Application technology reduced the volume of syrup in orchard treatments and kept citrus farming viable in the country

At the beginning of the 2000s, the technology used to treat the citrus leprosy mite, then the main pest of the crop, required an average consumption of 10 thousand liters to 12 thousand liters of water per hectare, for a population of around 200 plants per hectare. The insect was controlled through the application of acaricides mixed with water, using “pistol” type sprayers, as reported by scientific researcher Hamilton Ramos.

Ramos is today the coordinator of the Reference Unit for Technology and Safety in the Application of Agricultural Pesticides, an initiative that unites the private sector with the Engineering and Automation Center (CEA), of the Agronomic Institute (IAC). Headquartered in Jundiaí, São Paulo, the organization belongs to the Department of Agriculture and Supply of the State of São Paulo. The researcher emphasizes that if the water consumption demanded in orchards had not fallen twenty years ago, citrus farming would have become an economically unviable activity.

According to Ramos, after a series of studies, carried out over 12 years, in a strategic partnership between CEA/IAC and Fundecitrus – Citriculture Defense Fund, the average water consumption in the applications of agricultural pesticides in orchards fell, on the days of today, to 2 thousand to 4 thousand liters per hectare. “The drop in water demand, which is highly representative, is also added to the increase in coverage of the population of treated plants, which jumped from 200 per hectare to 600 per hectare”, explains Ramos.

According to the researcher, the reduction in water consumption obtained in these areas is currently equivalent to the volume needed to supply around 200 million people for one day. “Maintaining the average consumption demanded in orchards in 2000 would make citrus farming economically unviable”, reinforces Ramos. “The culture went through difficult periods, with the advent of diseases such as CVC and greening. This increased plant spraying from 3 to 4 to around 20 sprays annually”, he explains.

Turbo sprayers in the field 

The challenge of reducing water consumption in São Paulo's orchards involved Hamilton Ramos and researchers Renato Beozzo Bassanezi and Marcel Bellato Spósito, from Fundecitrus. It also received support from the companies Cambuhy, Citrosuco, Cutrale, Herbicat and Jacto.

As Ramos points out, around 20 experimental fields were set up starting in 2000. The group analyzed the performance of so-called turbopulverizers in the phytosanitary treatment process of orchards, against pests and diseases. “Initially, there were restrictions regarding the use of this equipment, as in the producers' view, the 'turbo' devices were ineffective in controlling the leprosy mite”, recalls Ramos.

The turbopulverizers, he says, have improved features such as air curtain, number of nozzles, droplet size and displacement speed. The tests covered different models and brands. “The initial evaluation parameters focused on the coverage of the target area by spraying and the amount of agrochemical active ingredient present in the plants, in the high and low points and the depth of the canopy. We also began to measure the volume of plant canopy, to relate it to control effectiveness.”

Ramos highlights the new application technology resulting from the fields allowed the citrus sector to move away from the parameter “liters of water per plant or hectare”, in spraying, to the measure “milliliters of water per m3 of canopy”. Based on the constant improvement of this innovative application technology, he reports, water volumes have been established between 40 ml/m³ for 'external' targets, such as black spot disease, and 100 ml/m³ for internal targets, such as the leprosy mite. .

“This technique continues to advance in studies carried out by Fundecitrus, with work coordinated by researcher Marcelo Scapim. Results for several pests and diseases are now available”, reveals Hamilton Ramos. “The model is also part of the training at the Reference Unit in Technology and Safety in the Application of Agrochemicals”, he concludes.