Epagri launches affordable solution for irrigation against frost

Professionals from Epagri/Ciram developed and installed a low-cost device capable of measuring the flow of water sprayed on peach orchards for frost control. The installation took place in February, at Epagri's experimental field in Videira. 

Frost can compromise entire orchards of stone fruits, such as peaches and plums. To protect these plants from the intense cold, they need to be frozen. This technique is called sprinkler frost control. The equipment developed by the Epagri/Ciram team is capable of determining the flow rate of the sprinkler irrigation system to quantify the amount of water to be applied during the occurrence of frost.

Guilherme Miranda is the Epagri/Ciram researcher who developed the equipment and coordinated its installation. He explains that, in addition to being low cost, the instrument is easy to manufacture and offers accurate measurements. “With the information collected by the agro-meteorological monitoring stations installed in the experimental orchard, we will be able to quantify whether the sprayed volume is sufficient or not to combat frost,” he explains.

According to the Manager of the Epagri Experimental Station in Videira, researcher André Luiz Kulkamp de Souza, the equipment will enable cost reduction in irrigation. It will also assist in the rational use of water, increasing the environmental sustainability of the production chain. 

Iria Sartor Araujo, a researcher at Epagri/Ciram and coordinator of the research, reports that “there is a lot of literature on the subject in other countries, but for the climate conditions in Santa Catarina, we do not have technical parameters that have been studied and adapted to reality to help our farmers combat this high-frequency meteorological phenomenon in the winter in Santa Catarina”. She emphasizes that conducting the research enables the development of technologies applied to the needs of rural producers in Santa Catarina. 

The research coordinated by Iria seeks to validate the technology for automatic telemetric monitoring of orchard temperature and other environmental variables, such as relative humidity and leaf wetness. The experiment is being developed in the peach orchard located in Epagri's experimental field in Videira. 

Improve decision making

The ultimate goal is to deliver to the fruit grower's cell phone, tablet or computer the information needed to facilitate and improve the fruit grower's decision-making regarding the need for spraying to combat the effects of frost in the orchard, while also making their work less arduous. This is because, without transmission technology, the producer has to brave the cold to go to the orchard in person to check the temperature measured by thermometers installed in the plants. The technology will also help to increase the productivity of the orchards.

In the initial stages of the research, temperature sensors were installed at different heights in the peach tree canopy. Last winter, during a moderate frost event, the Epagri/Ciram researcher remotely monitored the information generated by the sensors. In the experiment, the temperatures measured by the sensors were transmitted via e-mails sent every hour to cell phones and computers. Each e-mail contained the temperature measured every five minutes in that last hour. The technology will allow farmers to control this variation from the comfort of their homes, activating the sprinklers in the field when the temperature reaches 1°C. 

Understand the technique

In the frost control technique by sprinkling, the fruit grower needs to remain alert when the weather is favorable for frost. When the ambient temperature reaches 1°C, with a tendency to fall, it is time to turn on the sprinklers. The idea is to create a good layer of water over the plants so that they freeze when the temperature reaches 0°C and remain that way until the air temperature returns to positive levels.

André Kulkamp de Souza explains that damage begins to appear in fruits when the temperature reaches -1°C. In the case of flowers, the minimum temperature they can withstand is -3°C. When the plant is completely frozen, it remains at a temperature of 0°C, regardless of how cold it is in the environment, and this way, production losses due to frost are avoided. 

Epagri is a pioneer in Brazil in the study and recommendation of the use of frost control technology by spraying. The Epagri Training Center in Videira began testing in 1983, in peach orchards. Epagri offered courses that disseminated the technology, currently used in several regions of the South of the country. 

The installation of the low-cost flow meter was carried out in February by the Epagri/Ciram Agro-Environmental Monitoring team, consisting of research assistant Roberto Carlos Silveira and meteorology technician Rafael Ataide de Araujo. They were supported by Adelar Rech and Roberto Bolzani, from the Epagri Experimental Station team in Videira.