IAC launches Agrometeorological Bulletin for coffee growing regions in São Paulo

Will it rain? For questions that seem simple and live on people's lips, when it is necessary to have a reliable answer, it is necessary to have a basis in science. And reliable information is what the farmer needs to adopt ideal management at the right time. Because with one wrong step, investments can go down the drain. To provide coffee growers with information about monitoring climatic conditions in different regions of the state of São Paulo, the Agronomic Institute (IAC-APTA), of the Secretariat of Agriculture and Supply, launched the Agrometeorological Bulletin: observed and predicted conditions for the state's coffee trees from Sao Paulo. The monthly online publication was launched in February 2021 and is available on the IAC website (iac.sp.gov.br). New editions can be accessed from the 5th of each month. Those for January/February and February/March are now available.

"This monitoring has been carried out since 2012 by a project coordinated by me, in partnership with Embrapa-Café, and now we have decided to share this information with producers directly and constantly", says the IAC researcher and responsible for the publication, Angelica Prela Pantano. The Bulletin is part of the IAC Climate project and aims to disseminate information relevant to agriculture, reinforcing the fulfillment of the Institute's mission of generating and transferring science and technology.

According to the second edition of the Bulletin, the month of March begins with firmer weather over the coffee growing regions of São Paulo, with the possibility of irregular and low-intensity showers in some regions. "However, already on the first weekend of the month, the tendency is for rain to return to the producing regions in a more widespread manner and with satisfactory volumes", says the scientist.

In general, March should be marked by more frequent rains over the coffee growing regions, from Votuporanga to Franca and Mococa. "The rains may occur almost daily, but irregularly, as they should occur more in the form of showers than winters", he adds. The good news is that conditions are favorable for grain filling and the beginning of maturation.

According to weather forecasts, precipitation volumes for March will be close to climatological normals. This indicates a possible improvement in soil water conditions, meeting needs and increasing soil moisture levels in all regions.

Soil water conditions were better in February than in January

Throughout the month of February, rainfall volumes were below climatological normals in all coffee growing regions of São Paulo, except Espírito Santo do Pinhal. "However, soil water conditions were better compared to January", says Angelica. In the second month of 2021, there was a large variation in volume, which was between 93 mm and 234 mm. "These rains were more intense throughout the first fortnight, some episodes were recorded in the second half of the month. However, in most of the State, the volumes recorded were lower than expected", explains the IAC researcher.

In Votuporanga, it rained around ¼ of the normal volume for February, which would be around 190 mm. The location with the lowest recorded rainfall was only around 52 mm. According to Angelica, the condition of high temperatures and lower-than-expected precipitation led the earliest coffee cultivars to enter the maturation phase. "However, producers who planted new areas are still concerned about rainfall volumes and, in some regions, irrigation has been an alternative to meet needs and reduce water stress", he comments.

The regions of Guaíra and Votuporanga are in a water deficit situation, due to the low volume of rainfall recorded. At the beginning of February, coffee trees were in the grain filling phase and, in some places, at the beginning of maturation. "However, the dry period that occurred in January could harm fruit filling and growth", says Angelica.

In the first edition, information was provided on temperature and precipitation conditions applied to the water balance, which provides soil water conditions. "That's for the previous month. For the following month, we apply the predicted temperature and precipitation data, in preparing the water balance, so that the producer has a perspective of what the soil's water conditions will be like in the next period", says the researcher at IAC, from the São Paulo Agribusiness Technology Agency (APTA). According to the scientist, in January the rains were desired in all coffee growing regions, as the fruits were in the development stage and in need of water.

New areas may have been planted throughout the state of São Paulo. In general, seedlings are transplanted from September to October, counting on the rains from September to March. However, in longer periods with a lack of rain, irrigation is recommended to ensure the growth of these seedlings. "Where this is not possible, losses of seedlings and/or delayed development may occur", says Angelica.

According to the publication, in the period observed from January 1st to 31st, rain was recorded in a large part of the coffee growing regions of São Paulo. The accumulations varied between 200 mm and 250 mm. In general, this volume is considered normal for the first month of the year. "These volumes of precipitation are predicted, however, for some regions, such as Franca, for example, despite being an apparently high volume, it was lower than expected, which resulted in a water deficit condition in the soil", he adds.

However, Angelica reports that these rains occurred mainly throughout the first half of January. In the last ten days of the month, rainfall was very irregular, mainly in the producing regions located in Mogiana, such as Franca, Caconde and Mococa, where accumulated volumes were close to 10 mm. "This drier second fortnight caused a water deficit, which could affect the development of coffee fruits, since they are in the development phase and are close to maturity," she explains. This situation of water deficit and high temperatures contribute to the advancement of coffee tree maturation. In the region of Marília and Garça, in the last days of January, the volumes recorded were close to 20 mm.

Despite satisfactory volumes of rain being recorded across practically the entire state in January, only Campinas and Espírito Santo do Pinhal closed the month with a water surplus. The remaining locations presented water deficits in the third ten days of January.

Initially, the Bulletin will address conditions for coffee growing regions but, in the future, it could be applied to other regions and to other crops such as corn, olives and sugar cane, for example.

Low sieve risk

The researcher comments on the possibility of grain development being harmed by a longer drought. "We may have a low sieve in the next harvest in some crops, as the lack of water during this period of fruit development leaves them smaller, damaging the quality of the grain and even the drink", she warns.

Rainfall volumes have been lower than predicted. According to the IAC researcher, in the state of São Paulo, generally in the months of January, analyzing rainfall data over a period of 30 years in accordance with climatological standards, it is observed that normally rainfall volumes vary from 200 to 300 mm . "This does not mean that it will occur every year, it is what we call climate variability, in some years it may rain above and in others below expectations, in others it may be close to this volume", she explains.

Climatic conditions vary between locations, periods and also from one year to the next. "Forecasts can help us in the management of agricultural activities, but they are forecasts, made using agrometeorological and mathematical models, and suffer from constant variations in the weather, such as the arrival of cold fronts, convergence zones, wind and others. ", account. Models are tools that must be used daily, so that atmospheric variations are permanently computed and taken into account to generate forecasts.

In this work, IAC partners are Rural Clima and the Agricultural Research Support Foundation (Fundag). Rural Clima is a company specialized in weather forecasting for agricultural areas, operating throughout the national territory. The partnership takes place through a project financed by the Café Research Consortium, coordinated by researcher Angelica Prela Pantano, with the collaboration of the visiting researcher linked to the IAC, Ludmila Bardim Camparatto, and the agrometeorologist and company owner, Marco Antonio dos Santos.

According to Angelica, this project is an upgrade from previous projects, when climate monitoring was carried out in the coffee growing regions of São Paulo. "Over the next four years, with the collaboration of Rural Clima, we will combine monitoring with climate forecasting, which made it possible to implement this bulletin", she comments.