Effects of Potassium De ciency on Growth of Pakchoi in Cold and Dry Areas


 [Background] To reveal the effect of potassium deficiency on the growth and development of pakchoi in cold and dry areas.[Results] The effect of potassium deficiency on the growth status of P. pakchoi in cold and dry areas was significant. P. pakchoi treated with potassium-free nutrient solution had the best growth, the largest number of leaves, leaf length, leaf width, leaf area, root length and weight; P. pakchoi treated with 100% potassium deficiency had the smallest plant, leaf length, leaf width, leaf area, root length and weight; P. pakchoi treated with potassium deficiency 50% had the middle growth and development status, and the root ratio was the smallest in d 21.[Conclusion] Potassium can effectively promote the growth and development of pakchoi in cold and dry areas, increase its root length, leaf width, leaf area, weight, etc. The quality of the upper part and the underground part of d,21 of pakchoi treated with deficiency is the most different.


Abstract
To reveal the effect of potassium de ciency on the growth and development of pakchoi in cold and dry areas.
[Results] The effect of potassium de ciency on the growth status of P. pakchoi in cold and dry areas was signi cant. P. pakchoi treated with potassium-free nutrient solution had the best growth, the largest number of leaves, leaf length, leaf width, leaf area, root length and weight; P. pakchoi treated with 100% potassium de ciency had the smallest plant, leaf length, leaf width, leaf area, root length and weight; P. pakchoi treated with potassium de ciency 50% had the middle growth and development status, and the root ratio was the smallest in d 21.
[Conclusion] Potassium can effectively promote the growth and development of pakchoi in cold and dry areas, increase its root length, leaf width, leaf area, weight, etc. The quality of the upper part and the underground part of d,21 of pakchoi treated with de ciency is the most different.

Background
Inner Mongolia is a middle temperate monsoon climate area with less and uneven precipitation, shortage of water resources and low temperature in the whole year, which makes crop growth need certain environmental conditions. This experiment shows the effect of potassium de ciency on the growth and development of pakchoi in cold and dry areas. To guide the cultivation and growth model of pakchoi in Inner Mongolia combined with fertilization management to improve the yield of pakchoi [1][2][3] With the improvement of people's living standard, people pay more attention to the pursuit of health.As a kind of green organic vegetable, pakchoi is rich in many nutrients needed by human body, and gradually becomes an important choice for people to eat. Potassium is one of the three elements of fertilizer, which is involved in almost all biochemical processes in plant growth and development. It is called quality element and stress resistance element [4] The results showed that the leaf senescence of pakchoi was accelerated under the condition of potassium de ciency. The results showed that with the increase of potassium concentration in nutrient solution, the fresh quality, cell yield, leaf length, plant height, leaf number, dry quality and root dry quality of each plant increased to varying degrees. Soilless cultivation technique was applied in this study [5][6] The effects of potassium de ciency on leaf number, root length, leaf length, leaf width, underground fresh weight, aboveground fresh weight, underground dry weight, aboveground dry weight, aboveground dry weight, leaf area, root-crown ratio in cold and dry areas of Inner Mongolia were studied.

Test materials
In this study, pakchoi was used as experimental material, and the nutrient solution was green leafy vegetable nutrient solution [7] and set up no potassium de ciency (CK), potassium de ciency 50% and potassium de ciency 100%,3 treatments. The leaf length, leaf width and root length of pakchoi were measured directly by millimeter, and the leaf area of each pakchoi was calculated equal to the average leaf length x the average leaf width of the maximum leaf length, and the number of leaves was calculated. The fresh weight of the upper and underground parts of rapeseed was measured by 1/10000 days, then dried by dryer (78℃) to constant weight, and the dry weight of the above ground and underground parts was measured by 1/10000 days.
WPS o ce Excel,SPSS 18.0 is the data processing software used Fresh weight of root to crown ratio = ground/ground fresh weight (1) Water content /%=(fresh weight-dry weight)/ fresh weight ×100 (2) 2 Fruit And Analysis    The dry weight of the upper part of the cabbage was higher than that of the potassium de ciency 100% nutrient solution, 0.18,0.493,1.93,4,10.683 g,, respectively After treatment with potassium-free nutrient solution, the maximum dry weight of the upper part of the vegetable eld was 0.237,0.557,2.63,4.03 and 11.13 g, respectively It was signi cantly higher than the dry weight of the upper part of the vegetable eld treated with potassium de ciency 50% and potassium de ciency 100% nutrient solution, The results showed that potassium could promote the increase of dry weight in the upper part of cabbage, most obvious in d 35. Figure 8 shows that under the same nutrient solution treatment, the root and crown ratio of pakchoi did not change obviously with the prolongation of planting time, and the effect of potassium de ciency treatment on root and crown ratio of pakchoi was signi cant. The root-to-crown ratio of pakchoi increased rst and then decreased d 7,14,21,28 and 35 treated with potassium de ciency 50% and 100% nutrient solution, and reached the minimum value in d 21, indicating that the quality difference between the upper part and the underground part of pakchoi treated with d,21 was the greatest.
2.5 Effects of potassium de ciency on water content of cabbage Figure 9 shows that, Under different nutrient solutions, The water content of pakchoi was above 88% with the extension of planting time, At d 28, the water content reaches its maximum, No potassium de ciency, potassium de ciency 50%, potassium de ciency 100% nutrient solution irrigated. The water content of pakchoi was 96.3%,95%,96.8%, The water content of cabbage was higher d 7,14 and 21.The possible reason is that the initial stage of colonization is to adapt to the new environment, the water content in the matrix is insu cient, the water supply is insu cient, and the water content of pakchoi increases as a whole with watering and replenishing the root system of pakchoi.

Results
The effect of potassium de ciency on the growth status of P. pakchoi in cold and dry areas was signi cant. P. pakchoi treated with potassium-free nutrient solution had the best growth, the largest number of leaves, leaf length, leaf width, leaf area, root length and weight; P. pakchoi treated with 100% potassium de ciency had the smallest plant, leaf length, leaf width, leaf area, root length and weight; P. pakchoi treated with potassium de ciency 50% had the middle growth and development status, and the root ratio was the smallest in d 21.

Discussion And Conclusions
In this study, the effects of potassium de ciency on the growth of pakchoi were studied. The results showed that the growth of pakchoi was severely inhibited by potassium de ciency, such as weak growth, few leaves, yellow leaves, high morbidity and mortality, long leaves, short leaves, small leaf area, fresh weight on the ground and small dry weight on the ground [8][9][10][11][12] This is Sun Ting [13] The effects of different potassium fertilizer on the growth, nutrient absorption and soil nutrient content of pakchoi in greenhouse were similar. The results showed that adding 20% potassium fertilizer on the basis of the main formula could improve the soil condition, improve the quality and adaptability of pakchoi.
The results showed that the root-crown ratio of pakchoi was the smallest in d 21, and the difference between fresh weight and dry weight was the largest in d 35. At the 21st d, the quality difference between the upper part of cabbage and the underground part was the biggest, and the effective complement of potassium fertilizer could effectively alleviate the inhibition of potassium de ciency on the growth of cabbage. The effect of potassium application on the root-to-crown ratio and soluble sugar of pakchoi could be further studied [14][15][16][17] Declarations Ethics approval and consent to participate All authors agree to publish All test data are true and reliable Articles not published, no con ict of interest Funding The cost of publishing is borne by the author Authors' contributions All authors work together to design, collect and analyze data.  Effect of different potassium treatment on water content of cabbage