How to Save Lettuce Seeds? A Detailed Guide to Scientific Seed-Saving Measures

Celtuce, also known as stem lettuce, is a variant of the lettuce species in the Asteraceae family, Lactuca genus, that can form a fleshy tender stem; it is an annual or biennial herbaceous plant. It is also called stem lettuce, asparagus lettuce, green lettuce, and lettuce vegetable. Harvest period: January to April. It originated in Central or North China. The aboveground stem is edible; the stem skin is white-green, the stem is crisp and tender, the young stem is emerald green, and it turns white-green after maturity. The main edible part is the fleshy tender stem, which can be eaten raw, in cold dishes, stir-fried, dried, or pickled; the tender leaves are also edible. The stem and leaves contain lactucin, which is contained in the stem and leaves. It tastes bitter and has an analgesic effect. Celtuce has strong adaptability and can be cultivated in spring and autumn or overwintered, mainly in spring cultivation, and harvested in summer.

The medicinal value of celtuce

1. Promoting digestion and relieving stagnation: Lettuce has a fresh taste with a slight bitterness, which can stimulate the secretion of digestive enzymes and increase appetite. Its milky sap can enhance the secretion of gastric juice, digestive glands, and bile, thereby promoting the function of various digestive organs, and is especially beneficial for patients with weakened digestive function, reduced acidity in the digestive tract, and constipation;

2. Diuresis and promoting lactation: The potassium content of lettuce is much higher than its sodium content, which helps maintain the body's water and electrolyte balance and promotes urination and milk secretion. It has a certain dietary therapeutic effect on hypertension, edema, and heart disease patients;

3. Strengthening the body and preventing and fighting cancer: Lettuce contains a variety of vitamins and minerals and has the effect of regulating nervous system function. Among its organic compounds, it is rich in iron that the human body can absorb, which is very beneficial for patients with iron deficiency anemia. The hot water extract of lettuce has a high inhibition rate on certain cancer cells, so it can also be used to prevent and fight cancer;

4. Loosening the intestines and relieving constipation: Lettuce contains a large amount of plant fiber, which can promote intestinal wall peristalsis, clear the digestive tract, and help with defecation, and can be used to treat various types of constipation;

5. Celtuce has a relatively high potassium content, which helps promote urination, reduces pressure on the atria, and is extremely beneficial for patients with hypertension and heart disease. It contains a small amount of iodine, which has a major impact on human basal metabolism, mental and physical development, and even emotional regulation. Therefore, celtuce has a sedative effect, and regular consumption helps eliminate tension and aids sleep. Unlike ordinary vegetables, it contains very rich fluorine, which can participate in the growth of teeth and bones. It can improve the function of the digestive system and liver. It stimulates the secretion of digestive juices, promotes appetite, and helps resist rheumatic diseases and gout.

Scientific seed-saving measures for celtuce

Celtuce is a high-temperature-sensitive crop, and the vernalization stage generally does not require low temperature. In stage development, it does not have strict requirements for long-day conditions; it can flower not only in spring and summer but also when cultivated in autumn, so it is relatively suitable for saving seed by oneself. Therefore, vegetable growers mostly save seed themselves. However, the seed saved must be an excellent conventional variety, and attention must be paid to the seed-saving method.

1. Selection of the seed-saving site. Farmers often select excellent individual plants from commercial celtuce for seed saving, but attention must be paid to the seed-saving conditions. After celtuce plants bolt, flower, and set seed, they are susceptible to lodging and reduced yield due to strong winds and rain, so the seed-saving site should, as far as possible, be chosen in a wind-sheltered place with good drainage and irrigation conditions and not too fertile soil. Although celtuce is a self-pollinating crop, its outcrossing rate is about 1%, so attention must be paid to isolation from other varieties; both natural distance isolation and time isolation can be used. A natural isolation distance of 100-300 m is preferable, and time isolation means staggering the flowering period by more than 30 days.

2. Selection of excellent individual plants. When spring fleshy celtuce that has overwintered reaches the commercial harvest standard, conduct field selection. Select plants with the typical characteristics of the variety, late bolting, tight internodes, no side branches, few leaves, thick stems that do not split, and no pests or diseases as seed plants. Harvest the unselected plants for market. Mark the seed plants and number them separately.

3. Strengthening field cultivation and management. Remove the lower leaves and withered, rotten leaves from the selected seed plants, and earth up around them. Open the surrounding ditch and furrow ditch well, and frequently clear the drainage ditch to prevent blockage and avoid waterlogging in the field. In order to prevent lodging caused by windy and rainy days, it is best to insert supports. In the later stage, celtuce is prone to downy mildew, aphids, and other pests and diseases, so prevention and control work must be done effectively. To control downy mildew, spray with 25% metalaxyl at 400-500 times dilution, starting at the early stage of disease onset, once every 7-10 days, for a total of 2-3 sprays; to control aphids, use 10% imidacloprid (also known as imidacloprid, Dagongchen, Kangfuduo, Yibianjing) at 2500-3000 times dilution.

4. Timely harvesting. Around June, when the corolla turns yellow and then brown, and white hairs protrude from the inflorescence, the seeds are basically mature and must be harvested promptly; otherwise, the white pappus on the seeds is easily blown away by the wind, carrying the seeds away, or the seeds rot and fall off when it rains. In view of the relatively large difference in maturity among inflorescences on different parts of the celtuce plant, harvest in stages, or harvest the whole plant after most inflorescences have matured, then dry it.