The Effects Of Different Sowing Dates On The Growth And Yield Of Radix Isatidis In Daqing Area

The experimental research in this paper is based on the environmental conditions in Daqing and the current status of planting and management of Isatidis Radix.Through studying the seed germination rate,germination potential,physiological and biochemical indexes of Isatidis Radix and seedlings of Isatidis Radix at different seeding temperatures at different seeding stages,the agronomic characteristics of isatis root growth stage were studied.The traits and the effects of changes in dry matter accumulation were used to determine the suitable sowing time?ambient conditions—temperature?of Isatidis Radix.To find a reasonable timely planting program to solve the current environmental restrictions on the production of Isatidis Radix cultivation in Daqing area,and to provide a theoretical basis and reference for the actual efficient cultivation and production of Isatidis Radix.The test method of this thesis is divided into two parts,field actual production test and indoor artificial simulation test.The field experiment was conducted at the Lufeng Garden Experimental Base of Heilongjiang Bayi Agricultural University in Daqing City.The relevant physiological and biochemical indexes and changes in indicators of Isatidis Radix growth at different sowing dates were measured and analyzed during the whole growth cycle of Isatidis Radix.Artificial culturing environment was set up in the horticultural laboratory of Heilongjiang Bayi Agricultural University's College of Agriculture.Different temperature gradients were used to measure the seedling growth of Isatidis Radix,and the germination rate,physiological and biochemical indicators were measured to explore the effects of different temperature and environmental factors on the seedling stage of Isatidis Radix root seedlings.The effects of growth and production now yield the following main results:?1?The effects of different temperatures on the morphological indexes of Isatidis Radix seedlings under artificial conditions indicated that:In the range of 10°C-25°C,the temperature increase can promote the growth of Isatidis Radix seedlings,and the Isatidis Radix root germination rate and average radicle The plant height,seedling length,and cotyledon width of seedlings showed an upward trend with increasing temperature.At 25°C,the germination rate,average radicle length,seedling height,cotyledon length,and cotyledon width were all tested.The maximum value was reached within the time range.The soluble sugar content in the seedling stage decreased with the increase of temperature,and the content reached 11.75%in the 30th day at 10°C.The chlorophyll content increased with the increase of temperature,and reached the level of 26.82 at 20°C for the 30th day.Mg.g^-1.?2?The changes in agronomic traits of Isatidis Radix at different sowing dates in field experiments showed that the rhizome of the length of main root and the rhizome of main rhizome all showed the trend of“first fast and then slow”,and there was a big difference.The absolute length of main root was The sowing was highest on May 20th and reached 0.57cm·?d·plant?^-1from June 24 to July 22.The main rhizome coarseness trend lags behind the root root length,and May 20 treatment increases from July 22 to August 5.The speed reached0.0286cm·?d·plant?^-1.Early sowing was not conducive to the growth of leaves.The dynamic changes of the maximum leaf length of Isatidis Radix at different sowing dates showed a pattern of rapid growth in the early stage and stable in the middle and later stages.?3?The field leaf area index and chlorophyll content showed a single-peak curve during the whole growth period of Isatidis Radix at different sowing dates.The sowing date was too early.Isatidis Radix caused premature senescence due to low temperature at the seedling stage,affecting the formation of photosynthetic product at later stages.On May 6th,the sowing treatment reached the maximum value of 520.81cm2 before and after August 5.After September,it was 39.3%to 50.26%lower than that of other sowing dates.The chlorophyll content of the sowing date of May 13 was obviously after September.Above May 6,it reached40.28%.The dynamic regulation of dry matter accumulation and distribution in organs of Isatidis Radix indigotica is basically the same.Proper early sowing can improve the economical yield of Radix Isatidis root cultivation to a certain extent;the yield of Isatidis Radix fresh root reaches a maximum value of 12060.85 kg during the sowing period of the field experiment on May 20.·hm^-2;under the sowing date of May 13,the yield of Isatidis Radix dry roots reached a maximum of 5,434.78 kg·hm^-2;during the harvest period of May 6,the Isatidis Radix dryness rate reached the maximum during the harvest period.52.6%.Based on the above test results,the growth temperature of Isatidis Radix seedlings is the most suitable at 25°C,and the production of Isatidis Radix in Daqing Region is reasonable during the production period from May 13 to May 20.