Ministry of Agriculture includes onion in Climate Risk Zoning

Onion cultivation (Allium cepa L.) represents the first vegetable included in the National Agricultural Zoning Program for Climate Risk (Zarc) for all producing regions in the country. The ordinance was published in the Official Gazette of the Union (DOU) by the Ministry of Agriculture and Livestock (Mapa), this Friday (09). The studies that supported the creation of the Ordinance were coordinated by Embrapa Hortaliças (Brasília – DF) within the scope of the Zarc Network with the support of the ministry.

Zarc delimits areas and times of low climate risk for the implementation and production of crops in Brazil. Embrapa Hortaliças researcher, Marcos Braga, reinforces that the objective is to subsidize producers with information about agro-climatic risks, with the aim of reducing production losses and obtaining higher yields.

The onion Zarc results cover all producing regions and summer and winter plantings, including rainfed and irrigated crops. Due to the diversity of cultivars and planting cycles, which vary according to the region and planting time, Zarc classified tropical and temperate cultivars into seven groups and considered average production cycles, according to the average cycle length and the phases of interest, for risk assessment.

By following the recommendations included in Zarc, farmers are less subject to climate risks and can also benefit from the Agricultural Activity Guarantee Program (Proagro) and the Rural Insurance Premium Subsidy Program (PSR). It should also be noted that many financial agents, if there is Zarc for culture, only release rural credit for crops in zoned areas, this is the case of medium producers who access the National Support Program for Medium Rural Producers (Pronamp).

Onion cultivation in Brazil

Onion is the most widespread seasoning vegetable in the world, being a basic ingredient in almost all Brazilian dishes. Production is mainly concentrated in the South region and in the states of São Paulo, Minas Gerais, Goiás, Bahia and Pernambuco, responsible for around 95% of the country's production.

On a global scale, Brazil currently occupies 13th position with production stabilized at around 1,6 million tons per year. Due to the size of the territory and the diversity of the climate, it is possible to have several onion crops throughout the year. Production is concentrated between March and November in most of the main producing regions, and almost exclusively supplies the domestic market. In the Northeast region, mainly in the States of Bahia and Pernambuco, onion cultivation occurs throughout the year.

As it is a crop present in all Brazilian regions, the researcher makes the following reservation: “it is essential that producers only use tested and recommended cultivars for each location and time of year, always based on technical guidance from assistance companies and of rural extension qualified in the area”.

Risk assessment criteria

Another issue, which deserves the attention of producers and poses a high risk to the crop, is related to cultivation in areas that have already had the occurrence of white rot (Stromatinia cepivora Berk.sin. Sclerotium cepivorum), considered one of the main diseases in onions as it causes total production losses.

Braga adds that onion cultivation is greatly influenced by weather conditions. Water availability, photoperiod (number of hours of daily light), temperature and rainfall are the main elements that, in unfavorable conditions, result in the risk of production loss. Due to the crop's high sensitivity to lack of water, cultivation is almost exclusively irrigated.

Very few regions allow dry farming due to the high risk of water deficit. The researcher also explains that the photoperiod and temperature are the climatic factors that control the formation of onion bulbs and this limits the recommendation of the same cultivar for several producing regions, which are in the South, Southeast and Northeast of Brazil.

Due to these factors, the onion cultivars available for planting in Brazil are categorized into two groups: short days – which bulb with at least 12 hours of daily light; and intermediate days - which require 13 or more hours of light per day. Therefore, the correct choice is very important, as the use of the wrong cultivars for a given location and time will result in low productivity, which may be accompanied by poor quality of the bulbs.

In Zarc, the planting dates (decennials) in municipalities favorable for onion cultivation were classified according to the level of climate risk of 20%, 30%, 40% based on the following criteria:

- Severe water deficiency when not reaching the minimum limit of the water needs satisfaction index (ISNA), in a rainfed system;

- Very low temperatures that are harmful to the crop due to the probability of occurrence of minimum temperature values ​​lower than or equal to 11°C;

- Very high and harmful temperatures for the crop due to the probability of maximum temperature values ​​exceeding 34°C;

- Excessive rain or excess water harmful to the crop through the probability of accumulated precipitation greater than 130mm in the final stage of maturation and at harvest;

- Excess rain or excess water through the probability of occurrence of accumulated precipitation greater than 150 mm, in the crop implementation phase when done through direct sowing or planting seedlings;

- Excessive rain or excess water due to the probability of occurrence of accumulated precipitation greater than 210mm, in the crop implementation phase when done using bulblets.

Partnerships

The development of the onion Zarc included a multidisciplinary team made up of specialists from Embrapa Hortaliças, Embrapa Digital Agriculture, Embrapa Clima Temperado, Embrapa Semiárido, Agronomic Institute and the Agricultural Research and Rural Extension Company of Santa Catarina. Online meetings were also held with farmers from the main producing regions.

Where to find the results

Zarc's national studies meet the objectives of the National Agricultural Climate Risk Zoning Program. Compliance with the planting dates recommended by Zarc is mandatory for producers who wish to access the Agricultural Activity Guarantee Program (Proagro) and the Rural Insurance Subsidy Program (PSR). The onion Zarc results are available on the Map in the Indicator Panel and in the Zarc Plantio Certo app (IOS, Android).