What are the characteristics of potato in different growth stages?

The growth and development of potato takes five stages as a cycle: dormancy stage, germination stage, seedling stage, tree-growing stage and potato-bearing stage. In each growth stage, it has its own different development characteristics. Then, according to this cycle order, it will talk about the characteristics of each growth and development stage in turn.

First, the developmental characteristics of dormancy

After the potato tuber is ripe and harvested, it will not germinate even if it is given suitable conditions. This phenomenon is called potato dormancy, and this period is also called dormancy. This is a kind of self-protection for bad environment formed by potato in the process of evolution.

The dormancy characteristics of potato tubers are closely related to production and consumption. The length of dormancy period has an influence on the storage tolerance of tubers, whether they can emerge after sowing and the yield, which is often the main influencing factor for high yield.

the length of dormancy period varies with varieties and storage conditions. At about 26℃, the dormancy period varies from one and a half months to three months. Tubers can be dormant for a long time at ~4℃, and the dormancy period will be shortened with the gradual increase of temperature. The dormancy period of large warp of the same variety is shorter than that of small tuber, while the dormancy period of terminal bud on the same tuber is shorter than that of base.

the way to break the dormancy of potato tubers is to choose a place favorable for germination to accelerate germination. Cut the seed potato into pieces, keep 1~2 buds in each piece, and put it in a cool and ventilated place. One layer of potato pieces and one layer of wet sand are piled up layer by layer to keep it moist, and it can germinate after 7~1 days. Pharmaceutical treatment. At present, gibberellin is widely used. The cut tuber is soaked in .5~1 ml/L gibberellin solution for 5~1 minutes, taken out, dried, layered and germinated before sowing. You can also soak potato pieces in .5%~1% thiourea solution for 4 hours, take them out, put them in a closed container for 12 hours, and then bury them in wet river sand. Most of them can germinate after about 1 days.

second, the developmental characteristics of germination stage

from tuber bud germination to bud germination stage. After the tuber buds germinate, they begin to elongate and grow, and finally form obvious buds. When the bud was unearthed, the leaf primordium on the main stem had been differentiated, and the terminal bud became a flower bud, showing a spherical shape. At this time, the buds in the growth center elongate, root and form stolons. The main factor affecting the growth of buds and roots is temperature. When the temperature is not lower than 4℃, the dormant tuber begins to germinate, but does not elongate. The buds began to germinate at 5℃~7℃, but it was very slow. When the temperature is 1℃~12℃, the buds grow healthily and rapidly, and 18℃ is the best. When the temperature exceeds 36℃, the buds are not easy to germinate and a large number of rotten seeds are easy to form.

In short, the buds and roots grow weakly when the temperature is too high, and germinate slowly when the temperature is too low. Spring sowing in production begins when the ground temperature of the tillage layer (~1 cm) is stable at 7~8℃. High temperature is the main factor affecting the emergence of robust buds when sowing in autumn. In the northern planting areas, there is heavy wind and sand, little rain and slow temperature rise in spring, mainly to improve the ground temperature, and adopt early sowing, loosening soil, promoting early germination, early emergence and strong seedlings; In the southern planting areas, it is mainly to reduce the ground temperature, keep the suitable soil moisture, and promote the rapid emergence, full seedling and strong seedling.

third, the development characteristics of the seedling stage

The seedling stage is from emergence to the sixth or eighth leaf spreading, which is equivalent to the growth of a leaf sequence, so it is also called a cluster tree, which is the growth of the second stage of potato. At the seedling stage, the root system continued to grow and develop, and the stem and leaf growth was not large, but the leaf spreading speed was very fast, and one leaf occurred in about 2 days. In the second growth stage, the stem and leaf of the third stage have been differentiated.

No matter whether planted in spring or autumn, the seedling period is only half a month, so we should strengthen field management, topdressing early to promote the rapid growth of seedlings, and strengthen tillage and weeding to keep moisture and ventilation.

4. Developmental characteristics of the flowering period

It usually takes about one month from the clumping of trees to the flattening of 12-16 leaves, when the first inflorescence of early-maturing varieties blooms and the second inflorescence of late-maturing varieties blooms.

The developmental characteristic of this stage is that the stem begins to rise sharply, accounting for about 5% of the total height; The main stems and stems and leaves are all built, and some branches and leaves are expanded. At the same time, the root system continues to expand, and the tuber gradually expands, and the dry weight of the tuber has exceeded 5% of the total dry weight of the plant, indicating that the growth at this time has changed from vegetative growth to reproductive growth.

v. development characteristics of tuber-bearing stage

after the completion of the tree-bearing stage, it enters the tuber-bearing stage with tuber growth as the main factor. The development characteristics of this period are that the development of stems and leaves is decreasing day by day, the basal leaves begin to turn yellow and fall off, and the organic materials in various parts of the plant are transported to the tuber, and the tuber expands rapidly. Especially in the 1th day of flowering, the expansion rate is the fastest, and about half of the yield is formed in this period.

The tuber setting period is generally 3-5 days, and the cultivation should focus on protecting seedlings and attacking tubers, with sufficient fertilizer and water, suitable temperature difference between day and night and strong illumination, so as to keep the stems and leaves from decaying, promote nutrient production and transport nutrients to tubers, and obtain high yield and high quality tubers.

The most suitable ground temperature for tuber formation is 16℃~18℃, and the tuber grows slowly at 25℃. At 3℃, the tuber stops growing because the respiration consumption exceeds the nutrient accumulation. At this time, all the nutrients transported from the leaves are used for the growth of buds on the tuber. When the local temperature decreases due to rainfall or watering, the growing buds on the tuber stop growing and accumulate nutrients again, thus forming seed potatoes and abnormal potatoes.

The above are the growth and development characteristics of potatoes in different periods. By understanding these development characteristics in different periods and applying them flexibly in actual planting, it is of practical significance to obtain high yield and high quality.