Ordinances No. 19 to 49 were published in the Brazilian Official Gazette of this Wednesday and Thursday (14 and 15), dealing with the Agricultural Zoning of Climate Risk (Zarc) of the citrus culture. This is the first zoning for citrus cultivation that considers climatic risks of 20%, 30% and 40% for orchards in production and for the implantation of new areas and not only the climatic aptitude, as was done previously.

Zarc is an agrometeorological study that indicates the climatic risks for various agricultural crops in different regions of the country. It is used, for example, by financial institutions to assess credit and rural insurance, since it provides information on the chances of success for each crop depending on the location and the time it is planted.

Developed by Embrapa in 1996, the tool also supports public agricultural development policies. The results of the study show in which municipalities it is possible to produce within the accepted risk levels (20%, 30% and 40%). For the implantation of the orchard, the results show where and when it is possible to plant seedlings with less risk.

The new Zarc Citros innovates by covering the groups of orange, lime, lemon (acid lime ‘Tahiti’), mandarin and grapefruit. A novelty is its expansion to the entire national territory, including citrus fruits with different production cycles - early, mid-season and late.

“There are differences in the duration of the development phase of fruits of the same variety depending on the region analyzed, mainly due to differences in air temperature during this period. This explains the importance of the approach taken, with different production cycles. So, we have early orange trees with 180 days in Bahia, and the same orange trees with 200, 220 days or more in some regions of southern Brazil ”, explains agronomist engineer Maurício Coelho, a researcher at Embrapa Mandioca e Fruticultura (Cruz das Almas, BA) and coordinator of Zarc Citros Brasil.

For the first time, the study also takes into account risks associated with the stages of fruit development, from flowering to fruiting to harvest.

“Flowering and the beginning of fruiting, for example, is a period of greater sensitivity for the crop. Extreme temperatures, low air humidity and water deficit in the soil can cause excessive fall of flowers and fruits and possible losses of production, being elements that must be considered in the assessment of climatic risk for the crop ”, observes Coelho.

This occurs mainly in regions with strong floral induction by the cold in winter. In this environment, annual blooms are concentrated in the months from September to November, when there are still high risks associated with the deficit of water in the soil, higher extreme temperatures, low relative humidity of the air and, in the South of Brazil, some regions with risks of occurrence of frosts (mainly in September).

In addition, the zoning results showed that, predominantly, there were production limitations related to the water deficit, generally in the regions of the cerrado and caatinga biomes, where the risks of plant mortality and drastic production losses are high.

The researcher José Eduardo Borges de Carvalho, moderator of the validation meetings in the North, Northeast and Southeast regions of Brazil, considered the experience quite positive. “I was able to observe the great interest of researchers, consultants, producers and rural extension agents on the subject, providing an excellent final product. At the meeting in the North region, for example, it was suggested that Zarc should take into account the excess of rain, which often imposes the displacement of soil preparation and planting periods in relation to the most suitable ones ”, he comments.

“Using this tool, the producer can better prepare crop management to improve plant production and productivity. This platform brings more security to the agricultural business in Brazil's citrus hubs, quantifying the climatic risks involved in conducting the orchard that can cause losses in production ”, he highlights.

For Vinícius Trombini, coordinator of the Crop Estimation Survey of the Citriculture Defense Fund (Fundecitrus), “Zarc is valid because it reduces the risk of investing in an agricultural crop that may not be the best adapted for the region”. Trombini attended the validation meeting in the Southeast, South and Midwest regions and approved the event. "I think the idea of ​​having a wide participation of several researchers was assertive," he said.

The Zarc study is published in ordinances for each state considering rainfed cultivation. For perennial fruit trees like citrus, Zarc is divided into two studies. The first to assess production risks, which is based on the characteristics of an established orchard and the needs of the crop to produce satisfactorily. The second assesses the risks for implanting the orchard, considering