Keep the spring rod in time. After the spring, asparagus began to sprout tender stems, and at this time cocoa harvested tender stems and became green asparagus. After harvesting for a period of time, keep the spring mother stem. Generally speaking, 2-3-year-old asparagus will be preserved until mid-April, and asparagus above April will be preserved from late April to early May.

The specific time to leave stems is to dig stems and buds neatly in the whole bamboo shoot field, and choose sunny days. The number of female stems depends on the years of asparagus planting and the size of the tree tray. 3-4 stems are preserved for two years, 4-5 for three years, and 6- 10 for more than four years. The female stems should be solid stems, with a stem diameter of 1- 1.5 cm, which are evenly distributed and not closely connected.

Extended data:

Asparagus has a strong adaptability to temperature, which is both cold and heat resistant. It can be cultivated from sub-cold zone to subtropical zone, but it is most suitable for temperate zone with distinct seasons and pleasant climate.

The initial germination temperature of asparagus seeds is 5℃, and the optimum temperature is 25 ~ 30℃. When the temperature is higher than 30℃, the germination rate and germination potential decrease obviously. Breeding with seeds can continue to grow for more than 10 years.

In winter, the aboveground parts wither, and the rhizomes and fleshy roots hibernate. In warm areas in winter, the dormancy period is not obvious, and the dormancy period is extremely resistant to low temperature. When the ground temperature rises above 5℃ in spring, scale insect buds begin to germinate. The tender stems began to elongate above 65438 00℃. 15 ~ 17℃ is the most suitable for bud formation;

Above 25℃, the buds are thin, the scales are scattered and the tissues are aging. At 30℃, the bud elongation is the fastest, and at 35 ~ 37℃, the plant growth is inhibited and even withered into summer sleep. The suitable temperature for photosynthesis of asparagus is 15 ~ 20℃. When the temperature is too high, the photosynthetic intensity is greatly weakened, the respiration is enhanced and the photosynthetic productivity is reduced. Asparagus grows 2-3 times or more new stems every year.

Generally, the tender stems germinated in spring are used for food, and their growth depends on the nutrient supply stored in the roots of the previous year. The growth and yield of tender stems are positively correlated with the number of mature stems and the lush degree of branches and leaves in the previous year. With the growth of plant age, the number and yield of tender stems increased year by year. With the continuous branching of rhizomes, the development of plant clusters tends to decline, the aboveground stems become smaller and smaller, and the yield and quality of tender stems gradually decline. Generally, 4 ~ 10 years after colonization is the reproductive period.

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