How should seed potatoes be treated to achieve high yields?

Treating seed potatoes before sowing not only helps potato seedlings grow strong and emerge early, but also effectively prevents seed-borne and soil-borne diseases, making it one of the important steps for achieving high-quality, high-yield potatoes. So how should seed potatoes be treated for high yields?

1. Sunning the seed potatoes

Potatoes generally require 125-150 kg of seed potatoes per mu. Sunning the seed potatoes before sowing can help break dormancy and promote uniform sprouting. Choose a sunny day, place the selected seed potatoes in sunlight at a temperature of 12-15°C, and sun them for 2-3 days; then they can be cut into pieces and sprouted according to tuber size. During sunning, turn them once a day so the seed potatoes are evenly exposed to light, and while turning, remove rotten tubers, soft black-rotted diseased tubers, deformed tubers, and frost-damaged tubers.

2. Cutting seed potatoes into pieces and sprouting

Sprouting before sowing can promote early emergence of potatoes, advancing the potato growing period by 7-10 days. It is an important measure for bringing spring potatoes to market earlier, and it also helps avoid the damage from high temperatures and aphids later on. It is a key technique in spring potato production. Sprouting is generally carried out about 25 days before the local suitable sowing period for potatoes.

(1) Timing of cutting into pieces

It is best to do this 1-2 days before sprouting. If cutting is done too early, it is easy to cause excessive water loss from the tuber pieces or lead to seed piece rot.

(2) Disinfecting the knife

To prevent artificial spread of disease, prepare two knives when cutting and disinfect them before cutting by dipping them in 75% alcohol or 0.5% potassium permanganate solution. Use them alternately. Especially when cutting diseased or rotten tubers, stop immediately, dip the knife into the prepared disinfectant solution, then switch to the other knife before continuing, to prevent spreading disease during cutting.

(3) Cutting method

Because the tail bud of the potato sprouts slowly and the yield of the mature plant is very low, only one third of that from the top bud, the tail bud should be removed when cutting the potato into pieces. The cut pieces should be uniform in size, generally 25-30 grams each, and each piece should retain at least one healthy bud eye. After cutting, spread the seed pieces in a sheltered, sunny place to dry, so the wounds heal.

(4) Seed dressing

To prevent the cut surfaces of the tuber pieces from being infected by pathogens and at the same time prevent seedling-stage diseases, it is best to use a high-quality, appropriate seed coating agent for seed dressing. Mix 100 ml of Liangdun or 100 ml of Shileshi or 50 ml of Maishuping with 1.5 L of water, spray it onto 150 kg of seed potatoes, and then mix well. This can prevent seedling-stage diseases such as black scurf, and can also make the tuber pieces sprout early and grow strong sprouts.

(5) Sprouting

After the dressed seed pieces are put into baskets and dried, they can be sprouted using a plastic tunnel or a heated sunken bed. During sprouting, spread one layer of tuber pieces and then scatter one layer of wet sand; 3-5 layers of tuber pieces can be laid continuously, and finally cover the top with straw mats or felt cloth to retain moisture. During sprouting, maintain the temperature at 18-22°C. When the sprouts grow to about 1-2 cm, place them under diffused light to air and dry so they are evenly exposed to light. Once the sprouts turn green, they are ready for sowing.

3. Spraying the furrow with pesticide

At sowing, after opening the furrow and placing the seed potatoes, spray the furrow with 100 ml of Amistar per mu mixed with 15-30 kg of water, and cover with soil after it dries slightly. This can better prevent diseases such as black scurf and powdery scab, and can improve tuber quality.