The key of crop measures in this period is to mobilize the nutrients, water and endogenous hormones of seed potatoes to promote early germination, more roots, faster germination and Miao Zhuang.
(2) At the seedling stage, it was unearthed from the seedlings and experienced the development of roots and the seedling stage of the main stem. Because seed potato is rich in nutrition and water, a considerable number of roots and embryonic leaves are formed before emergence.
After emergence, the root system continued to expand and the stems and leaves grew rapidly. Most varieties elongate the stolon at 7- 10 days after emergence, and the top begins to swell at 5- 10 days. At the same time, the first inflorescence at the top began to sprout and side branches began to appear. The growth center of this period is the growth of stems, leaves and tubers.
(3) In the tuber formation stage, the first inflorescence begins to blossom after the rudiment of tuber is unfolded by the capped leaves at the top of aboveground stem, and the top of stolon of the whole plant begins to swell until the maximum tuber diameter reaches 3-4 cm, and the dry weight of stem and leaf in the upper part of underground reaches a balance with the dry weight of tuber.
This period is the key to determine the number of potatoes per plant, which usually lasts about 30 days. Agricultural measures promote the growth of stems and leaves with water and fertilizer, and quickly establish an assimilation system. At the same time, intertillage combined with soil cultivation created conditions for stem expansion.
(4) The tuber growth period starts from the dry matter balance between the aboveground part and the underground part, that is, it enters the tuber growth period, at which the leaf area has reached the maximum, and the growth of stems and leaves gradually slows down and stops; Nutrients produced by aboveground parts are transported to tubers, and the volume and weight of tubers are increasing, which is the key period to determine the volume of tubers.
(5) Starch accumulation period, from the beginning of stem and leaf aging, to the tuber volume and weight continue to increase. The growth characteristic of this period is that the aboveground parts transport carbohydrates, protein and ash to tubers, and the weight of tubers is the largest day by day.
The accumulation of starch continued until all the stems and leaves died. The main measure of crops is to keep the roots, stems and leaves growing slowly during the day and accelerate the transfer of assimilates to tubers. The harvest time depends on the production purpose and the requirements of crop rotation. The mature harvest period is generally when the shoots and leaves of plants turn yellow and wither, and the starch in the stems accumulates sufficiently.
Extended data:
environmental conditions
1, temperature: potato tubers can germinate above 4℃ and freeze below 0℃. The optimum storage temperature of potato tuber is 0℃-4℃. Potatoes like cold climate, and the optimum germination temperature of buds on tubers is 12℃- 16℃, which germinates rapidly at 18℃-25℃, but the seedlings are weak.
The suitable soil temperature for tuber development is 16℃- 18℃, preferably no more than 2 1℃. When the temperature is higher than 25℃, it is not conducive to tuber expansion. High temperature will prevent tubers from growing.
2. Moisture: Water is most needed during tuber formation. The soil water content should be 70-80% of the maximum field water capacity in the early stage and peak stage of tuber formation, and 60% of the maximum field water capacity in the late stage of tuber formation.
Therefore, early-maturing varieties grow rapidly from bud stage to the end of flowering, forming a large number of tubers and requiring the most water. The whole process from flowering to stem and leaf stop growth of middle-maturing varieties belongs to tuber expansion period, which is longer than that of early-maturing varieties.
3. Light: Potato is a light-proof crop. Insufficient light intensity or too dense planting during the growth period will make the stems and leaves grow white, delay tuber formation and reduce disease resistance. The length of sunshine directly affects plant growth and tuber formation. Long sunshine can promote the growth and germination of stems and leaves, while short sunshine is beneficial to tuber formation. Under the sunshine of one day 1 1- 13 hours, stems and leaves are developed, photosynthesis is vigorous, and tuber yield is high.
4. Soil: Potatoes are most suitable for soils with deep plough layer, loose structure, good drainage and air permeability and rich organic matter, such as paddy soil (loam) and sandy loam in Pingchuan, Hanzhong. Soil viscosity affects root development and tuber expansion, making tuber deformed, bud eye protruding and potato skin rough. Potatoes are suitable for growing in slightly acidic soil, and potatoes are easy to scab in alkaline soil.
References:
Baidu encyclopedia-potato cultivation