| As people’s consumption levels continue to increase,the diet structure continues to diversify,and the demand for vegetables is also becoming increasingly diversified.Therefore,it is very important to introduce new special and high-quality vegetables.Watercress(Nasturtium officinale Br.)is native to Europe.After being introduced into China,it has been widely planted in Guangdong and Guangxi and gradually promoted from south to north.However it is rarely introduced and cultivated in Nanjing,especially suitable for cultivation in different seasons.There are few researches on varieties,and the research on soilless cultivation technology is even less reported.For this reason,this study selected’Yingke’,’Yunnan Daye’,’British Daye’and’Green Golden Blue’watercress as materials,using organic-inorganic mixed substrates and inorganic substrates,which are suitable for summer in Nanjing.Screened watercress varieties,and determine suitable substrates for watercress soilless cultivation;used the selected substrates to screen the suitability of 4 watercress varieties in autumn;selected high-yield and good-quality watercress in autumn.’British Big Leaf’is the test material.With distilled water as the control,set 5 nutrient solution concentrations of 1/8 times(1/8T),1/4 times(1/4T),1/2 times(1/2T),1 times(1T),and 3/2 times(3/2T)of garden test to study the characteristics of growth,physiology,quality and yield of watercress at different concentrations,and determine the nutrient solution concentration suitable for soilless cultivation of watercress.Based on the experiment and cultivation experience,the technical regulations for simple soilless cultivation of watercress were summarized.The main findings are as follows:1.Comparing the growth of four varieties of watercress on different cultivation substrates in summer,it is found that the growth,yield and quality of watercress in inorganic substrates are better than those in organic-inorganic mixed substrates;’Lvjinlan’grow better than the other 3 varieties.The characteristics of rapidness and high heat resistance are superior to the others.Under the condition of inorganic substrate cultivation,its nitrate content is only 110.99 mg/g,which is equivalent to a yield of 1278.15 Kg/667m~2.Therefore,’Lvjinlan’can be used as the main popularized variety of watercress in summer in Nanjing area for soilless cultivation.2.In the autumn soilless cultivation in Nanjing area,the‘British Big Leaf’shows the characteristics of rapid growth,high tillering degree,high yield and good quality,which is better than the other 3 varieties.The number of leaves of‘British Big Leaf’can reach up to 30,which translates to a maximum yield of 1852.86 Kg/667m~2.Therefore,’British Big Leaf’is more suitable for soilless cultivation in autumn in Nanjing.3.The concentration of nutrient solution in 5 test gardens was set.Within the range of nutrient solution concentration in this test garden,photosynthetic intensity,root vitality,and yield of watercress increased first and then decreased with the increase of nutrient solution concentration;With the increase of nutrient solution concentration,the content of soluble fiber,sugar,vitamin C also increased and then decreased.While the content of soluble protein and nitrate showed a continuous increase.Among them,watercress showed high seedling index,strong photosynthetic capacity,and high root vitality at 1/2 times and 1times the nutrient solution concentration;The content of soluble sugar,soluble protein,and vitamin C was significantly higher than the control;at 1/2 times the nutrient solution concentration,the electrolyte permeability and malondialdehyde content of watercress are lower,while at 1 times the nutrient solution concentration,the nitrate content of watercress is higher,which is 202.97mg/g;the yields of the two nutrient solution concentrations were similar,which were increased by 56.5%and 51.5%.Comprehensive analysis of growth,yield,quality and other indicators,1/2 times nutrient solution is more suitable for watercress soilless cultivation. |
PDF Full Text Request