Drought and cold threaten corn production in Paraná

The lack of regular rainfall and the arrival of winter have caused concern among corn producers in Paraná, especially given the risk of frost and sharp drops in temperatures in the coming weeks. According to the National Institute of Meteorology (Inmet), the forecast for early June indicates the possibility of frost in areas of the Southern Region, including Paraná, due to the arrival of a cold air mass that will cause a sharp drop in temperatures. In addition, accumulated rainfall in recent weeks has been below the historical average, worsening the situation for crops. These adverse weather conditions can compromise plant development and negatively impact crop productivity.  

According to Alexandre Luis Muller, professor of Agrometeorology at the Pontifical Catholic University of Paraná (PUCPR), Toledo Campus, irregular rainfall has directly affected corn crops in the state. In Paraná, two main types of precipitation predominate: convective and frontal. Convective precipitation is isolated rain, typical of summer. Frontal precipitation is associated with the arrival of cold fronts and usually covers a larger area. According to the professor, the last significant occurrence of frontal rain was recorded in December 2024, and since then, only isolated showers have hit the state, insufficient to meet the needs of crops.  

Muller warns that, although rain is desired by producers, its arrival at this time of year can pose an additional risk. “To replenish the necessary moisture in the soil, a high volume of rain would be needed, which could be accompanied by a sudden drop in temperature, increasing the risk of frost soon after,” he says. 

The lack of rain has caused producers to invest less in crops, such as in disease treatment. “Many producers have chosen not to invest in phytosanitary management due to the expectation of losses, which has created yet another challenge for the harvest, which is now suffering from greater disease outbreaks,” says the professor. 

Although there is still no confirmed forecast of frost, the possibility is already a concern. “If a frost occurs now, a large part of the crops would suffer significant losses,” warns Muller. 

PUCPR has a weather station that monitors precipitation levels, maximum and minimum temperatures, wind speeds and relative humidity. This data is used both in academic projects that assess the impacts of environmental conditions on crops and in the preparation of meteorological reports for the region. “Climate predictability helps producers plan activities, from defining the sowing season to making decisions for management,” emphasizes the professor.