Method of planting lettuce: planting method, time and soil conditions of lettuce

The method of lettuce planting is introduced in three aspects, the importance of lettuce seed characteristics, suitable temperature and soil conditions.

Planting time: lettuce in the Yangtze River Basin overwinters in the open field, mainly spring lettuce, usually sown in September-October of the next year.

Seed characteristics: lettuce seed germination temperature is 15-20. C, germinate poorly in high temperature environment, easy to enter dormancy, 30. Germination is hindered above C.

Seed soaking will break dormancy under low temperature environment. Seeds are immersed in running water for 10-12 hours at low temperatures of 4-6. C, about 3 to 5 days will break the dormancy. Seeds can still germinate in high temperature environment after breaking dormancy, but if only soaking seeds without breaking dormancy at low temperature, they will also enter dormancy. Fresh seeds are more sensitive to high temperature than mature seeds. The seeds that break dormancy should be dried and sown before the radicle breaks through the seed coat. Do not rub the seeds that break dormancy with gravity, otherwise the endosperm and roots will lose their germination ability due to mechanical damage.

Growth temperature: lettuce is a temperature-sensitive vegetable, in the appropriate seedling age can be induced by high temperature induction flower bud differentiation, warm long days to promote flowering. The optimum temperature for growth is 12-20 ℃. C，24。C is growing vigorously, 24. C above easy to small plant sprout. The number of cultivars is 21. C is higher than that, the leaf bulb is not easy to form, the temperature is too high, it is easy to cause the necrosis and decay of the heart leaf tissue.

The leaf lettuce is a cool type crop. Autumn and winter and spring are suitable cultivation periods in Taiwan. The leaf lettuce of both local varieties can be cultivated all year round, but it is easy to sprout in high temperature period. Bulb and tender stem varieties were not suitable for cultivation at high temperature stage, leaf bulb of bulb-bearing varieties was not easy to form at high temperature stage, and stem of tender stem varieties was not easy to grow fat. Standing leaf and wrinkled leaf varieties are easy to sprout at high temperature, and bitter thick.

Soil conditions: lettuce although wide adaptability to the soil, but because of its small root group, only distributed in the topsoil, so good drainage, fertile organic sandy loam best, pay attention to keep the soil moist during growth. pH 5.5-6.5 is appropriate.