The Three Sisters: Optimizing the value and food potential of an ancestral indigenous crop system

Set up an interview

Media Relations
Agriculture and Agri-Food Canada

In a number of Indigenous communities, corn, squash and bean are called the "Three Sisters." When planted side by side, these three crops help each other during growth, resulting in better yields at harvest. The Three Sisters crop model, were once widely used by a number of First Nations in the Great Lakes –St. Lawrence Lowlands region. Research scientists at Agriculture and Agri-Food Canada (AAFC) and the members of the Indigenous communities became interested in working together to better understand the model and why it was so successful. Optimizing the value of this model could offer Indigenous communities food and business opportunities that are connected to their traditions, while also providing an effective and sustainable method for preserving biodiversity on cropland.

Experts from a number of organizations at AAFC, Laval University and the University of Ottawa worked with collaborators from the Haudenosaunee and Huron-Wendat Nations to successfully carry out the Three Sisters project. The goal was to explore the potential of Three Sisters cultivation on a larger scale within communities as well as to gather informed data for assessing the value of the Three Sisters for the production of niche Indigenous food products.

The research was guided by three themes:

  • Preserving seeds and protecting Indigenous rights and knowledge
  • Cultivating the Three Sisters in the Indigenous manner and characterizing their properties
  • Evaluating the food potential of the Three Sisters in niche products

Ancestral seeds are a scarce resource. In Indigenous communities, seed keepers are responsible for saving seeds after each harvest for future use. Because a number of seed varieties are not commercially available, seed keepers are the custodians of highly valuable plant diversity that is perfectly suited to the Canadian climate. That is why one of the research teams focused on legal rights surrounding ancestral knowledge. Measures were taken to protect the rights of the owners of the seeds shared for this project.

Cultivating the Three Sisters

With a view to cultivating the Three Sisters, a team evaluated the agronomic potential of some thirty ancestral varieties of corn, squash (pumpkins) and beans that had been bought on the market or received from Indigenous collaborators. For three summers starting in 2015, the varieties were grown on the Saint-Jean-sur-Richelieu Research and Development Centre’s L’Acadie Experimental Farm.

"I was in charge of gathering essential agronomic knowledge from Indigenous collaborators and Jardins de l’Écoumène [an artisan organic seed grower in Quebec] to find out how to grow the Three Sisters varieties that we had, in a manner based directly on the Indigenous model. Thanks to preliminary monoculture trials (where the crops were grown individually) followed by polyculture trials (where the crops were grown together) without chemical inputs, we were able to produce enough fresh products to supply the research scientists involved in the project."

– Carl Bélec, biologist, Knowledge Technology Transfer Office, Agriculture and Agri-Food Canada

In cultivating the Three Sisters in a manner as close to the traditional method as possible, AAFC wanted to ensure that the fresh products harvested and used by its research scientists were similar, in terms of both the production method and the varieties that were used, to what Indigenous communities would be able to obtain themselves.

Antioxidant value of the varieties

An important step in maximizing the potential commercial success of the Three Sisters is a good knowledge of the composition of the foods produced, so that their nutritional potential can be evaluated. To identify the best varieties for food processing, another team evaluated the composition of the flesh of different squash varieties and the seeds of different bean varieties in order to determine their antioxidant value, which is a property that reduces oxidation in the human body and promotes health.

"My analyses revealed that Crookneck squash contains three times more total carotenoids than Algonquin pumpkin does. Those two squash varieties also differ in the types of carotenoids that they contain. As well, I studied the contents of anthocyanins and flavonols (two antioxidants) in four bean varieties: Hopi Black, Amish Nuttle, Early Mohawk and Gaga Hut Pinto. Hopi Black stands out from the other varieties, given that it contains nearly six times more anthocyanins."

- Marie Thérèse Charles, research scientist in postharvest physiology, Agriculture and Agri-Food Canada

Adding flour made from Crookneck squash or Hopi Black beans to a bread recipe could therefore increase the antioxidant content of the bread.

Breads made from Three Sisters flours

At AAFC’s Saint-Hyacinthe Research and Development Centre, research scientists tested Three Sisters varieties to identify which ones would work best for processing into food products.

In order for Indigenous niche breads to have qualities that are valuable to the companies that make the breads as well as to consumers, the loaves should be similar in volume and texture to the wheat breads that are available on the market. Indigenous niche breads could also be appealing by offering added value, such as a higher protein content, in comparison with conventional wheat breads.

To that end, a team produced flours from Three Sisters varieties, tested various bread formulations, including ones containing 10% of a Three Sisters flour, and then compared the loaves after they came out of the oven. The team found that several of the flours affected bread structure, preventing the loaves from rising as high.

"My analyses showed that, among the seven bean flours that we tested, four resulted in bread with better volume and texture: Mother Earth, Pole, Mr Rice and Red. In addition, the two blue corn flours and the Calico corn flour also have great potential for bread making."

– Sébastien Villeneuve, research scientist in food process engineering and Three Sisters project leader, Agriculture and Agri-Food Canada

The bean flours and corn flours were also analyzed to determine their protein content. Of the tested bean flours, four had higher protein contents: Black Eyed (the highest in protein), Mr Rice, Red and Macuzalito. The three corn flours contained less protein than the bean flours did.

The team also demonstrated that breads could be made with flours from peeled Crookneck squash or Algonquin pumpkin. However, the resulting loaves were lower in volume than breads made with bean or corn flour were.

Corn for soup or boiled bread

Among Indigenous communities, the nixtamalization of corn is an ancient culinary tradition. This process, which consists of soaking and cooking corn kernels in an alkaline solution made with wood ash, removes the outer hull of the kernels, improving their nutritional value and making them easier to use as an ingredient in foods. Nixtamalized corn kernels can be used to prepare a traditional soup or dried and ground into flour for making boiled bread.

Nixtamalization offers the potential to create other niche food products. A team compared the corn varieties White, Red Mohawk, Blue and Calico to determine which ones are best suited to nixtamalization.

"Using a lime-based process that imitates the traditional wood-ash method, I tested the ability of the corn kernels to absorb water, a property that makes them easier to cook. In the end, the best variety for nixtamalization is White corn, which is precisely the variety traditionally used by Indigenous peoples."

– Martin Mondor, research scientist in membrane technologies, Agriculture and Agri-Food Canada

An ancestral agricultural tradition with promise for the future

Thanks to the informed data gathered on ancestral varieties of corn, squash and beans that have potential as ingredients in niche foods, interested Indigenous communities would be able to assess the feasibility of modernizing and optimizing the value of their ancestral agricultural tradition. On their own land, Indigenous communities will be able to produce the Three Sisters crops on a larger scale in a manner that respects community values and traditions. Local, community or private companies could be established, creating economic, social and cultural wealth in their communities.

Although other avenues will be worthwhile topics for joint research, the first seeds have already been planted to ensure that Canada can preserve and optimize the value of this component of the culture and ancient know-how of First Nations.

Key discoveries (benefits)

  • Crookneck squash and Hopi Black beans were found to contain higher levels of antioxidants, including carotenoids, anthocyanins and flavonols.
  • Facts on flours made from the Three Sisters and used in food processing:
    • Bread made with 10% Mother Earth, Pole, Mr Rice or Red bean flour offered the best volume and texture.
    • Blue corn flour and Calico corn flour work well for bread making.
    • Four of the Three Sisters flours—Black Eyed (the highest in protein), Mr Rice, Red and Macuzalito bean flours—had higher protein content than the other flours did.
  • White corn is the corn variety best suited to the nixtamalization process, an ancient Indigenous culinary tradition that increases the nutritional value of corn kernels and makes them easier to use.

Photo gallery

Sébastien Villeneuve, research scientist in food process engineering and Three Sisters project leader.
Marie Thérèse Charles and Dominique Roussel (research assistant) working to extract anthocyanins from bean seeds.
The Three Sisters (squash, corn and beans) growing side by side.
Martin Mondor and Hélène Drolet (research assistant) working on the nixtamalization of Blue corn.

Loaves of bread made with 10% bean flour. The green squares indicate the loaves with the best texture in comparison with the wheat flour bread on the left.

Related information