Potato seed selection is the first and most critical step for successful cultivation. In agriculture, seed potatoes are actually tubers—parts of the potato plant’s stem. A high yield is achieved only when the seed comes from parent plants that have the highest productivity. This phenomenon happens because the new crop inherits both the traits and the weaknesses of the parent potato. When the mother plant belongs to a tasty and productive variety, its offspring will also be of outstanding quality.
Potato seed selection largely determines the future yield, as it affects plant resistance, tuber quality, and storage life.
Potato seed selection: What is the process?
Many potato growers produce and select their seeds from their fields. The important thing is that they do this during the potato growth phase and not after harvest. Therefore, they visit their fields 25-30 days after germination begins. They point out the strongest potato plants, which have 3-6 vigorous shoots, and place a reed next to each as a marker. A month later, they revisit these marked potato plants. If they are still vigorous, with many leaves and shoots, and not sparse, then leave the marker in place. At this stage, the leaves should not exhibit wrinkles, curls, or any signs of disease.
During the harvesting season, they first carefully harvest the potatoes from these marked plants without damaging the plants. They sort them by size and use only the best and medium-sized ones for planting the following season. If the field has weak plants with shriveled leaves or plants affected by rot, growers should replace the seed and obtain healthy plants from another source to prevent further damage to their crop.
If the field contains weak or diseased plants, growers should replace their potato seed stock with healthy ones from another source to avoid spreading infection.
Potato seed selection: Which potatoes should we plant?
In Greece, the best varieties for spring planting are potatoes from cold and mountainous regions. These regions typically harvest potatoes late, after August or September. Because of the winter, they ripen very well until spring and are richer in starch.
Farmers should make seed purchases as early as possible. The process allows producers to store them properly until the planting season. We plant healthy, firm potatoes with no internal voids, rather than soft, heavy, and shallow-eyed potatoes. They should also not have black or dark spots on their skin or flesh. Avoid bruised, damaged, or insect-pierced potatoes—and always make sure they are fully mature.
To ensure proper growth and high yields after your potato seed selection, you can also check our potato nutrition program with detailed guidelines for fertilization stages and plant nutrient requirements.
When are potatoes mature enough to harvest?
A mature potato does not peel easily when rubbed between the hands. Harvesting immature potatoes may yield early, but the volume will be smaller. Full maturity occurs when the crop remains in the soil 5–8 days after the leaves and stems have completely dried out.
How potato seed selection and tuber size affect yield
Experiments have shown that planting large, healthy seed tubers results in higher yields. Such potatoes contain more starch, and the plants are more resistant to pests and diseases. This phenomenon is because the mother potato provides more nutrients to the new plant, producing more vigorous shoots and leaves and, consequently, better-fed tubers.
However, using only enormous seed potatoes would require large quantities of seed material. Medium-sized potatoes—about the size of a hen’s egg, with firm and floury flesh (19–20% starch)—are the most efficient choice. Massive ones do not significantly increase yield compared to medium ones.
Planting two or three smaller tubers yields less than planting one large, healthy seed potato. If the seed tuber comes from a diseased or degenerated plant, the harvest will remain poor, even if large tubers are used.
Correct potato seed selection, combined with appropriate tuber size, ensures consistent, high-quality production every growing season.
Did you know that….
When the soil is poor and moist, and the weather is unfavorable, potatoes larger than a hen’s egg should be used for planting.
Research also demonstrates that a seed with three to four vibrant eyes yields a more successful harvest.
Conclusion
In summary, potato seed selection remains a key factor in the crop’s success, regardless of variety or climate.
Some growers, when planting whole potatoes, tend to cut off extra eyes with a knife, leaving only one strong eye at the top. However, this cutting process is labor-intensive and costly. In practice, growers usually use potatoes with 5–6 eyes or only the upper part of the tuber. Potatoes with too many eyes produce numerous but weak shoots, resulting in smaller tubers.