What is a landrace?
A landrace is a traditional variety of a crop which has more genetic diversity than our modern cultivars. What does that mean? Well, each plant has genes that determine things such as the colour, size, and water and nutrient needs of the crop. Modern cultivars usually have one type of each gene, which means if you take the seeds from that cultivar and plant them, you will end up with the exact same plant you planted last year. A landrace has multiple types of each gene, so any seeds grown from the plant may have different characteristics from last year's plant and each other [1]. This can have many benefits, which are discussed below.
Benefits of planting landraces
Here are some benefits of planting landraces:
- Better able to adapt to extreme conditions. Because landraces have so many types of genes, some of the plants grown will have genes that help them survive better in higher or lower temperatures, water levels, and nutrient levels. Some genes may also protect a plant from pests. Planting a landrace in an extreme environment and collecting the seeds for several years will eventually lead to it adapting to the climate, which means you might get better results than growing something from the garden centre. It also means that your crop will be better protected from the effects of climate change. [1]
- Uses less water, fertilizer, and pesticides. The ability of landraces to adapt to their environment means that they may need less watering and chemicals to grow successfully. This saves time and money, preserves water, and prevents potentially harmful chemicals from polluting the environment. [1]
- Conservation of genes. Just like how plants and animals can go extinct, certain genes in a plant can go extinct as a result of modern breeding techniques. As stated above, these genes can be important because they can make the plant better suited to different conditions. Landraces contain many genes that may have been bred out of modern cultivars, so growing them helps to preserve these genes. These landraces can then be bred with the modern cultivars to potentially make new, better adapted cultivars. [1]
How to plant a landrace
There are two methods you can use to grow a landrace: planting an existing one, or creating your own. It's also important to keep in mind before starting that you will need to grow a fair amount of plants at one time to maintain the landrace over several years, so be sure to set aside a large space in your garden to do this. If you don't have much space, you can still try, but you may find your plants become more and more similar as certain genes will accidently be bred out. [2]
Method 1: Plant an existing landrace
Planting a existing landrace is a simple way to enjoy the benefits of landraces while also preserving a traditional variety of a crop. You can find seeds for various landraces for sale online. For best results, choose a landrace from an area with similar conditions to yours (while most landraces will eventually adapt to your conditions, you may have several years of lower yields before this happens).
Method 2: Create your own landrace
You can also create a landrace of your own. While it will not have the same history and diversity as a "true" landrace, it will still be more adaptable than any modern cultivar on its own.
To create a landrace, start by choosing a crop. The easiest crops to use are ones you can harvest while also allowing the plant to produce seeds. Crops such as tomatoes, peppers, or lettuce are good options, which radishes and carrots are not. Once chosen, collect seeds for several different cultivars. The more different the cultivars, the more types of genes will be in your landrace. Just be sure to check that the scientific names on the packages all match (this can be a problem for some crops such as hot peppers which come from several species). Then plant them side by side following the package directions. After several years of collecting seeds and planting them using the method descibed below, you will have a unique, genetically diverse variety of your own. [2]
Maintaining your landrace
While a variety of genes can help your landrace to adapt and survive, too much variety can cause problems, including poor quality fruit and, ironically, an inability to survive your local conditions. Fortunately, with proper maintainance you can prevent these genes from from becoming an issue.
Let's start with addressing the inability to survive local conditions. You might be thinking you need to protect your plants from harsh conditions, right? While that is good for cultivars, which can't adapt, your landrace can do that. So in order to maintain this characteristic, you need to let it suffer a bit. Don't apply chemical fertilizer, water it only occassionally, and apply natural pesticides only in extreme circumstances. This will cause some plants to die, especially in your first year of creating a landrace, but it will help to remove genes that make your landrace incompatible with your environment. [2]
The other consequence of too many types of genes is a poor quality harvest. This might mean fruits or vegetables that are bitter, have a bad texture, don't ripen, or are simply tasteless. This is prevented by only collecting seeds from the plants with the desired qualities. To do this, it's important to first decide which qualities are the most important to you. This will almost always be the taste and texture of your crop, as well as ripening time if you find your plants don't ripen before frost. Other qualities like size, shape, and amount of fruit may seem important, but by regulating those, you lose genes that could be useful for other things like adapting to the environment. Collect many seeds from a variety of plants that show the qualities you want, save them as usual, and plant these seeds next year to continue your landrace. [2]
References
1. Villa, T. C., Maxted, N., Scholten, M., & Ford-Lloyd, B. (2005). Defining and identifying crop landraces. Plant Genetic Resources, 3(3), 373-384. https://doi.org/10.1079/pgr200591
2. Lofthouse, J. (2021). Landrace gardening: Food security through biodiversity and promiscuous pollination.