84 results about "Leaf number" patented technology

The invention provides a method for controlling the growth of tomatoes by establishing a sunlight greenhouse long-season cultivated tomato plant leaf number model. Due to the technical scheme, the method comprises the following steps of: fixing samples; acquiring data; establishing a tomato leaf formation simulation model; and controlling growth management according to the simulation model. The method has the advantages of determining a corresponding relationship between the senescence of tomato leaves and a greenhouse environment and optimizing the regulation and control on the greenhouse environment such as temperature and humidity by using environmental equipment so as to enable the tomatoes in the sunlight greenhouse to grow and develop in a proper environment and realize high-yield and high-quality cultivation.

The invention relates to fertilizer used for tea tree planting, in particular to fertilizer used for tea tree planting and a preparation method and application thereof. The fertilizer obviously increases the yield of tea trees. Compared with the prior art, the length of tips of spring buds of Yong Chuan Xiu Ya tea trees which the fertilizer is applied to is increased by 25.9%; the leaf number is increased by 17.1%; the leaf area is increased by 21.3%; the density of bud heads is increased by 22.7%; the hundred-bud weight is increased by 20.8%. The fertilizer obviously improves the quality of tea leaves of the tea trees. Compared with the prior art, the amino acid content of the spring buds of the Yong Chuan Xiu Ya tea trees which the fertilizer is applied to is increased by 15.1%; the content of tea polyphenol is increased by 14.4%; the content of caffeine is increased by 13.1%.

The invention provides a method for replacing flaveria bidentis by utilizing combination of a sunflower and an alfalfa. In the method, the alfalfa and / or the sunflower is adopted to carry out biological substitution on the flaveria bidentis. The method lowers the emergence rate and the plant height of the flaveria bidentis, reduces the branch number, the leaf number, the biomass and the content of soluble protein of the flaveria bidentis and can fulfill the obvious control function on external invasion of the flaveria bidentis. Seeds of the alfalfa and the sunflower are also easily obtained, and therefore, the planting method is simple and is easy to operate. In addition, the alfalfa is a kind of herbage with high quality, and the sunflower is a kind of important oil crop. The flaveria bidentis population quantity can be controlled and a certain economic value can also be realized by adopting the method.

The invention discloses a flue-cured tobacco planting method for improving tobacco leaf quality by using cedronella. The cedronella and the flue-cured tobacco are inter-planted, and a single flue-cured tobacco planting mode is changed to form a one-plus-one planting mode that a row of flue-cured tobaccos and a row of cedronella are interplanted. An application effect shows that the flue-cured tobacco which grows in the interplanting mode is obviously superior to monocultured flue-cured tobacco in data of plant height, steam diameter, leaf area, effective leaf number, single leaf weight and single plant yield. Through sensory evaluation, the sensory quality of the interplanted flue-cured tobacco is superior to that of the monocultured flue-cured tobacco. Thus, the quality of the flue-cured tobacco can be effectively improved by applying the flue-cured tobacco planting method; and meanwhile, a higher ornamental value is realized by using interplanting of the aromatic crop and the flue-cured tobacco.

The invention provides a special base fertilizer applicable to greenhouse tomato seedling culture. The seedling culture special fertilizer combining an inorganic nutrient, an organic component, a synergistic component, a trace element and an improver is prepared according to the growth fertilizer requirement rule in tomato greenhouse seedling culture, the effects of optimization and yield increase are realized in the growth regulation of tomato seedlings, and the cultivation period is shortened; by applying the base fertilizer, the transplanted seedlings can be strengthened so that the plant height, stem thickness, true leaf number and blade number of the tomato reach the good transplanting conditions; meanwhile, the overground and underground parts develop in balance, the root system is developed with white color and multiple fibrous roots, and the root ball is firm and not loose. The preparation and development of the fertilizer are of promotion value to the cultivation technology of the regional processing tomatoes.

The invention provides a new method for tissue culturing chrysanthemum. It employs cold light source (light-emitting diode) as light source, and determines the optimum ratio of red light to blue light and the best light emitting strength. It takes poromeric fluoroethylene resin film as culturing container for tissue culture sprout; and employs rock fiber block as culture medium. The growing speed for tissue culture sprout is one time faster than that with normal culture method. The tissue culture sprout and replanting sprout are characterized by largest plant height, largest leaf number, root number, longest root length and largest dry net weight of haulm and root, high rate of emergence and little pollution rate.

The invention provides a closed recycling rock wool cultivation system. The rock wool cultivation system comprises cultivation grooves, a nutrient solution pond, drip irrigation components, a nutrient solution recycling disinfection subsystem, a monitor unit and a control unit; the nutrient solution pond and the irrigation components are used for the transport of nutrient solution to plants, the nutrient solution recycling disinfection subsystem is used for the disinfection and the recycling of the nutrient solution in the cultivation grooves, the monitor unit is used for the monitoring of environmental parameters and the irrigation and recycling amount of the nutrient solution, the opening and closing of the drip irrigation components are controlled by the control unit based on the monitoring information. The invention also provides a rock wool cultivation control method. The cultivation control method comprises the steps that the initial physio-genesis time is determined based on the initial leaf number at the colonization of the plants; the physio-genesis time after the planting of the plants is calculated based on the temperature values in each day; the total physio-genesis time of the plants is calculated and the fertility period is estimated according to the initial physio-genesis time of the plants and the physio-genesis time after the colonization; nutrient solution is prepared according to the fertility period of the plants; the plants are estimated whether the irrigation should be conducted according to the basis that whether or not the rea-time light accumulation amount is greater than the arranged light accumulation amount.

The invention discloses a fast growing method for bud grafting of a barbadosnut, which comprises a bud grafting method and a management step after the bud grafting, wherein the bud grafting method consists of the steps of scion collecting, stock cutting, bud cutting, bud inserting and binding; and the scion collecting is to collect a branch of the annual or biennial barbadosnut with lignification, half lignification, plump eyes and no diseases and inset pests; leaves on the branch are removed in time when the branch is cut from the barbadosnut; and the branch is wrapped by a wet towel and so on for standby. The bud grafted by the method sprouts ten days earlier and grows quickly; the basic diameter, length and leaf number of a new branch by the method can improve 40.3-50 percent, 150-208.8 percent and 35 to 55 percent respectively compared with those of new branches by other methods after 70 days of the bud grafting.

The invention discloses a tea picking machine based on image processing. The tea picking machine is characterized in that tea is not damaged during picking, and picked tender leaves are automaticallylayered. The invention also discloses a working method of the tea picking machine based on image processing. According to the method, three-dimensional models of tea ridges and the tender leaves are constructed through analysis of images, the tender leaves are precisely located, and picking arms carry out breaking-type picking on the tender leaves, so that precise picking of the tender leaves is realized. The tea picking machine has the following advantages that the tea picking machine does not damage tea trees and the tender leaves, the bud-leaf number ratio can be freely selected for pickingthe tender leaves, the fresh-keeping performance for storing the tender leaves is great, the picking efficiency is high, and the machine can reach the ends of the tea ridges, automatically stop and send out an alarm when encountering obstacles.

The invention discloses a flue-cured tobacco planting method for improving tobacco leaf quality by using hyssopus officinalis. The hyssopus officinalis and the flue-cured tobacco are inter-planted, and a single flue-cured tobacco planting mode is changed to form a one-plus-one planting mode that a row of flue-cured tobaccos and a row of hyssopus officinalis are interplanted. An application effect shows that the flue-cured tobacco which grows in the interplanting mode is obviously superior to monocultured flue-cured tobacco in data of plant height, steam diameter, leaf area, effective leaf number, single leaf weight and single plant yield. Through sensory evaluation, the sensory quality of the interplanted flue-cured tobacco is superior to that of the monocultured flue-cured tobacco. Thus, the quality of the flue-cured tobacco can be effectively improved by applying the flue-cured tobacco planting method; and meanwhile, a higher ornamental value is realized by using interplanting of the aromatic crop and the flue-cured tobacco.

The invention relates to a method for promoting growth of mongolian bluebeard by inoculating arbuscular mycorrhizal fungi. The method comprises the steps of seed collecting processing, germinating and inoculating, growth condition observing and infection determining. Experimental results show that glomus mosseae and glomus etunicatum are inoculated to the mongolian bluebeard separately, and several of important growth indexes such as the average plant height, the average growth rate, the clump width and the leaf number of mongolian bluebeard plants are apparently higher than those of two non-inoculated control groups and other four AM fungus treatment groups; meanwhile, the glomus mosseae and the glomus etunicatum have the high infection rate and infection intensity on the mongolian bluebeard, and therefore the significant promoting action on the growth of the mongolian bluebeard inoculated with the glomus mosseae and the glomus etunicatum is achieved. It is also expected that the significant promoting action on the growth of the mongolian bluebeard is achieved when the glomus mosseae and the glomus etunicatum are simultaneously inoculated on the mongolian bluebeard.

The invention discloses a high-yield environmental-protection eggplant cultivation method. The method comprises the following steps: sandy loam soil with no eggplants planted in the preceding crop is selected, soil preparation is carried out, a special fertilizer for eggplants is applied, ridges with a row distance of 40 to 60cm and a height of 16 to 20cm are made through deep tillage and leveling, a greenhouse is built, plump eggplant seeds are selected, seeding boiling, temperature reduction, immersion, cleaning and germination are carried out until 40 to 55% of seeds reveal white, seeding is carried out, fine soil covers the seeds, when a seedling has 4 to 5 leaves, the seedling is put to a cold frame, the nutrient area kept for a single plant is 5*15cm, a small plastic greenhouse covers the seedlings, the temperature is controlled to be 24 to 28 DEG C, ventilation cooling is carried out after rejuvenation, field planting is carried out when the seedling has a height of 20 to 25cm and a leaf number of 6 to 10, the temperature is controlled to be 30 to 35 DEG C and the soil humidity is controlled to be 70 to 85% after field planting, and harvesting is carried out when the eggplants are mature. The method of the invention has the advantages that the cost is low, the yield is high, and the environment is not polluted.

The invention discloses a method for promoting cutting propagation of clematis--Cardina Rouge. The method comprises the following steps: (1) variety selection; (2) collection and treatment of cuttings; and (3) management after cuttage. The method in the invention provides certain references for accelerating the application of clematis in gardening and meeting market demands. The method for promoting cutting propagation of the clematis-the Cardina Rouge provided by the invention adopts treatments with semi-lignified branches, a concentration of 2000 mg / L of IBA and 15 seconds of dipping time, so survival rate, seedling height and leaf number reach highest levels, wherein the survival rate is 67.7%, the seedling height is 54 cm, and the leaf number is 10.66 leaves.

The invention discloses a herbicide composition and an application thereof, and relates to the technical field of pesticide compounding. The herbicide composition is prepared from the following effective components including a component (A) and a component (B), wherein the component (A) is agroxone or a derivative thereof, the component (B) is arbitrary one of flazasulfuron, pyrazosulfuron-ethyl, halosulfuron-methyl and trifloxysulfuron, and the weight ratio of the component (A) to the component (B) is 1:70-70:1. The herbicide composition has four characteristics that 1, the herbicide composition is capable of effectively lowering the application amount of each single agent and delaying the drug resistance of a plant and is fast in quick action and long in persistent period; 2, the herbicide composition is capable of efficiently preventing and eliminating elder broadleaf weeds, sedges or grassy weeds with the leaf number of 7 or less and has the synergistic interaction; 3, the herbicide composition is capable of expanding a weed control spectrum, and especially is capable of preventing and eliminating sweet clover and other difficult-to-control leguminous weeds; and 4, the herbicide composition is highly safe to lawns. The herbicide combination is used for prevention and cure of lawn weeds for the first time.

The invention relates to a celery seedling raising matrix and a preparation method thereof, and belongs to the field of agricultural seedling raising technology. Raw materials of the celery seedling raising matrix comprise vegetable stubble compost product, turf and vermiculite in a volume ratio of 4-6: 2: 2-3, wherein the vegetable stubble refers to red pepper stubble, cucumber stubble and common head cabbage stubble; and the stubble refers to plants or plant tissues abandoned in fields after picking. The matrix is most suitable for raising celery seedlings, and the raised celery seedlings are superior to that raised by the conventional seedling raising matrix on the aspects of root system activity, leaf number, dry weight of complete seedlings and yield after field planting. The seedling raising matrix of the invention reduces the using amount of the turf, so the matrix is favorable for saving turf resources, fulfills the purposes of resource recycle of the vegetable stubble and reduction of environmental pollution, and has obvious economic benefit, social benefit and ecological benefit.

The invention relates to the field of plant molecular biology, in particular to a calycanthus praecox gen CpAP1, a protein for encoding the gene and application. The calycanthus praecox blossoming keygene CpAP1 is obtained through cloning, a 534bp open reading frame is obtained, and 177 amino acids are encoded. It is found that after gene transformation is conducted on wild type arabidopsis thaliana, three strains of transgenic arabidopsis thaliana have the rosette leaf number obviously smaller than that of the wild type (WT) compared with the wild type arabidopsis thaliana; meanwhile, the sprouting time, first-flower blossoming time and first-pod forming time of a transgenic plant are obviously earlier than those of the wild type. It is found that after transformation is conducted on anarabidopsis thaliana mutant ap1, the phenotype of the mutant ap1 is restored. It is shown that the gene has a function of promoting plant blossoming and has the functions of typical A-type genes in flower developing models ABCDE, and the development of plant calyx and petals is adjusted.

The invention discloses a mixed substrate for cultivation of Sedum lineare. The mixed substrate is prepared by mixing prefabricated decomposed compost and perlite, and the volume proportion of mixture of decomposed compost and perlite is 5:1. The pH value of the mixed substrate is 6.8, conductivity is 1.162.7uS / cm, unit weight is 0.6g / cm<3>, total porosity is 60.5%, ventilation gap is 28.4%, water-holding pore is 32.1%, organic matter is 53.4%, nitrogen is 2.5%, and phosphor is 0.7%. The invention also discloses a preparation method of the mixed substrate for cultivation of Sedum lineare. Urban garden greening waste and waste life sludge are mixed, decomposed compost and perlite are prepared for roof greening cultivation substrate, the substrate is suitable for roof growth of Sedum lineare with good cultivation effects; unit weight, porosity, contents of organic matters, nitrogen and phosphor and other characteristics satisfy requirements of roof greening cultivation medium, average branch length, leaf number, leaf width, leaf area and other growth vigor indices of cultivated Sedum lineare are obviously better than the indices of Sedum lineare cultivated by peat substrate and garden soil substrate, and the cultivation effects are good.

The invention discloses a flue-cured tobacco planting method for improving tobacco leaf quality by using monarda didyma. The monarda didyma and the flue-cured tobacco are inter-planted, and a single flue-cured tobacco planting mode is changed to form a one-plus-one planting mode that a row of flue-cured tobaccos and a row of monarda didyma are interplanted. An application effect shows that the flue-cured tobacco which grows in the interplanting mode is obviously superior to monocultured flue-cured tobacco in data of plant height, steam diameter, leaf area, effective leaf number, single leaf weight and single plant yield. Through sensory evaluation, the sensory quality of the interplanted flue-cured tobacco is superior to that of the monocultured flue-cured tobacco. Thus, the quality of the flue-cured tobacco can be effectively improved by applying the flue-cured tobacco planting method; and meanwhile, a higher ornamental value is realized by using interplanting of the aromatic crop and the flue-cured tobacco.

The invention discloses a method and a system for predicting the aboveground biomass of woody plants. The method firstly obtains input vectors (stem length, leaf number and root number of woody plants) and output vectors (fresh weight of stem and leaf and dry weight of stem and leaf of woody plants) of the BP neural network; constructing a BP neural network model for predicting aboveground biomassaccording to the input vector and the output vector; then the BP neural network model is trained in cycles according to several training samples, and the trained BP neural network model is generated,which can be directly used to predict the aboveground biomass of woody plants (fresh weight and dry weight of stem and leaf). The trained BP neural network model selects the phenotypic characteristics of woody plants (stem length, leaf number and root number) as independent variables, thus reducing the complexity and acquisition time of sample data acquisition, and eliminating the need of consuming a large amount of manpower and material resources; because of the close relationship between phenotypic characteristics and aboveground biomass, the prediction results have high accuracy.

The invention relates to the field of the greenhouse crops, and specifically relates to a computation method of a greenhouse crop leaf area index. The computation method comprises the following steps:dividing each plant of crop as a top layer, a middle layer and a bottom layer from top to bottom according to the height, recording the total number of the leaf in each layer when measuring every time; performing the characteristic length measurement by selecting the maximum leaf and the minimum leaf in each layer, and respectively computing the leaf area of the maximum leaf and the leaf area ofthe minimum leaf in each layer, thereby obtaining the leaf area average value, and taking the leaf area average value as the representative leaf area of the leaf characteristics at this layer; accumulating product values of the representative leaf area of various layers and the total leaf number of the layer to obtain the total leaf area of the single plant of crop, namely solving the leaf area index of the crop. The leaf area fitting value and the actual value fitting are extremely high, the solved leaf area index accuracy is high, the measurement process is simple in operation, and instrument use cost and the manpower cost are low.

The invention relates to a method for promoting growth of Poacynum pictum by inoculating arbuscular mycorrhizal fungi. The method comprises the following steps: collecting and processing seeds; sprouting and inoculating; observing the growth situation; measuring infection. An experimental result proves that the four important growth indexes, namely, average plant height, average growth rate, cluster width and leaf number of the Poacynum pictum plant, after the Glomus mosseae is inoculated with Poacynum pictum, are obviously higher than the four important growth indexes of two non-inoculating contrast groups and other AM fungi treating groups. Meanwhile, the infection rate and infection strength of the Glomus mosseae to the Poacynum pictum are higher than the infection rate and infection strength to all the other treating groups, so that the growth for the strain after the Glomus mosseae is inoculated with Poacynum pictum is obviously boosted.

The invention discloses Aspergillus niger SICU-33 capable of promoting plant growth and application thereof. The preservation number of the Aspergillus niger SICU-33 disclosed by the invention is CCTCC NO: M2019778, and the ITS sequence of the Aspergillus niger SICU-33 is SEQ NO.1. The strain not only can obviously inhibit the growth of plant pathogenic fungi, but also can promote the growth of plants, increases the leaf number, stem diameter, maximum leaf width, maximum leaf length, fresh leaf weight, fresh root weight, root length and leaf area of corn, and has a good application prospect.

The invention discloses a flue-cured tobacco planting method for improving tobacco leaf quality by using sweet ocimum basilicum. The sweet ocimum basilicum and the flue-cured tobacco are inter-planted, and a single flue-cured tobacco planting mode is changed to form a one-plus-one planting mode that a row of flue-cured tobaccos and a row of sweet ocimum basilicum are interplanted. An application effect shows that the flue-cured tobacco which grows in the interplanting mode is obviously superior to monocultured flue-cured tobacco in data of plant height, steam diameter, leaf area, effective leaf number, single leaf weight and single plant yield. A specific aroma component of elemene of the sweet ocimum basilicum is detected in the fresh interplanted flue-cured tobacco leaves, and related components are not detected in the monocultured cigarette. Through sensory evaluation, the sensory quality of the interplanted flue-cured tobacco is superior to that of the monocultured flue-cured tobacco. Thus, the quality of the flue-cured tobacco can be effectively improved by applying the flue-cured tobacco planting method; and meanwhile, a higher ornamental value is realized by using interplanting of the aromatic crop and the flue-cured tobacco.

The invention discloses a maize molecular marker and application thereof to detection of relevant characters of the blossoming period of maize. The maize molecular marker is (A1) or (A2) or (A3), wherein (A1) is a DNA fragment expressed as the sites 42-401 in a sequence 1 of a sequence table; (A2) is a DNA fragment obtained by substituting and / or deleting and / or adding one or several nucleotides of the DNA fragment of (A1); the homoousia between the DNA fragment of (A2) and the nucleotide sequence defined by (A1) is 90% or is greater than 90%; (A3) comprises the DNA fragment of the (A1) or (A2). Experiments prove that the blossoming period, the plant height and the leaf number of the maize with two chromosomes which contain the DNA fragment expressed as the sites 42-401 in the sequence 1 of the sequence table are obviously less than that of the maize with two chromosomes which do not contain the DNA fragment expressed as the sites 42-401 in the sequence 1 of the sequence table, so thatthe experiments show that the maize molecular marker can be used for identifying the blossoming period, the plant height and the leaf number of the maize.

The invention discloses a flue-cured tobacco planting method using lavender to improve quality of tobacco leaves. The method includes the steps of making use of interplanting between the lavender and flue-cured tobaccos, changing a single mode of flue-cured tobacco planting, and forming a '1+1' planting mode of planting one row of flue-cured tobaccos and one row of lavender. The application effects indicate that the flue-cured tobaccos which grow in an interplanting mode are obviously superior to the flue-cured tobaccos which grow in a single planting mode in data of plant height, stem diameter, leaf area, effective leaf numbers, single leaf weight and single plant yield. The detection results indicate that beta-ocimene is detected in a tobacco sampling in an interplanting mode, and the beta-ocimene is not detected in the tobacco through monoculture, so the tobacco leaves can absorb aroma components of the lavender to some extent in the interplanting mode. Through sensory evaluation, the sensory quality of the flue-cured tobaccos in the interplanting mode is superior to the flue-cured tobaccos through the monoculture. Therefore, the flue-cured tobacco planting method can effectively promote quality of the flue-cured tobaccos, and has high ornamental value due to the adoption of interplanting between aromatic crops and the flue-cured tobaccos.

The invention discloses a method for improving watermelon seedling breeding quality and efficiency. The method comprises steps of seed treatment, seedling breeding medium preparation, seed sowing andseedling breeding, transplanting, and the like. Due to adoption of a seed soaking liquid, the disease resistance of watermelons can be improved, metabolism and accumulation of physiological active substances in seeds can be promoted, enzymatic activity of seeds can be improved, and seed germination can be accelerated; in addition, the bud rate and the bud quality of watermelon seeds can be improved. With reasonable matching of raw materials in a seedling breeding medium, medium environments can be improved, medium permeability can be improved, acid / alkali balance of the medium can be adjusted,rice nutrient and trace elements can be provided for seedlings to grow, and the medium is applicable to growth of watermelon seedlings. Tests show that the seedling breeding method disclosed by the invention is applicable to watermelon seedling breeding, the bud rate of the watermelons can be remarkably increased, the budding time can be remarkably shortened, the survival rate of seedlings can beincreased, performance indexes such as plant heights, stem thicknesses and leaf numbers can be remarkably improved, and good social and economic benefits can be made.

The invention provides a method for preparing a tomato soilless culture substrate. Corn straw is obtained, air-dried and smashed, obtained straw particles are placed in a preprocessing solution to be cooked and filtered, then the preprocessed particles are added into a phosphate buffering solution containing compound enzyme to be subjected to extraction, enzyme deactivation and filtering, finally the enzymolyzed particles are mixed with chicken manure, diammonium hydrogen phosphate, magnesium sulfate, manganese sulfate, chitosan, nicotinamide, gypsum and water are added after high-speed diffusion, high-temperature static composting and airing are conducted, and the substrate is obtained, wherein the preprocessing solution is an aqueous solution of calcium hypochlorite, sodium bicarbonate, urea, sodium chloride, disodium 5'-ribonucleotide, potassium sorbate, pregelatinized starch, calcium nitrate terahydrate and formic acid. By means of the culture substrate prepared through the method, tomato seedlings grow strongly, plant height, stem thickness, leaf number, seedling index and other indexes are obviously better than those of seedlings cultured with turf, and the yield of single tomato plants and quality of obtained fruits are obviously higher than those of tomatoes cultured with turf.

The invention discloses a flue-cured tobacco planting method for improving tobacco leaf quality by using rosmarinus officinalis. The rosmarinus officinalis and the flue-cured tobacco are inter-planted, and a single flue-cured tobacco planting mode is changed to form a one-plus-one planting mode that a row of flue-cured tobaccos and a row of rosmarinus officinalis are interplanted. An application effect shows that the flue-cured tobacco which grows in the interplanting mode is obviously superior to monocultured flue-cured tobacco in data of plant height, steam diameter, leaf area, effective leaf number, single leaf weight and single plant yield. A plurality of components such as camphene, cineole, terpineol, verbenone, nerol, 1, 7, 7-trimethyl-bicyclo [2.2.1] heptyl-2-taraxeryl acetate and caryophyllene are detected in the fresh interplanted flue-cured tobacco leaves, and related components are not detected in the monocultured cigarette. Through sensory evaluation, the sensory quality of the interplanted flue-cured tobacco is superior to that of the monocultured flue-cured tobacco. Thus, the quality of the flue-cured tobacco can be effectively improved by applying the flue-cured tobacco planting method; and meanwhile, the land utilization rate is improved and a higher ornamental value is realized by using interplanting of the rosmarinus officinalis and the flue-cured tobacco.

The present invention relates to a design method for a root thickness of an end-contactless few-leaf root-enhanced sub-spring, and belongs to the technical field of suspension leaf springs. According to the method, the thickness of a flat straight section of a sub-spring root of end-contactless few-leaf root-enhanced main and sub springs with a variable cross section can be designed according to a structure parameter of each leaf of main spring, a length and a leaf number of a sub-spring, a thickness ratio of an inclined line segment of the sub-spring and a thickness ratio of a parabolic line segment, an elastic modulus, and a main and sub spring composite stiffness design requirement value. It can be known by instances and simulation verification that the design method for the root thickness of the end-contactless few-leaf root-enhanced sub-spring, which is provided by the present invention, is correct, and an accurate and reliable sub-spring root thickness design value can be obtained, and a reliable design method is provided for design of the end-contactless few-leaf root-enhanced main and sub springs, and by using the method, the design level, product quality and performance of the few-leaf main and sub springs with the variable cross section as well as vehicle driving smoothness can be improved. Moreover, design and experiment costs can be lowered, and product development can be sped up.