Sesame cultivation in Brazil grows 230% in one year

Sesame cultivation in Brazil went from 53 thousand hectares in the 2018/2019 harvest to 175 thousand hectares in the 2019/2020 harvest, a jump of 230% in just one year. Production grew 123%, from 41,3 thousand tons to 95,8 thousand tons of grain. In the last ten years, the increase in production has been even more significant, around 20 times more grains than the five thousand tons recorded in 2010. Mato Grosso, especially the municipalities of Canarana and Água Boa, in the eastern region of the state, concentrates the majority of production. 

The increase in the second harvest cultivation area has revealed that the crop still lacks technical subsidies. To meet this demand, Embrapa, the Federal University of Mato Grosso (UFMT) and partners are conducting different research, ranging from genetic improvement to post-harvest.

In one of the ongoing works, sesame samples collected from commercial crops in the 2020 harvest were evaluated with the aim of characterizing the grains produced in Mato Grosso. The analyzes showed that harvest and post-harvest management influence the quality of the product, both in its physical characteristics and in its chemical composition. Furthermore, the use of appropriate equipment can reduce harvest losses.

Samples of different materials were evaluated, including registered cultivars and mixed grains, with mechanized and manual harvesting. In the case of manual harvesting, cultivation is carried out by settled agrarian reform producers, who produce in an agroecological system, with the product destined for the Japanese market. 

Under these conditions, it was found that producers must pay attention to good practices, since electrical conductivity analyzes of the seed soaking solution showed an indication of the presence of fungal spores, causing loss of grain quality. New analyzes will be carried out with the production of the 2021 harvest, seeking to identify the type of contaminants and whether they present any risk to consumption.

“We will carry out antioxidant analyzes and seed health tests to find out which fungal species are present. Fungi that cause mycotoxins are very common in our region with very high temperatures. Mycotoxins could be a problem if the grain is destined for human consumption, but we have nothing measured for now”, explains Embrapa Agrossilvopastoril (MT) researcher Sílvia Campos.

Mycotoxins are a constant concern in the production of Brazil nuts, for example. Research has already shown that good practices in collection and storage are able to avoid the problem.

Harvest losses

Until then, sesame had been cultivated in small areas, with little mechanization. There are still no specific platforms on the market for its harvesting, which is necessary in the case of production in increasingly larger areas. The use of platforms aimed at harvesting soybeans, for example, presents some difficulties, as the differences between size, weight, shape and humidity between the grains cause losses that can reach 50%. 

Adaptations to these platforms, made by producers within the farms, in order to meet the specificities of sesame, are demonstrating effectiveness in reducing losses. Research conducted by professor at the Federal University of Mato Grosso Diego Fiorese showed that on a farm in Campo Novo do Parecis (MT), with two platforms definitively adapted for sesame, losses fell to between 15 and 13%.

The 2021 harvest will be the third in which Diego Fiorese monitors harvest losses in crops in Mato Grosso. According to the professor, the data collected should draw the attention of producers to the lost value and also of regional agricultural implement companies to the feasibility of producing machinery more suitable for the crop. “Doing a rough calculation, with an average loss of 350 kg per hectare, there are R$150 to R$200 million that fail to enter the producers' pockets due to harvest losses”, he estimates.

Fiorese highlights, however, that losses in sesame cultivation begin even before harvest, due to the fact that it is a dehiscent plant (photo on the side), that is, its characteristic is that the capsules (fruits) open when they are ripe. . As a result, many grains fall due to the wind, causing natural loss. According to the professor, on average, 20% of losses are natural, 70% occur on the harvesting platform and 10% in the harvester's internal mechanisms. 

“With our research, we will have guidance on how to reduce harvest losses. But not the complete solution. Everything we see today are adaptations made within the gate. Solutions available on the market should take another three or four years to emerge,” he says.    

Germination index

Another post-harvest characteristic analyzed by researchers in Mato Grosso was the sesame germination rate, since the consumption of sprouts is one of the product's destinations. The results showed that the materials harvested manually had a germination rate greater than 89%. Those harvested mechanically showed a maximum germination of 86%. 

“The cause of this difference may be damage to the seed during harvest. This happens with any grain. Mechanized harvesting hurts the embryo, especially when using equipment that is not the most suitable”, explains Sílvia Campos.

As many producers save their own seed, the lower germination rate also results in the need to use more seeds when sowing the following year.