Research uses forced air in onion storage to reduce losses caused by bacterial rot

Research by Epagri recorded a reduction in onion bulb losses caused by bacterial rot when the storage of this vegetable uses forced air instead of natural ventilation. Especially in rainy years, the disease has a major impact on the crop, with average losses estimated at 20%. This causes an average annual loss of R$180 million for agriculture in Santa Catarina.

According to researcher at the Epagri Experimental Station in Ituporanga (EEItu) and study coordinator, Renata Resende, bacterial rot in onion bulbs is an obstacle to storage. “Post-harvest losses are often attributed to failures in the curing and storage process. Forced air ventilation during storage, in addition to facilitating the curing process, stabilizes the temperature and relative humidity around the bulbs, which contributes to reducing losses,” she explains.

Longer post-harvest life

According to Renata, the storage stage is crucial to maintaining the quality and longevity of the onion. “The search for more efficient types of storage is important, as it allows the producer to increase the post-harvest life of the onion and scale up the sale of the product”, highlights the researcher.

By reducing post-harvest losses, farmers can maximize their income and contribute to regional food security. “In addition, minimizing food waste has significant implications for the conservation of natural resources and the mitigation of environmental impacts associated with agricultural production”, adds Renata.

The research was carried out during three consecutive harvests, between 2021 and 2023. The objective was to evaluate the losses caused by bacterial rot in onion bulbs subjected to the storage systems most used by family farmers in Santa Catarina. The study was carried out in Ituporanga, Aurora, Vidal Ramos and Alfredo Wagner. The project had the collaboration of researchers from EEItu and rural extension agents and farmers from the aforementioned municipalities.

Onion in SC

In Santa Catarina, onions are the vegetables with the highest gross agricultural production value (VPA). According to Epagri/Cepa, in 2023 the VPA recorded was R$938 million. The state is the largest national producer, responsible for approximately 1/3 of the total planted area in the country (more than 18 thousand hectares) and 1/3 of national production (approximately 500 thousand tons/year).

In addition to the economic aspect, onion cultivation plays an important social role. The vegetable is grown, almost entirely, by family farmers, with more than 8 thousand families directly involved in the activity.