bacterial diseases.

“We recently lost about 2,000 bags of coffee due to a hailstorm causing damage to the crop,” he says. “In the winter, frost can occur, which in the most extreme cases destroys the whole crop. In this event, pruning is necessary and production can be stopped completely.”

A view from a coffee farm in El Salvador. Credit: Fernando Pocasangre

Unexpected weather events don’t just affect crops in the fields. Coffee quality is at risk even after harvest if a sudden shower or change in temperature occurs. Cherries drying on patios are at risk of fermentation of fungal infection from an unexpected rain or cooler period.

Bruno Ribeiro is a consultant in coffee quality in post-harvesting. He says “a producer’s coffee estate is an open-air business. Thus, the unexpected is always likely to occur. Producers and their collaborators should seek production techniques that minimize risk of loss in coffee quality.”

Damaged coffee cherries at a farm in São Manuel, São Paulo, Brazil. Credit: Ivan Laranjeira Petrich

Safeguarding Against Unexpected Weather Conditions

So what can you do to reduce the risk of damage and reduction of quality?

  • Plan Ahead

If you have an established farm, it’s unrealistic to move your crops. But if you’re setting up new plantations, make sure to consider the land conditions. Avoid low ground, where water can pool during heavy rains. This can increase the risk of pests, root rot, and fungal infections.

You should also consider planting large trees around your crops to serve as a wind barrier. This can protect the coffee during storms and also guard against the spread of coffee leaf rust.

Bruno says to keep an eye on the weather, by regularly checking online or watching TV forecasts. If you know there is an unusual weather event coming, you can be better prepared.

He also says that it’s important to have the correct tools and materials on hand, suggesting that you should “have harvest cloths and tarps to cover your coffees on your property” as well as sanitizers that are suitable to apply to coffee.

A coffee plantation in Brazil. Credit: Julio Guevara

  • How to Handle Heavy Rainfall

Too much groundwater can cause root rot and put plants at risk of fungus and bacteria. If it’s unusually wet, check for pooling around trees and create irrigation channels if necessary.

If it rains during harvest, cherries are at risk of swelling and falling to the ground. Keep an eye on forecasts and try to get ahead of any downpours with additional pickers if needed.

Set up drying patios on a slope if possible – this way, if they do get unexpectedly rained on, at least the coffee won’t sit in water. Retractable roofs or covers are a good way of further minimising exposure to rain. If they are out of budget, tarps work too.

But coffee under covers is still at some risk. Bruno says, “If the rain is prolonged, depending on the post-harvest process adopted, the batch may have quality losses under cover.”

Natural processed coffee drying in patios. Credit: Fernando Pocasangre

Francisco tells me that when sporadic rainfall occurs, his farm uses mechanical dryers. They are an investment, but can speed up drying and even save a crop during an unexpectedly rainy season.

Keith suggests that, if all else fails, you could consider moving the crop. He says, “I know a farmer who had a huge rain problem and couldn’t dry coffee if his life counted on it. He had a friend who had a free patio an hour away that did not have rain issues. He moved his coffee there to dry and successfully saved his crop!”

Damaged cherries at a farm in Brazil. Credit: Julio Guevara

  • How to Deal With Drought

Water is a key element of any farm. Without access to enough moisture, coffee plants won’t produce fruit. Keith tells me that if there isn’t enough rainfall during planting, young trees will die. And if a dry period continues too long after flowering, the tree will shed its buds, resulting in a bad crop. He says that rain is very important during the fruit formation stage.

Irrigation systems are an efficient way of making sure all of your crops receive enough water. Francisco says that “Fazenda Lavrinha has four drip irrigation projects in the coffee crops. These systems have high efficiency, which, combined with a management program, can achieve high productivity with sustainability, optimizing water and energy resources.”

He tells me that through a climate monitoring system, he knows that two precipitations occurred in August, when coffee was pre-bloom. “Then there was a period of 37 days without rain with increasing temperatures. This is a very critical period for the coffee and, in this case, the use of irrigation with a management system was fundamental to avoid reduced yield.”

You may not be able to afford a full drip irrigation system and climate monitoring, but surface irrigation can be more affordable. You can also install water butts throughout the farm to catch rainwater for use during dry spells.

Coffee drying in a covered patio in Brazil. Credit: Ivan Laranjeira Petrich

If your crops are hit by an unexpected weather condition, it can be stressful and demoralising. In this era of climate change, it’s likely that you’ll have to deal with some climactic surprises. But there are ways to minimise the impact. 

Keith says, “Be creative, know what issues can arise from bad weather and have a Plan A, Plan B, and Plan C. Make friends and don’t isolate yourself.”

Bruno tells me that “coffee cherries are fruits with active metabolism, post-harvest processes, fruit moisture, ripeness, drying temperature [can all be affected by weather]. You did your best; wait for the result.”

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Interviews with Bruno Ribeiro and Francisco Guimarães translated from Portuguese by K.J. Yeung and Hazel Boydell.

Perfect Daily Grind

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