Risk of frost makes producer use molasses, smoke and amino acids to protect crops

To try to reduce potential damage caused by the frost forecast for this week, producer Beatriz Sabino Almeida, 29, has already separated lots of molasses to help heal the cabbage she plants in Mogi das Cruzes.

Like her, rural producers in São Paulo have used recipes and developed techniques to protect crops from the frost expected in some regions of the state due to the advance of the intense polar cold wave that has caused snow in the South and lowered temperatures.

In the most varied cultures, producers adopt metal tanks with sawdust and oil to make smoke and try to reduce the intensity of frost, while others throughout the year bet on strengthening the plant so that it can withstand low temperatures and frost. The climatic phenomenon of July last year generated losses of 40% in one of the coffee regions of the state.

“We try to protect, but there are things that we can’t. What I produce is in the soil, open planting, different from those who adopt hydroponics. Some vegetables even resist, but they go into a state of stress, they stop bearing fruit”, said Beatriz, who produces kale on less than half of the family’s two hectares (20,000 square meters).

To protect the cabbage, he also prepared molasses, with the aim of healing the plant. “It comes in with this function, as if it were a curative medicine. It can be used all year round, but when it happens in frost it’s quite useful. I’m worried about the frost, but I’ve heard it won’t get here.”

In the case of leaves, the damage is more visible and commercialization is often completely unfeasible also because the plants are burned. The tomato, in turn, has its maturation delayed with the cold. In coffee, the frost aborts the development process and the fruit does not set.

One of the regions of the state that may suffer from frost is Franca, a strong coffee producer, which had losses of 40% due to the frost that occurred in July last year.

“There are producers using smoke to try to help, but I don’t use it because I don’t think it solves it. In this pre-frost, which we hope it doesn’t come, I use some products that were launched on a field day two weeks ago. It makes a layer of protection in the coffee so that it doesn’t sweat during the cold”, said coffee grower José Henrique Mendonça, president of the Rural Union of Franca.

According to him, however, it is not even necessary for there to be frost to cause damage to the coffee plantations. “When the temperature is below 10ºC, it already interferes with production. The productive bud causes an abortion. It opens flowering, but the fruit does not set. In 2021 we lost 40% with frost due to these problems as well.”

As the possibility of frost approaches, good practice measures are being shared by associations and research centers. The first, simpler, included the cancellation of irrigation this Tuesday (17).

Another suggests that the farmer mix hydrated lime with wood ash, dilute the mixture in hot water, add cold water, filter and store the resulting solution. The syrup is then diluted in water and sprayed on crops to be protected up to four hours before frost.

VALID ALL YEAR

Persimmon producer in Mogi das Cruzes, Ercilio Hoçoya is in the middle of harvesting and has not been able to prepare anything specific for the frost, but he has adopted the use of amino acids throughout the year to generate energy for the plant, so that it can resist the sensation more thermal.

“It won’t save, but it minimizes the loss, so the plant doesn’t feel too much. As the crop is perennial, a frost can harm future crops. With amino acids, I can lose part of the production, but I preserve the plant.”

He ruled out using smoke, a technique he had already adopted in previous years and said it had not given satisfactory results.

Producer and founder of #FaçaumBemINCRível, which organizes food donations for needy communities, Simone Silotti said that the cold impacts the vigor of even plants in greenhouses.

“One that was supposed to be ready in a few days ends up demanding another week. It affects the entire chain, such as labor, inputs, planting and harvesting, which means that not only productivity but also profitability falls,” he said. she, who produces lettuce, watercress and arugula in greenhouses.

A Cepea researcher on lettuce, onions and carrots, Marina Marangon said that the leaves must be the most affected by frost, both those that are about to be harvested and those that are still in the development phase.

“The frost can harm in several ways, but the main thing is that it can burn the leaf, which will end up being discarded. It won’t cause disease, but it will burn and then it won’t develop”, he said.

In the last week, the beginning of the arrival of the cold caused a reduction in the consumption of leaves, bringing down the commercialization, according to Cepea.

In Mogi das Cruzes, the price of a box with 20 units of iceberg lettuce rose 2.64%. The expectation is that, in the coming weeks, there will be a new increase in prices, motivated by the retraction of investments due to the high production costs.

This forecast will depend on the impact that the frost will eventually have on the gardens. “If the frost is strong, the impact can be high, yes. I believe that in hardwoods we have a very high price level, higher than usual. Producers don’t have much money to invest, so they already have a lower production level . A frost could impact and prices could rise even more.”

For USP (University of São Paulo) professor Marcos Fava Neves, a specialist in agribusiness, all crops in progress are heavily threatened by frost.

“We are dealing with many climatic events, a worrying thing in this serious moment of stress, of lack of products, the climate playing its tricks”, he said.