Nghiên cứu đặc điểm nông sinh học và một số biện pháp kỹ thuật để phát triển hai dòng chè CNS – 1 41 và CNS – 8 31 tại các tỉnh miền núi phía bắc tt tiếng anh

MINISTRY OF EDUCATION MINISTRY OF AGRICULTURE AND AND TRAINING RURAL DEVELOPMENT VIETNAM ACADEMY OF AGRICULTURAL SCIENCES TRINH THI KIM MY STUDY ON AGRI-BIOLOGICAL CHARACTERISTICS AND SOME TECHNICAL MEASURES TO DEVELOP TWO TEA CLONES CNS-1.41, CNS-8.31 IN NORTHERN MOUNTAINOUS PROVINCES OF VIETNAM Speciality: Crop science Code: 62 01 10 SUMMARY OF DOCTORIAT THESIS Scientific supervisers: Dr Nguyen Huu La Dr Le Van Duc HA NOI - 2019 Thesis completed at: VIETNAM ACADEMY OF AGRICULTURAL SCIENCES Scientific supervisors: Dr Nguyen Huu La Dr Le Van Duc Advocate 1: Advocate 2: Advocate 3: The thesis will be defended before Council for thesis assessment at Institutional level held at Vietnam Academy of Agricultural Sciences at …… hour ……minute, day …… month…….year This Thesis can be referred to at: National Library Library of Vietnam Academy of Agricultural Sciences Library of Northern Mountainous Agriculture and Forestry Science Institute INTRODUCTION Necesity of the thesis to be studied Tea is a perennial industrial tree, playing an important role in the crop structure of the Northern midland provinces of Vietnam Tea has an economic tenure lasting from 30 to 40 years, suitable for the climate and soil in the midland and mountainous areas, planted in 34 provinces and cities of the country, creating considerable profits and jobs for over million people in tea areas Tea plantation also plays a mainly role in greening bare land and bare hills, minimizing erosion In recent years, the Northern Mountainous Agriculture and Forestry Science Institute has applied biotechnology in the selection of tea breeding by molecular markers, combining embryo rescue and tissue culture technology two new clones of tea CNS-1.41 and CNS - 8.31 showed many superior features, high and stable bud yield, good tolerance and quality Due to the outstanding elite characteristics, two new tea clones CNS - 1.41 and CNS - 8.31 can completely meet the requirements of production for improving productivity and quality of tea In order to quickly develop these two clones of tea into production, it is necessary to systematically assess the growth, productivity, quality and identify appropriate technical measures to promote the potential of new varieties Stemming from the above issues we conduct research topics: “Study on agri-biological characteristics and some technical measures to develop two tea clones CNS-1.41, CNS-8.31 in Northern mountainous provinces of Vietnam” Objectives of the thesis 2.1 General objectives Study the characteristics of growth and development and some technical measures to complete the process and quickly bring the two clones of tea CNS-1.41, CNS-8.31 into production in the Northern mountainous region 2.2 Specific objectives - Evaluating the characteristics of growth and development of two clones of tea CNS-1.41 and CNS8.31 - Identify some main technical measures to develop two new tea clones into production Scientific and pratical significance of the thesis 3.1 Scientific significance Systematically studying agronomic, biological characteristics and technical measures to develop two new tea clones CNS-1.41 and CNS-8.31 created by molecular techniques and tissue culture, hybrid embryos of tea plants; adding scientific materials on the adaptability of two tea clones CNS-1.41 and CNS8.31 in some ecological sub-regions of the Northern mountainous region; supplement materials with valuable scientific theories and teach tea plants 3.2 Practical significance Research results on two tea clones CNS-1.41 and CNS-8.31 serve as a scientific basis for the arrangement of seed structure and tea product development orientations for the Northern midland and mountainous areas; as a basis for building and completing the production process of two new tea clones CNS-1.41, CNS-8.31 to apply in production, improving the current tea production efficiency Novel aspects of the study For the first time, systematically providing data on growth, yield, quality and farming techniques for two new tea clones CNS-1.41 and CNS-8.31 created using molecular techniques and Cell tissue culture technology Identifying major agro-biological characteristics of two new tea clones CNS-1.41, CNS-8.31 as a scientific basis for cultivation and processing in tea production; Identify two new tea clones CNS-1.41 and CNS-8.31 that are capable of growing and developing well, meeting the requirements of current tea production to replace old tea varieties with new ones with high yield and good quality: Easily asexually propagated with a high propagation coefficient (the 3-year-old tea garden has a yield of 2.92-3.66 million cuttings/ha); the second year after planting, it can be put into harvest, the productivity reaches 5.22 - 7.36 fresh leaves tons/ha; content of tannin 24.47 - 25.51%, of amino acids 2.45-2.56%, of catechin 137.12-145.75% and suitable for processing both green tea (sensory point 16.43-17, 94 points) and good quality black tea (sensory score of 17.5-18.6 points); Identify a number of major technical measures to improve the productivity of tea leaf material quality of two new tea clones CNS-1.41, CNS-8.3: Appropriate planting density from 16.6 to 18.5 thousand trees/ha , double planting method; first shaping felling 15-20 cm the hight stem, the longth branches 35 cm above the ground makes of canopy, increase density of shoots, early high yield; mineral fertilizers increased 40%, tea yield higher than the control 50.89 - 51.23%, profits increased 60.78-76.32%; Building up a number of models of planting two new clones of tea with high efficiency in production in Phu Tho, Tuyen Quang and Yen Bai provinces Structure of the thesis The thesis consists of 175 pages uncounted the references and appendix: Introduction (5 p.); Chapter I Over all documentation concerned and scientific basic of the thesis (47 p.); Chapter II Material, content and methods of the study (13 p.); Chapter III Results and discussion (80 p.), There are 33 tables, 22 pictures and figures; Conclusions and recommendations (4 p.); 145 scientific works published in Vietnam and outsides cited were involved in the document, including 49 Vietnamese documents, 78 English documents, 18 Russian documents; The appendix has appendices, appendices CHAPTER OVER ALL DOCUMENTATION 1.1 Scientific basis of the topic 1.1.1 Characteristics of growth and development of lines and varieties of tea 1.1.2 Main technical measures for tea plants 1.2 Situation of research on tea plants in the world 1.3 Research on tea plants in Vietnam CHAPTER II MATERIALS, CONTENTS AND METHODS OF THE STUDY 2.1 Research materials - CNS-1.41 tea clone: is a clonal tea line selected from a hybrid of the two varieties: Trung Du and Ho Nam, in the form of semi-wooden trunks, early and multiple branches, the tea clone has early germination characteristics from middle of January - CNS - 8.31tea clone: is a clonal tea line selected from a hybrid of green tea varieties: Trung Du and Kim Tuyen, with a semi-misshapen trunk shape, the branching angle is narrower than the CNS-1.41 Two new tea clones were created by combining sexual hybridization, young embryo culture and selection during in vitro culture - Inorganic urea fertilizer 46% N; super-phosphate Lam Thao 16.5% P2O5; KCl 60% K2O; pesticides on the list of allowed use for tea plants - Equipment and tools: Olympus stereo microscope; SPAD-502Plus portable chlorophyll meter; equipment for analyzing biochemical components such as spectrophotometer, titrator, centrifuge, 2.2 Research content 2.2.1 Study the characteristics of growth and development of two new tea clones CNS-1.41 and CNS-8.31 2.2.1.1 Morphological characteristics of the two tea clones 2.2.1.2 Characteristics of growth and development of two new tea clones 2.2.1.3 Productivity and components of productivity 2.2.1.3 The situation of pests and diseases mainly on tea 2.2.2 Research on some major technical measures to develop two new tea clones 2.2.2.1 Study the density and method of planting 2.2.2.2 Researching techniques for cutting two new tea clones 2.2.2.3 Researching techniques of picking two new tea clones 2.2.2.4 Research fertilizer rates N, P, K 2.2.2.5 Studying the breeding ability of two new tea clones 2.2.2.6 Testing two new tea clones at production conditions 2.3 Research Methods 2.3.1 Study the characteristics of growth and development of two new tea lines CNS-1.41 and CNS-8.31 2.3.1.1 Experimental design: Experiment 1: Comparation the two tea clones CNS-1.41 and CNS-8.31 and the LDP1 variety as the control, the area of the experimental plot is 45m2, replicates, arranged completely randomly Planted by cuttings in 2015 in Phu Ho, row spacing 1.5 m, tree spacing 0.5 m Other care follows the process of planting and tending tea according to industry standards (10TCN 446 – 2001) 2.3.1.2 Criteria observed: Tree height (cm); Canopy width (cm); stem diameter (cm); Height of branches (cm); Number of branches of level and level (branches); Leaf length (D) (cm); Leaf width (R) (cm); Leaf area (cm2): Leaf area = (D x R) x 0.7 (0.7 is the experimental coefficient); Chlorophyll content (SPAD) is the value measured by SPAD-502 Plus Time to start growing (days); Growth end time (days); Length of tea shoots: Measure from the 3rd petiole to the top of growth; Weight of three leaves and bud (g/shoot); Density of three leaves and bud (shoots/m2): Count the number of qualified shoots in the frame 25*25cm by points diagonally; Theoretical productivity (tons/ha): number of shoots /one tree * weight of one shoot * number of plants/ha; actual productivity (tons/ha): Weigh the weight from the experimental plot to ha; The ability to produce cuttings from tea varieties: Assessing the number of cuttings per tree, the number of cuttings per branch, the total number of cuttings per ha, the rate of cuttings according to Vietnam standards (TCVN01-124: 2013) 2.3.2 Research methodology of some technical methods for cultivating two tea clones CNS-1.41 and CNS-8.31 2.3.2.1 Experimental design: * Experiment 2: Study the density of planting two tea clones CNS-1.41 and CNS-8.31 The experiment consists of treatments, replications, in a completely randomized block, each plot has an area of 120 m2, the distance between rows and different trees is as follows: Treatments Planting distances (m) Densities of planting Method of planting (thousand/ha) T1(control) 1.50 * 0.40 10 row * 20 trees (single row) 16.6 T2 1.80 * 0.60 row * 13 trees (double rows) 18.5 T3 1.80 * 0.67 row * 12 trees (double rows) 16.6 * Experiment 3: Researching the fertilizing rate for two clones of tea CNS-1.41 and CNS-8.31 at the basic construction stage The experiment consists of treatments, the experimental plot area of 45m2, replicates, is arranged in a completely randomized block The dose of mineral fertilizers (N, P, K) increased gradually compared to the control (the control method applied in Vietnam standard : 10TCN 446: 2001) Mineral fertilizer is applied times per year in February, May and August Treatments Fertilizing dosages (N:P:K) T1(control) 80 kg N + 40 kg P2O5 + 60kg K2O /ha T2 88 kg N + 44 kg P2O5 + 64kg K2O /ha (increased 10%) T3 96 kg N + 48 kg P2O5 + 72 kg K2O /ha (increased 20%) T4 112 kg N + 56 kg P2O5 + 84 kg K2O /ha (increased 40%) Evaluation criteria: tea growth and yield * Experiment 4: Study on prunning techniques for two tea clones CNS-1.41 and CNS-8.31 at the basic construction stage The experiment consists of treatments with different prunning heights, the plot area of 45m2, replicates are arranged in a completely randomized block Evaluation criteria: tea growth and yield Treatments Method of prunning T1(control) Cut down the height of stems 15 cm, side branches 35 cm T2 Cut down the height of stems 20 cm, side branches 35 cm T3 Cut down the height of stems 25 cm, side branches 35 cm The first prunning when the diameter of the stem of tea trees ≥ 1cm, the next prunning above the floor of old prunning about 10cm Evaluate tea growth and yield * Experiment 5: Studying to identify suitable picking technique for two tea clones CNS-1.41 and CNS-8.31 at the basic construction stage Treatments Method of plucking T1 The first picking above the old pruning about 10 cm, the next picking close canopy T2 The first picking above the old pruning about 20 cm, the next picking close canopy T3 (control) The picking according to the process (only picking standard shoots) The expeiment consists of picking treatments with different leaving canopies, the area of the experimental plot is 45m2, arranged in a completely randomized block, replicates * Investigating growth and development, yield and situation of pests and diseases of two tea clones CNS-1.41 and CNS-8.31 in the conditions of provinces: Phu Tho, Tuyen Quang and Yen Bai Experiment 6: Comparation the ability of propagating cuttings of two tea clones in Phu Ho The experiment consists of treasments including clones of CNS-1.41 and CNS-8.31 and LDP1 variety (control) 2.3.2.2 Criteria observed: * Observe the growth and productivity: Diameter of tree stem (cm); Tree height (cm); Width of canopy (cm); Height of branches (cm); Number of branches of level 1, number of branches of level 2; Tea shoot length; Volume of shoots three leaves and bud; Canopy area (m2 ); Densities of picking (shoots/m2 ); Theoretical productivity (tons/ ha); actual productivity (tons/ha) The method of measuring the indicators is as in section 2.3.1 * Evaluate the tea quality: - Quality of tea raw materials: Determination of quality of tea raw materials according to Vietnam standard (VTCVN 1053 71): type (type A): ≤ 10% of medium mature; type (type B): 11 - 20% of medium mature; type (type C): 21- 30% of medium mature; type (type D): ≤ 45% of medium mature + Rate of shoots without buds: At each experimental treasment, take randomly 100g of raw materials, count the number of shoots without buds (%) + The percentage of shoots with buds (%) = the total percentage of shoots (%) - the percentage of shoots without buds (%) + Mechanized composition of tea shoot is the percentage of weight between shoots and buds, leaf 1, leaf 2, leaf and stalk - The biochemical composition of tea shoots was analyzed at the analysis department of soil and food crops quality from Northern Mountainous Agriculture and Forestry Science and Technology Institute Raw materials for biochemical analysis: shoots of two leaves and buds are taken from tea clones/cultivars of 3-year-old tea plants - Quality of tea products: the quality of green and black tea were tasted by the Tasting Council from Northern Mountainous Agriculture and Forestry Science and Technology Institute according to Vietnam standard (10 TCN 745: 2006 and TCVN 3218 – 2012) * Evaluate the tea pests - Investigate green leafhoppers (Empoasca flavescens): use a tray with the size of 25 * 20 * 5cm of the bottom of the tray covered with a layer of mazut oil and place the tray under the canopy of tea tree and beat strongly three times by hand side above, count the number of green planthoppers falling into the tray, calculated mumber of green planthoppers per tray - Investigate the density of beetle (Physothrips setiventris): collect tea leaves in the experimental plot by points diagonally, each point take 20 buds put into PE bags to bring about the number of beetle beetles, calculated mumber of shoots - Investigate the mosquito bugs (Helopeltis theivora): Investigate according to points diagonally, each spot picks 20 shoots, put into PE bags and take to count the number of shoorts with mosquito bugs, calculate the percentage of damaged shoots - Investigation of red spider (Olygonychus cofeae): Collect tea leaves with points diagonally at each corner of 20 leaves for PE bag to take to count the number of spider and calculate the percentage of damaged leaves * Observe the nursery cuttings Survival rate of cuttings; rooting rate; germination rate, rate of outplanting; seedling height; weight of stems, leaves, roots Seedlings for outplanting with standards are 8-10 months of age, tree height is ≥ 22 cm, - leaves, brown stems over 50% 2.4 Methods for statistical data Experimental data were calculated and evaluated by Excel and Srichai Statistics 6.0 CHAPTER III: RESULTS AND DISCUSSION 3.1 Study on characteristics of growth and development of two tea clones CNS-1.41, CNS-8.31 3.1.1 Study on morphological characteristics of two tea clones 3.1.1.1 Morphological characteristics of tea leaves: Observing morphological characteristics, the leaves of the two tea clones CNS-1.41 and CNS-8.31 are very different, the mature leaves of CNS-1.41 with green and yellow colour are similar the leaves of LDP1, the mature leaves of CNS-8.31 with green dark colour; leaf surface shape of CNS-1.41 is rough, the leaf edges are clearly wavy to recognize, the leaf is horizontal; the leaf surface of CNS-8.31 is rough but shallower than the CNS-1.41, the leaf edge is straight, not wavy, the leaf is facing up The leaves of different tea varieties are not only different in shape, colour, but also in their size Research results on leaf size characteristics are presented in table 3.2 Table 3.2 Leaf size of tea clones/cultivars studied Criteria Leaf size Number The Chlorophyll content (spad) Leaf Leaf Leaf of double ratio of length width area veins length to (cm) (cm) (cm ) (double) width CNS– 1.41 13.7a 5.9a 57.6a 8-10 2.29 61.4b CNS– 8.31 10.8b 4.6b 34.9b 8-9 2.35 76.7a LDP1 (control) 9.4b 4.0b 26.3c 7-8 2.34 58.6b CV (%) 8.2 10.7 6.1 7.4 LSD0.05 2.1 1.1 5.4 6.5 Clones/cultivars Leaf length of the CNS -1.41 reached 13.70 cm, the second was the CNS-8.31 at 10.38 cm, equivalent to the length of LDP1 tea leaves; The width of leaves of CNS-1.41 is 5.90 cm, which is larger than that of CNS-8.31 and LDP1 (4.6cm and 4.0cm) Leaf area of the clones/cultivars varied from 26.30 to 57.6 cm2 in which CNS - 1.41 had leaf area of 57.6 cm2, followed by CNS - 8.31 with 34.90 cm, the smallest LDP1 (26.3 cm2) 3.1.2 Research on growing of CNS -1.41 and CNS - 8.31 3.1.2.1 Growth of stems and branches of basic construction period To evaluate the growth of new tea clones, we conducted experiments comparing two clones: CNS- 1.41, CNS-8.31 and LDP1 In the scope of the thesis research, we present the results of growth of tea clones/varieties during the basic construction period The research results showed that two new tea clones grow well, one year old after planting, the survival rate is quite high, from 85.5 to 91.1%, while the control variety LDP1 lives at 85.5%; regarding growth of plant height, the CNS-141 and CNS-8.31 lines were 120.4 and 128.4 cm, and LDP1 was 80.7cm; stem diameter (stem) of the CNS-1.41 and CNS-8.31 reached 1.3cm, the control LDP1 variety reached 0.9cm One year old after planting, these two clones have a root diameter of > 1cm, which is eligible for first cutting while LDP1 has not met the cutting requirements This is one of the characteristics that two new tea clones are early for harvest and have high yield potential; The CNS-141 and CNS-831 have a low branch height of 2-3.6cm, low branch height makes tea trees grow more branches, which is one of the characteristics that make the CNS-1.41 will be wider spreaders later; number of branches of two clones reached 15.9-25.7 branches/tree and 23.6-39 branches/tree Level and level have the decisive meaning to form the basic canopy of tea trees, tea varieties with many branches of level 1, level will have big canopy early and promote the potential of productivity The results of the growth of two clones at age show that they are very strong, especially at one year old enough to be prunned for the first time This could allow new tea clones to be harvested at the second year after planting Table 3.7 Growth characteristics of 3-year-old tea clones/varieties in Phu Ho in 2018 Criteria Clones/cultivars Plant Canopy Stem Shoot Shoot Internode Yield height Width diameter density weight length (tones/ha) (cm) (cm) (cm) (shoots (g) (cm) /m ) a a a CNS-1.41 76.5 180.4 5.4 124.2a 1.02b 5.6b 13.68a CNS-8.31 76.6a 167.6a 4.9a 98.7b 1.18a 6.15a 9.72b LDP1(control) 78.5a 125.7b 3.6b 94.5b 0.91c 4.0c 6.59c CV (%) 6.06 6.7 10.3 9.09 6.1 12.1 14.92 LSD0,05 2.9 23.9 1.01 4.61 0.10 0.54 2.32 Note: the shoot density only counts the shoots that are eligible to be picked (two leaves and bud or more leaves); actual yield was obtained from the plot At the age of after pruning, the two clones developed strongly canopy width, shoot density, early for harvest After age of 2, canopy width of the CNS-141 reached 120.7 cm, larger than CNS-8.31 (93.6 cm) and LDP1 (85.2 cm) Shoot density: the CNS-141 has a density of 121.5 shoots/m2, CNS-81 has a density of 92.5 shoots/m2, while LDP1 has 84.4 shoots/m2 Regarding the productivity of the CNS-141, it was 7.36 tons/ha; CNS-831 reaches 5.22 tons/ha; LDP1 reaches 3.64 tons/ha By the 3rd year, the tea tree has gone through prunning times, the tea ages are regularly picked, so the height of the canopy is stable, the tree height of tea clones/varieties varies from 76.5 to 78, cm The stem diameter and canopy width continue to increase Regarding shoot density, the CNS-141 series had the highest shoot density (124.2 shoots/m2); CNS-831 and LDP1 have similar shoot density Shoot weight, the 11 survival rate was LDP1 with 96.3% After 12 months of planting, the survival rate of plants also changed significantly, survival rates of two clones CNS - 1.41 and CNS - 8.31 were similar, reaching from 97.4% to 100% and higher than LDP1 variety (90.4%) 3.1.6 Assess the possibility of infection with some major pests Pests and diseases are one of factors that greatly affect the growth and development of plants in general and in particular of tea The thesis has evaluated the level of infection with some major pests, the results are presented in Table 3.17 Table 3.17 Situation of some main pests on two tea clones in Phu Ho, 2015 - 2017 Clones/ Greenleaf Red spider Thrips Mosquito bugs cultivars hoppers/tray) (ones/ leaf) (ones/shoot) (%) c c 1.56 b 0.34a CNS-1.41 1.05 0.74 CNS-8.31 1.16b 0.80b 1.68b 0.44a LDP1 (control) 1.28a 0.96a 1.83a 0.61a CV 7.0 7.83 8.59 14.85 LSD0,05 0.03 0.03 0.13 0.17 The results in Table 3.17 showed that the green hopper density in the CNS-1.41 was the lowest, 1.05 ones/tray, the CNS-8.31 was 1.16 ones/ tray and lower than the green hoppers on the LDP1 (1.28 ones/tray); Red spider in the CNS-1.41 is 0.74 ones/leaf, on the CNS-8.31 is 0.80 ones/leaf, the most on the LDP1 variety (0.96 ones/leaf); The highest density of thrips was on LDP1 (1.83 ones/shoot) followed by CNS-8.31 (1.68 ones/shoot) and CNS-1.41 (1.56 ones/shoot); Mosquito bugs bite on CNS-1.41, CNS-8.31 and LDP1 were similar (the percentage of infected shoots ranged from 0.34% to 0.61%) 3.2 Researching some farming methods mainly develops tea clones at the basic construction stage 3.2.1 Study the density and method of planting two new tea clones In order to promote the potential of the variety and identify the techniques for production, the thesis has studied the density and method of planting new tea clones with the density of 1.66 and 1.85 thousand trees/ha, two planting methods are single and double row Results in tables 3.18 and 3.21 Table 3.18 Influence of planting density on the growth of the CNS-1.41 in one year old, in Phu Ho Treatments Survival Height Canopy Height of Stump Number of Number of rate (cm) width (cm) branchs diameter first-class second-class (cm) (cm) branches branches (%) T1(control) T2 a CV% LSD0,05 a 25.84 a 38.42a 42.91 92.82a 118.57a 45.45a 1.91a 1.41a 23.58a 36.38a 120.49a 46.38a 2.54a 1.44a 23.47a 35.51a 8.90 12.80 7.62 6.84 7.81 11.00 11.22 6.90 0.72 0.75 3.70 4.26 5.20 1.22 a 112.66 9.02 2.12 a 93.46 93.17a T3 a Note: T1 (control): 1.5m * 0.4m, single rows, 16.6 thousands/ha T2: 1.8m * 0.6m, double rows, 18.5 thousands/ha T3: 1.8m * 0,67m, two double rows, 16.6 thousands/ha The results in Table 3.18 showed that the CNS - 1.41 of one year old had the survival rate is quite high and similar as the another density, the survival rate is from 92.82 to 93.46% 12 Growth criteria such as tree height, canopy width, branch height, number of first-class branches, and number of second-class branches haven’t differed among the research densities Width of canopy ranges from 42.91 - 46.38cm; The original diameter is from 1.22cm to 1.44cm; height of branches from 1.91cm - 2.54cm; number of first-class branches from 23.47 to 23.84cm, secondary branches from 35.51 to 38.42 branches This result has determined that tea planting density hasn’t affected the development and development of tea trees of age 1, tea trees grow to reach the conditions of shaping and cutting after one year old; In the second year, the planting density affected tea yield, the density of 18.5 thousands/ha, the yield was higher than the density of 16.6 thousands/ha because the greater number of trees and the higher number of shoots; In the third year, besides the influence of the number of trees, there is also the influence of the planting method: double row planting, two double rows will interact with each other differently than single row planting (Table 3.21) Table 3.21 Influence of planting density on yield components and yield of two tea clones at age in Phu Ho, 2018 Clones Treatments of Density Effective Density of Weight N of Theoretical Actual canopy shoots of shoots plucking yields yields (g/shoot) times (tones/ha) (tones/ width (shoots/m ) (cm) CNS-1.41 D1 (control) 1.22 b (times) 112.40 b 1.08 a ha) 17 13.75 b 9.53 b D2 1.50 a 124.60 a 1.05 a 17 18.53a 13.68a D3 1,50 a 115.30 ab 1.05 a 17 17.15 a 12.64 a CV% 5.93 4.08 1.63 5.92 8.43 LSD0,05 0.16 9.53 0.03 1.94 CNS-8.31 D1 (control) 1.20 b 95.66 b 1.23 a 2.01 17 13.33 b 7.69 b D2 1.32 a 102.5 a 1.21 a 17 15.46a 9.72a D3 1.30 a 98.86 ab 1.21 a 17 14.85 a 8.76 ab CV% 3.25 3.27 1.75 5.11 10.20 LSD0,05 0.08 6.48 0.04 1.48 1.77 The results in Table 3.21 showed that two tea clones, at the third year, were completely full canopy (CNS-1.41) or near canopy (CNS-8.31); two planting density 16.6 thousands/ha and 18.5 thousands/ha with the CNS-1.4 which was planted in double row, the effective canopy width is 1.5m and greater than the density of 16.6 thousands/ha but planted in single row; Regarding shoot density, the different planting densities are different, at the 95% confidence level, the planting density is 16.6 thousands/ha and 18.5 thousands/ha, but when planted in a double row, the shoot density is not different, in which density of 18.5 thousands/ha reached 124.6 shoots/m2, while planting density of 16.6 thousands/ha, shoot density reached 115.3 shoots/m2 The lowest density of shoots in planting mode is 16.6 thousands/ha but single row planting is 112.4 shoots /m2; The mass of shoots at the planting densities was similar, reaching 1.05 - 1.08 g / shoot In 2018, the experimental tea picking was 17 times; The yield components are different, so the yield in different density teasments and planting methods is different, whereby planting with the density of 16.6 thousands and 18.5 thousands/ha and double row 13 planting , for equivalent theoretical yields of 18.53 tons and 17.15 tons/ha; The treasment of 16.6 thousands/ha in single row, the lowest yield, reaching 13.75 tons/ha In addition to yield calculations based on yield components, tea shoots were also harvested to assess actual yield, resulting in double rows of similarly productive rows, reaching 13.68 tons and 12.64 tons/ha and higher than single row crops (9.53 tons/ha) For the CNS-8.31 tea clone, the results obtained in the density and planting treasments were similar to those achieved by the CNS-1.41 clone From the collected results, the same density of 16.6 thousands/ha was planted, but double row planting, yield advantage and tea buds were grown evenly The method of double planting is popular in Japan and some countries in the world 3.2.2 Researching techniques for cutting two clones CNS-1.41, CNS-8.31 in the basic construction period Prruing of young tea trees is an important technical measure, which is to cut the main stem and lateral branches to lose the peak growth advantage and stimulate the development of sleeping germs, helping the tea tree have a frame soonly The largest canopy to achieve high yield and improve health for tea plants One year after planting, all young tea plants of the two clones reached a height of over 1m and a stump diameter of over cm is eligible for initial shaping Results are presented in Table 3.22 Table 3.22 Effect of cutting techniques to the growth of the CNS-1.41, CNS - 8.31 in two years old in Phu Tho Clones Treatments Height Canopy Stump Density of Weight Yields of prunning (cm) width diameter shoots of shoots (tones/ha) (cm) CNS – 1.41 CNS – 8.31 a (shoots/m ) a (g/shoot) 3.25 129.60 a 1.20a 9.82a Prunning 68.2 Prunning 68.7a 127.0a 3.07a 119.12a 1.28a 9.24a 75.6a 120.3b 2.48b 118.05a a 8.14b CV% 9.40 6.91 8.52 11.6 4.7 6.96 LSD0,05 14.40 13.15 0.49 15.3 0.3 0.90 Prunning 62.2a 116.3a 3.52a 121.09a 1.27b 7.64a Prunning 71.2a 110.0a 2.95a 109.57b 1.32a 6.82b Prunning a a b Prunning (control) 135.5 (cm) a c 1.33a 5.42c 73.4 103.6 2.14 CV% 10.4 8.4 0.78 9.4 6.4 9.3 LSD0,05 16.02 17.40 0.92 11.2 0.2 1.32 (control) 97.81 1.17 Note: Prunning – Cut main stem 15 cm and lateral branch 35 cm Prunning – Cut main stem 20 cm and lateral branch 35 cm Prunning – Cut main stem 25 cm and lateral branch 35 cm The results showed that, after prunning, tea trees grow well Experimental tea cultivation in the second year immediately after cutting has been harvested, yielding quite high For the CNS-1.41, the density of shoots among the treasments was equivalent to 118.05 - 129.60 shoots/m2, the Prunning reached 129.60 shoots/m2, followed by the Pruning 119.12 shoots/ m2 is the 14 same as that of control reaching 118.05 shoots/m2 The yield in the Pruning reached 9.82 tons/ha, the Prunning reached 9.24 tons/ha higher than control (only reached 8.14 tons/ha) For the CNS - 8.31 series, the highest shoot density in the Prunning reached 121.09 shoots/m2, followed by the Prunning reached 109.57 shoots/m2, at least in the control 97.81 shoots/m2 The highest yield in the Prunning reached 7.64 tons/ha, followed by the Prunning reached 6.82 tons/ha, lowest in the control reached 5.42 tons/ha Having such results, we think that the low main stem cutting stimulates the lower buds of undeveloped lower shoots to grow stronger and more, thus spreading wider leads to more buds and higher yields 3.2.3 Study on plucking techniques for two clones CNS-1.41, CNS-8.31 Plucking tea is picking the young part of shoots, breaking growth inhibition, facilitating the axillary sprout to develop into new buds and increase productivity However, the young and old degree of harvested shoots affects the yield and quality of tea Identified plucking techniques for two tea clones that were tested, the results are shown in Table 3.23 Table 3.23: Effects of plucking techniques on the growth of CNS - 1.41, of CNS - 8.31 at the age of 3, in Phú Thọ Clones Treatments Height Canopy Weight of Density of Yield of plucking (cm) width (cm) shoots shoots (tones/ha) (g/shoot) CNS – 1.41 CNS – 8.31 Plucking 74.58 a 180.00 Plucking 75.72a Plucking (shoots/m ) a 127.13a 12.30 a 176.44a 1.14a 119.48a 10.80 b 78.46a 178.37a 0.94b 123.35a 10.26b CV% 10.28 11.81 4.6 8.5 13.9 LSD0,05 7.70 9.30 0.16 a 153.5 a a 1.05 4.7 1.28 a 9.25a 1.14a 102.50a 8.28 b Plucking 68.74 Plucking 69.10a Plucking 70.47a 151.6 a 1.04a 104.79a 7.92b CV% 8.60 6.72 3.8 12.7 6.12 LSD0,05 5.0 8.60 0.2 6.4 0.90 147.7 a 1.15 a 101.30 Plucking 3: (Control For the CNS-1.41 clone, plant height in the plucking 1, plucking reached from 74.58-75.7cm, equivalent to plucking (control) reached 78.46cm; The canopy width in the treatments reaches from 180.0 to 76.44cm equivalent to plucking (control) reaching 178.37cm; The density of shoots reaches from 127.13 to 119.48 shoots/m2, which is equivalent to the plucking (control) reaching 132.35 shoots/m2 The highest yield in the plucking reached 12.30 tons/ha, followed by plucking with 10.80 tons/ha equivalent to plucking (control) reaching 10.26 tons/ha For the CNS - 8.31 clone, plant height in the treatments reaches from 68.74 cm to 69.10cm, equivalent to plucking (control) reached 70.47cm; The canopy width in plucking reaches 153.5 cm, plucking reached 147.7 cm is equivalent to plucking (control) reached 151.6 cm; The density of shoots/m2 in plucking reaches 101.30 shoots/m2, plucking 102.50 shoots/m2 is equivalent to plucking (control) 15 reached 104.79 shoots/m2; The highest yield of plucking reached 9.25 tons/ha, followed by the plucking yield of 8.28 tons/ha equivalent to plucking (control) reached 7.92 tons/ha Thus, for both tea clones, researching on the technique of plucking in treatment of plucking had the highest yield from 9,25-10,30 tons/ha 3.2.4 Study on fertilizer rates of N, P, K for two clones CNS - 1.41 and CNS - 8.31 Fertilizers play an important role in the life of tea plants, it provides the structure and development of tea leaves for harvest, so fertilizer is an important part of intensive production of tea plants Tea trees are often monoculture for a long period of time, inadequate fertilizer application, and the available nutrients in the soil will quickly be exhausted as regular tea collection deprives a large amount of soil nutrients , resulting in a deficiency of minerals in tea resulting in low productivity and degraded soil ecosystems Mineral fertilizer for tea reasonably is both a complete complement of nutrients to ensure good tea growth, high yield and significant health protection for tea land In order to find out the appropriate amount of mineral fertilizers to be applied to meet the nutritional requirements for the N, P, and K major elements of the two new tea clones, we investigated the fertilizer rates of N, P, and K with levels of fertilization different based on the standard 10TCN 446: 2001 Results are presented in Table 3.24 Table 3.24: Effects of fertilizer level on growth and yield of CNS-1.41, of CNS - 8.31 at the age of 3, in Phu Tho Clones Treatments Canopy Density of Weight of Yield Number of of fertilizer width shoots shoots (tones/ha) plucking levels Level (cm) (shoots/m ) a 171.8 116.34b (control) CNS – 1.41 (g/shoot) 1.09 a times (times) 9.68 c 17 Level 176.2a 125.30a 1.13a 11.34b - Level a 125.15 a 1.18 a b - 180.0 126.02 a 1.21 a a - CV (%) 8.3 6.2 10.2 6.0 LSD 0,05 29.3 7.4 0.2 1.4 146.7a 106.15c 0.98a 7.32c 17 147.5a 109.31bc 1.18a 7.86c 17 ab 1.19 a b 17 a 178.4 Level Level (control) Level CNS – 8.31 Level Level a 159.2 a 114.72 a 12.76 14.64 9.66 163.4 120.0 1.24 11.86 CV (%) 7.2 8.1 10.7 7.5 LSD 0,05 22.1 6.9 0.2 1.4 a 17 For the CNS-1.41, different fertilizer levels, the actual yield of the CNS-1.41 was different The fertilizing levels increased the amount of fertilizer N, P, K to 40%, the highest yield reached 14.64 tons/ha (up 51.23% compared to the control); For the CNS-8.31, the results were similar to those for the CNS-1.41 clone Actual yield in the experimental treatments of N, P, and K fertilizer rates was different at the 95% confidence level Accordingly, the highest yield in the fertilizing level increased by 40%, reaching 11.86 tons/ha (up 50.89% 16 compared to the control); In both tea clones, the highest yield in the amount of N, P, and K fertilizer increased by 40% (the CNS-141 reached 14.64 tons/ha, the CNS-831 reached 11.86 tons/ha) When increasing the amount of fertilizer N, P, K to 40% compared to the control, the tea yield continued to increase, we believe that it is due to the high growth and yield of CNS-1.41 and CNS-831 Both of clones should have high nutritional needs This may be the reason that the amount of mineral fertilizers is increased by 40%, the yield of two new tea clones continues to increase Applying a higher amount of N, P, and K fertilizers than the process would increase the cost of materials and labor, in order to clarify how the experimental results are economically effective, we calculated the he costs needed to produce tea shoots are shown in the following table 3.25 Table 3.25 Economic efficiency of the fertilizing levels on two tea clones CNS-141 and CNS-831 at the age of in Phu Ho, 2018 Calculating for 01 ha; Unit of calculation: VND 1,000 The CNS-1.41 No Content The CNS-8.31 Level Level Level Level (increased (control) (increased (control) by 40%) by 40%) A Total expenditure (A) =I+II 57,886 41,763 49,761 34,160 I Labors 48,838 34.253 40,753 26.690 Applying for fertilizer 3,019 2,160 3,019 2,160 Spraying for pests 3,240 3,240 3,240 3,240 Harvest 42,579 28,853 34,494 21,290 II Materials 9,008 7,470 9,008 7,470 Pestisides 3,640 3,640 3,640 3,640 Fertilizers 5,408 3,870 5,408 3,870 - N 2,440 1,750 2,440 1,750 - P2O5 1,120 800 1,120 800 - K2O 1,848 1,320 1,848 1,320 B Total revenue (B) 146,400 96,800 118,600 73,200 Tea fresh yields (kg) 14,640 9,680 11,860 7,320 C Profits (B-A) 88,514 55,037 68,839 39,040 Increase profits (%) 160.78 100 176.32 100 The data in the table comparing the cost of materials and labor of the two experimental treatments: i) the level applies the amount of fertilizer for 3-year-old tea according to 10CTN 446: 2001 and ii) the leve applies the amount of mineral fertilizer increase by 40% For the CNS-1.41 clone, the total cost per hectare of 3-year-old tea is 57,866,000 VND in level 4, higher than the total cost in level reaches 41,763,000 VND These costs include fertilizer, pesticides, and harvesting The total revenue from selling tea shoots in the level reached 146,400,000 VND compared to 96,800,000 VND in the level 1; profit of level reached VND 88,514,000, with 60.78% higher than that of control (profit of level reached VND 55,037,000) For CNS-8.31, the total cost in level is VND 49,761,000/ha, in level is VND 34,160,000; total 17 revenue from tea shoots in level is 118,600,000 VND/ha, in level is 73,200,000 VND/ha; profit of level reaches VND 68,839,000/ha, of level reaches VND 39,040,000/ha; profit in level is 76.32% higher than level Thus, increased 40% higher investment in fertilizer makes the cost of materials and labor increase, but the investment in fertilizer makes tea productivity increase and economic efficiency higher 3.2.5 Research on clonal propagation of two clones CNS-1.41, CNS -8.31 3.2.5.1 Results of cuttings rearing in mother gardens For tea plants, asexual propagation by cuttings plays an important role in production A tea variety with a high propagation coefficient and good clonal propagation ability will ensure the success of expansion in production The project has evaluated the cuttings productivity of two tea clones presented in Table 3.26 Table 3.26 Yield of cuttings of tea clones CNS-141 and CNS-831 at the age of 3, in Phu Ho Clones Branches for cuttings/branch cuttings Yield of cuttings (millions/ha) Rate of types of cuttings (%) Type A Type B CNS-1.41 28.26 a 7.80a 3.66a 67.8a 32.2b CNS-8.31 26.17 b 6.72b 2.92b 66.5b 33.5b LDP1(đ/c) 25.76 b 6.50b 2.78b 63.4c 36.6a CV (%) 3.44 9.70 7.70 8.40 10.70 LSD0.05 1.84 0.80 0.50 0.70 2.10 The results of table 3.26 showed that: after pruning, retain the branches that are qualified for cuttings, the number of cuttings carrying cuttings in the studied tea varieties is different The CNS-1.41 has 28.6 branches for cuttings per tree; CNS-8.31 and LDP1 had the same number of cuttings, reaching 26.17 and 25.76 branches for cuttings per tree Regarding the number of cuttings per branch, reflecting the cuttings productivity of the tea variety, the tea cuttings so that the variety has more cuttings, the cuttings productivity is high The CNS - 1.41 was 7.8 cuttings/branch, more than the CNS - 8.31 and the LDP1 (reached 7.72 and 6.5 cuttings/branch) The highest cuttings yield was the CNS - 1.41, which reached 3.66 million cuttings/ha; CNS - 8.31 and LDP1 control varieties have similar cuttings yield (2.92 and 2.78 million cuttings / ha) 3.2.5.2 Study the effect of cuttings of two tea clones To expand the area requires a large amount of seedlings by cuttings Therefore, we conducted a study to determine the ability of cuttings on two tea clones of CNS-1.41 and CNS-8.31 The research results obtained in Table 3.29 showed that: * For the CNS-141: It enjoyed the cuttings to the growth of the CNS-1.41 with a variable tree height (32.7cm) to (40.3cm), ordinary cuttings have the highest tree height (40.3cm) is equivalent to brown cuttings (control) (36.3 cm), the lowest is green cuttings (32.7 cm) equivalent to that of control brown cuttings The diameter of the trunk between the cuttings of the CNS - 1.41 varies (0.3 cm) to (0.4 cm), the dumpling cutting reaches (0.4 cm) higher than the brown cuttings (control) (0.3 cm), green cuttings (0.3 cm) are equivalent to control brown cuttings The rate of outplanting of the cuttings ranged from (78.5%) to (87.9%), of which the buds with the highest rate of outplanting reached (87.9%), followed by green cuttings (84.7%) had the same rate of outgardening as ordinary cuttings, the lowest is brown cuttings (78.5%) Thus, in buds, we can see that the body weight/root weight are larger than the control brown cuttings 18 for the plants to grow and develop well in the period of basic construction tea * For the CNS-831: The effect of cuttings on plant growth during the nursery stage of the CNS-8.31 strain had the highest tree height (40.2 cm), higher than the brown cuttings (control) (35, cm), the lowest is the green cuttings reached (31.7 cm) equivalent to the control brown cuttings The rate of gardening of the top-class cuttings reached 88.8%, the greening of 86.4% had the higher rate of gardening out of brown cuttings (80.4%) Thus, in buds, we can see that the body weight/root weight are larger than the control brown cuttings for the plants to grow and develop well in the period of basic construction tea Table 3.29 Growth of nursed tea plants from some cuttings of two tea clones in Phu Ho, 2018, after 10 months of incubation Clones/ cutivars Treatments Stump Height (cm) Number Body diameter of leaves weight weight body/root planting (g/tree) (g/tree) (cm) (ones) 13.2 6.9 2.2 4.7 84.7ab Ordinary cuttings 40.3a 0.4a 16.3a 10.3a 3.5a 6.8a 87.9a CNS – 1.41 Brown cuttings (c) 36.3ab 0.3b 14.5b 7.7b 2.5b 5.2b 78.5b CV% 5.4 5.8 4.7 9.2 6.2 4.8 7.3 LSD0,05 4.4 4.4 (E-02) 1.5 1.7 0.3 0.6 6.4 Green cuttings 31.7b 0.3 12.2b 6.0c 2.3c 3.7c 86.4a Ordinary cuttings 40.2a 0.4 14.2a 11.3a 5.0a 6.3a 88.8a Brown cuttings(c) 35.3b 0.3 13.0ab 7.9b 3.7b 4.3b 80.4b CV% 4.9 8.5 5.3 6.6 6.4 6.4 5.0 LSD0,05 3.9 6.4 (E-02) 1.6 0.7 0.5 0.2 3.9 a b a 80.5ab a b b b (%) 0.3 (control) b (%) 32.7 LDP1 b Rate of Rate of out Green cuttings CNS– 8.31 b Root Green cuttings b 25.5 0.3 12.8 6.7 1.9 4.5 Ordinary cuttings 27.3a 0.3 13.3a 6.8a 2.3a 4.8a 82.5a Brown cuttings (c) 24,5b 0.3 11.1b 5.6b 1.8b 3.8b 76.3b CV% 5.6 11.7 4.5 6.1 8.2 5.1 7.1 LSD0,05 1.2 7.9 (E-02) 1.2 0.4 0.3 0.3 5.7 (c): control 3.2.5.3 Research results on cuttings seasoning of two experimental tea clones Tea cuttings depend on many factors such as: temperature, humidity, light in the garden of cuttings Each season will correspond to different conditions, the results are in Table 3.30 * CNS - 1.41 clone: The data of Table 3.30 showed that: height of the CNS - 1.41 cuttings in August - September has the largest tree height of 40.3 cm, followed by October - November with (36.5 cm), with dimension equivalent tree height in June - July (32.6 cm) has a higher than the December - January season (control) (27.3 cm) The diameter of stem in cuttings during August - September and November - November reaches (0.4 cm), followed by June - July cuttings (0.3 cm) higher than that was in December - January (control) has the smallest original diameter of only (0.2 cm) Regarding the number of leaves in trees of June - July, August - September and October - November 19 seasons, the number of leaves on trees is equivalent (14.2 - 16.3), December - January (control) has a low number of leaves/plant compared to the months statistically achieved (11.2 leaves) The rate of outgrowth between August - September (98.9%), October - November (97.3%), June - July (90.6%) has the same rate of outgrowth December - January (control) reached 76.5% statistically significant difference * CNS - 8.31 clone: Regarding the height of trees in August - September, the largest is 40.3 cm, October - November reaches (35.7 cm), equivalent to June - July (31.6 cm), cuttings in December - January (control) (27.0 cm) Stem diameter in August - September and October - November reached (0.3 cm), followed by June July (0.2 cm) higher than that was in December - January (control) reached (0.2 cm) About the number of leaves on trees 8-9 and October - November are equivalent (reaching 13.5 to 14.7 leaves) The rate of outgrowth between August - September (99.6%), October - November (94.5%), June July (91.3%) has the same rate of outgrowth than December - January (control) reached 73.4% statistically significant difference For LDP1 tea varieties (control) different cuttings season, the growth and development of different cuttings, similar to the state of the two tea clones investigating cuttings season, ie cuttings in months 8-9 young seedlings grow stronger than other season, the highest rate of outplanting reached 88.3% Table 3.30 Some growth indicators of two tea cloner CNS - 1.41, CNS - 8.31 for season cuttings in Phu Ho, Phu Tho (After 10 months of cutting) Clones/ Seasonal Height Stump N of Body cutivars cuttings (cm) diameter leaves weight weight body/root planting (cm) (ones) (g/tree) (g/tree) (time) CNS – 1.41 CNS – 8.31 LDP1 (đ/c) Jun – Jul 32.6 0.3 Aug – Sep 40.3a Oct –Nov b b a b Root b Rate of Rate of out (%) (%) 4.8 b 90.6 a 14.2 6.9 2.2 0.4a 16.3a 10.3a 3.5a 6.8a 98.9 a 36.5ab 0.4a 15.5a 7.7b 2.4b 5.3ab 97.3a Dec – Jan (c) 27.3c 0.2c 11.2b 6.3b 2.1b 5.1b 76.5 b CV% 6.3 3.9 10.9 3.9 10.3 15.4 7.8 LSD0,05 4.3 0.02 2.9 0.6 0.5 1.6 13.4 c c 3.9 b 91.3 a Jun – Jul 31.6 ab 0.2 12.8 Aug – Sep 40.3a 0.3 14.7a 11.4a 5.0a 6.4a 99.6 a Oct –Nov 35.7ab 0.3 13.5ab 8.0b 3.7b 4.3b 94.5 a Dec – Jan (c) 27.0b 0.2 11.2c 6.4bc 1.4d 5.0ab 73.4 b CV% 14.8 16.3 5.2 10.9 6.1 15.2 8.5 LSD0,05 9.4 1.6 0.3 1.4 14.3 b b 4.1 b 79.5 b 0.07 Jun – Jul 30/8 0.2 Aug – Sep 35.4a 0.3a Oct –Nov 32.6ab Dec – Jan (c) bc b b 1.3 11.5 b 6.1 2.2 5.9 2.2 12.3ab 9.7a 3.5a 6.2a 88.3a 0.3a 12.5a 6.6b 3.3a 4.5b 83.3ab 28.3c 0.2b 10.3c 5.3b 1.3c 3.3b 69.5 c CV% 6.5 15.6 3.7 13.3 14.93 15.1 3.2 LSD0,05 4.1 0.08 0.8 1.7 0.8 1.2 5.2 20 (c): control Conclution, when studying the cuttings season for new tea clones CNS-1.41 and CNS-8.31 have determined that cuttings in the August-September season, young tea plants grow strongly, the rate of outplanting reaches 98.9 to 99.6%, both are higher than the variety LDP1 (88.3%) in which the rate of outplanting of the CNS - 8.31 is higher than that of the CNS - 1.41 3.2.6 Testing two new tea clones Two new tea clones CNS-1.41 and CNS-8.31 grow well, have high productivity, so that they can soon develop into production, and at the same time studying agronomic characteristics, we have conducted a large-scale field trial in production conditions in some northern mountainous regions Including Phu Tho, Tuyen Quang and Yen Bai, planting time in January 2015, the control variety was LDP1 The trial tea gardens conducted the first prunning in December 2015, assessing productivity from the age of (2016) to November 2019 Results of tea yield evaluation at trial sites are presented in tables 3.31, 3.32 and 3.33 Table 3.31: Elements of productivity and yield changes in the years 2016-2019 for two new tea clones in Phu Ho and Phu Tho Clones/ Density of Weight of Canopy cutivars shoots three leave width 2016 2017 2018 and bud (cm) (age 2) (age 3) (tuổi 4) (tuổi 5) a 7.93 a 12.57 7.76 a b 14.53 c 9.43 b 6.19 6.6 (shoots/m ) Yield changes in the years (tones/ha) 2019 Average of years compared (g/shoot) CNS– 1.41 CNS– 8.31 LDP1 a 186.60 a 176.40 b a 1.21 a 1.29 b Increase to control a 182.0 ab 168.7 b 4.62 a 4.57 3.91 b 4.89 b 10.2 6.56 a a 10.68 a a 149.59 b 100 17.63 150.15 1.06 163.2 CV% 5.3 13.7 4.7 6.3 9.2 4.0 14.7 LSD0,05 20.7 0.14 18.3 0.6 1.5 0.8 4.5 a 9.26 172.54 (control) 1.3 The data table showed that the CNS - 1.41 has a shoot density of 186.60 shoots/m with a density of shoots equivalent to the CNS - 8.31 with a shoot density of 176.5 shoots/m2 , the control variety LDP1 has a density of shoots with 150.15 shoots/m2 The weight of three leaves and bud of the two clones CNS - 1.41 and CNS - 8.31 from 1.21g to 1.29g/shoot were similar and bigger than shoot weight of LDP1 tea variety (1.06 g/shoot) The largest canopy width is CNS – 1.41 reaching 182 cm (level a), followed by CNS - 8.31 with canopy width of 168.7 cm (ab level), the smallest canopy width is LDP1 reaching 163, cm (level b) In terms of yield, after years of evaluation, CNS - 1.41 and CNS - 8.31 clones were early yielded high, even at the age of 2, shoots collected 4.62 and 4.57 tons/ha higher than the control varieties (LDP1 reached 3.91 tons/ha) In the third year of entering the business period, the CNS - 1.41 and CNS - 8.31 had high yields of 7.93 and 7.76 tons/ha, higher than the control varieties at 4.89 tons/ha In the 4th year, the yield/clones continued to increase and there was a difference, the CNS - 1.41 had the highest yield of 12.57 tons/ha, followed by the CNS - 8.31 clone with 10.2 tons/ha, the lowest yield of LDP1 is 6.56 tons/ha In the fifth year, the yield of CNS - 1.41 tea was 17.63 tons/ha, equivalent to the yield of CNS - 8.31 clones of 14.53 tons/ha, and higher than that of LDP1 with 9.43 tons/ha 21 The average yield of years of the CNS - 1.41 had the highest yield of 10.68 tons/ha and the CNS 8.31 was 9.26 tons/ha, higher than the control LDP1 of 6.19 tons/ha The yield of CNS - 1.41 was higher than the control of 72.54%, the yield of CNS - 8.31 was higher than the control variety 49.53% Table 3.32: Components of productivity and yield changes in the years 2016-2019 for two new tea clones in Yen Son and Tuyen Quang Clones/ Density of Weight of Canopy cutivars shoots three leave width and bud (cm) (shoots/m ) Yield changes in the years (tones/ha) 2016 2017 2018 2019 (age 2) (age 3) (tuổi 4) (tuổi 5) (g/shoot) CNS– 1.41 CNS– 8.31 LDP1 a 181.60 a 173.40 b a 1.11 a 1.09 b a 182.6 165.4 b b a 4.71 a 4.25 3.78 b a 12.26 a a 14.13 b b 7.98 7.26 154.15 0.93 163.8 4.82 CV% 3.1 4.3 3.5 5.7 7.9 LSD0,05 12.2 0.1 13.7 0.6 1.3 b a 9.64 6.62 a 16.53 a Average Increase of compared years to control 10.37a 168.89 8.82 b 143.65 c 100 9.34 6.14 4.7 9.8 66 0.9 3.0 0.7 (control) In Tuyen Quang, the clones/cutivars for research and development are quite well developed The CNS - 1.41 and the CNS-8.31 had the same shoot density of 181.60 and 173.4 shoots/m2 and were higher than the shoot density of the LDP1 (control) with the density of 154.15 shoots/m2 The weight of three leaves and buds of the two clones CNS - 1.41 and CNS - 8.31 (from 1.09 to 1.11 g/shoot) is larger than the weight of shoot of LDP1 (0.93 g/shoot) The largest canopy width is the CNS-1.41 line reaching 1.12 m2, the CNS8.31 and the LDP1 variety have the same canopy width, reaching 165.4 and 163.8 cm In terms of yield, similar to that in Phu Tho, the tea clones/cultivars grew well, the second year after planting, the harvest was quite high The two clones CNS-1.41 and CNS-8.31 were similar in productivity, reaching 4.71 and 4.25 tons/ha, higher than the control LDP1 at 3.98 tons/ha In the following years, the yield of tea clones/cutivars continued to increase with age of tea, the average yield of years assessed (from 2016 to 2019) of tea varieties was different at the 95% confidence level Accordingly, the CNS-1.41 had the highest yield, reaching 10.37 tons/ha, followed by the CNS-8.31 with 8.82 tons/ha, the lowest of the LDP1 was 6.8 tons/ha The CNS - 1.41 and CNS - 8.31 were higher than the LDP1 by 68.89% and 43.65%, respectively Thus, in Tuyen Quang, two new tea clones are completely suitable to climatic conditions, soil and showed that they were strong growth characteristics, high productivity, and can widely develop in the region In Yen Bai: The results in the table showed that the tea clones grow well in Van Chan and Yen Bai Accordingly, growth indicators such as canopy width, shoot density and weight are similar to those in Phu Tho and Tuyen Quang The CNS-141 has a canopy width of 180 cm, higher than the canopy width of CNS8.31 and LDP1 (which reachs 167.2 and 161.3cm) The weight of three leaves and bud of the CNS - 1.41 had the largest weight of 1.32 g/shoot, followed by the CNS - 8.31 with 1.12 g/shoot with a bigger weight than the LDP1 variety (0.98 g/shoot) In terms of shoot density, the CNS-1.41 reached the highest of 161.60 shoots/m2, the CNS-8.31 and the LDP1 variety had similar shoot density, reaching 143,40 shoots /m2 and 134,15 shoots /m2 respectively 22 Table 3.33: Factors of productivity and yield changes in the years 2016-2019 for two new tea clones in Van Chan and Yen Bai Clones/ Density of Weight Canopy cutivars shoots (3 leaves width 2016 2017 & a bud (cm) (age 2) (age 3) (shoots/m ) Yield changes in the years (tones/ha) 2018 2019 (tuổi 4) (tuổi 5) Average of years compared (g/shoot) CNS– 1.41 CNS– 8.31 LDP1 a 161.60 b 143.40 b a 1.32 to control a 180.0 b 4.51 a 4.24 a b 167.2 c b 3.58 1.12 Increase 161.3 b 7.78 a 11.66 7.36 a b 4.64 b a 9.02 6.82 c a 10.00 166.11 ab b 140.86 c 100 16.07 13.33 9.04 a 8.48 b 6.02 134.15 0.98 CV% 5.03 5.7 3.2 3.2 3.5 4.2 13.8 5.5 LSD0,05 16.7 0.1 12.4 0.3 0.5 0.9 4.4 0.9 Regarding yield, in the second year after planting, the CNS - 1.41 reached 4.51 tons/ha, the CNS 8.31 reached 4.24 tons/ha, higher than the yield of the LDP1 of 3.58 tons/ha In the following years, tea productivity continued to increase, the average yield of the four years assessed (2016-2019) varied at a 95% confidence level The CNS-1.4 had the highest average yield of 10.0 tons/ha, followed by the CNS-8.31 with 8.48 tons/ha, the lowest of the LDP1 was 6.02 tons/ha In Yen Bai, the yield of CNS-1.41 was 66.11% higher than that of LDP1, and CNS-8.31 was 40.86% higher than LDP1 Thus, through the assessment of the growth and yield of two new tea clones CNS-1.41 and CNS8.31 in the experimental areas of Phu Tho, Tuyen Quang and Yen Bai, the new clones have promoted the growth characteristics very well Easy to plant, early for harvest, the second year can be put into production and business, stable productivity is always higher than the control cutivar, they has been popularly grown in the trial areas The test results confirmed that the two new tea clones CNS-1.41 and CNS-8.31 are suitable for the ecological conditions in the test areas, which can be widely developed in these and surrounding areas CONCLUSION AND RECOMMENDATIONS 1.Conclusion 1.1 Morphological characteristics of leaves, shoots and cuttings of two new tea clones: - The CNS-1.41 tea clone has yellow green leaves, 13.7 cm long, 5.9 cm wide, the leaf area is 57.6 cm , the surface of the leaves is rough, the leaves are pointed, the leaves are outward; three leaves and bud is 9,58 cm long, yellow green, 1.2 g weight; internode is 4.79 cm long, about 4.33 mm diameter, the area of the leaves of cuttings is 57.56 cm2 - The CNS-8.31 tea clone has dark green leaves, 10.8 cm long and 4.6 cm wide, the leaf area is 34.9 cm , the surface of the leaves is rough, the leaves are pointed and the leaves are pointed upwards; three leaves and bud is 8.71 cm long, 1.16 g weight; internode is 5.15 cm long, about 4.52 mm diameter, the area of the leaves of cuttings is 34.87 cm2 1.2 Characteristics of growing two new tea clones: - CNS-1.41 one-year-old tea trees have a stem height of 120.4 cm, a stem diameter of 1.3 cm, a low branch height of 2.0 cm, a number of branches of primary and secondary branches reaching 25.7 and 39 branches/tree; The CNS-8.31 trees have a trunk height of 128.4 cm, a stump diameter of 1.3 cm, an average branch height of 3.6 cm, a number of first and second level branches of 15.9 and 23.6 branchs/tree Two 23 clones CNS-1.41 and CNS-8.31, one year after planting, have met the size requirements for prunning for the first time - In the second year, two tea clones grow well and have been harvested, the CNS-1.41 has a canopy wide of 120.7 cm, a shoot density of 121.5 shoots/m2, yield reaches 7.36 tons/ha; the CNS-8.31 has a canopy wide of 93.6 cm, a shoot density of 92.5 shoots/m2, yield of 5.22 tons/ha - The 3-year-old CNS-1.41 tea trees have a canopy wide of 180.4 cm, a yield of 13.68 tons/ha; the CNS-8.31 trees have a canopy wide of 167.6 cm, yield of 9.72 tons/ha; The potential yield (theoretical yield) of CNS-1.41 reaches 19.42 tons/ha, the CNS-8.31 reaches 17.01 tons/ha - Quality of tea raw materials: shoots of the two leaves and bud have a percentage of stalks and a average fiber ratio of the seasons is low The CNS-1.41 has a ratio stalk/shoot of 21.66%, a fiber percentage of 17.86%; the CNS-8.31 has a ratio stalk/shoot of 25.82%, and a fiber ratio of 16.07% - Composition of major compounds in two new tea clones suitable for processing green tea of good quality, low tannin content, catechin and amino acids are quite high: The CNS-1.41 has a tannin content of 51%, soluble matter of 42.43%, a total amino acid of 2.45%, a vitamin C of 16.72 mg/kg dry matter, a total polyphenols of 17.98%; CNS-8.31 has a tannin content of 24.47%, a soluble matter of 43.28%, a total amino acids of 2.56%, a vitamin C of 22.04 mg/kg dry matter, a total polyphenols of 20.14% - The composition of major compounds in black tea of the two new tea clones is also suitable for processing high quality black tea: The black tea product of the CNS-1.41 has a tannin content of 14.35%, a soluble matter of 37.55%, a catechin 74.05%; black tea products of the CNS-8.31 has a tannin content of 14.08%, a soluble matter of 36.27%, a catechin of 72.96%; - Sensory quality of green tea: The CNS-1.41 has a small curly appearance, yellowish green water, light fragrance, mild bitter taste, total evaluation score of 16.43 points, a good quality rating; The CNS-8.31 has a small dark green curly wing, bright blue water, a characteristic aroma, a mild and sweet flavor, a total of 17.94 points, a fair quality rating - Sensory quality of black tea: The CNS-1.41 series has dark brown wings, bright red water, typical aroma, sweet tannue, a total score of 17.5 points, good quality classification; The CNS-8.31 has a dark brown appearance, a bright red water, a specific aroma, a mild bitter taste, a total score of 18.6 phoints, which ranks good quality black tea 1.3 Regarding technical measures: - Planting two new tea clones have a density of 16.6 thousand trees/ha and 18.5 thousand trees/ha under the method of early double-canopy, high shoot density and higher yield than planting the same density by row method single: the CNS-1.41 were planted a density of 16.6 thousand trees/ha and a double row, yield at the age of reached 17.15 tons/ha, but planting of single row reaches yield of 13.15 tons/ha; the CNS-8.31 were planted a double rows, yield reaches 14.85 tons/ha, and single row reaches 13.33 tons/ha - First shaping prunning with main stem at a height of 15-20 cm, a lateral branch height of 35 cm suitable for two new tea clones - Plucking at the height of the 10 cm has a high yield, the CNS-1.41 and the CNS-8.31 have a canopy wide of 153.5 - 180.00 cm, a shoot density of 101.30 - 127, 13 shoots/m2; productivity reaches from 9.25 to 12.3 tons/ha - Fertilizing for the age of trees by the treatment level (112 kg N + 56 kg P2O5 + 84 kg K2O / ha), the yield of the CNS-1.41 reached 14.64 tons/ha, the CNS-8.31 reaches 11.86 tons/ha; increased 24 fertilizer volume to 40% to achieve high economic efficiency, profit increased 60.78% for the CNS-1.41 clone, up 76.32% for the CNS-8.31 clone 1.4 Clonal propagation ability of the two clone studied tea strains: - Yield of mother garden cuttings of age reaches 3.66 million cuttings/ha with the CNS-141 clone, reaches 2.92 million cuttings with the CNS-831 clone - Percentage of outnursery after 10 months reaches 87.9% for CNS-141 and 88.8% for CNS-831 1.5 Growth and productivity of two new tea lines in the trial areas - In Phu Tho: the CNS-141 clone has an average yield of years reaching 10.68 tons/ha, an increase of 72.54% compared to the control variety; CNS-831 clone has an average yield of 9.26 tons/ha, an increase of 49.59% compared to the control - In Tuyen Quang: CNS-141 clone has an average yield of years reaching 10.37 tons/ha, up 68.89% compared to the control variety; CNS-831 clone has an average yield of 8.82 tons/ha, up 43.65% compared to the control - In Yen Bai: CNS-141 clone has an average yield of years was 10.0 tons/ha, increasing by 66.11% compared to the control variety; CNS-831 clone has an average yield of 8.48 tons/ha, an increase of 40.86% compared to the control - The two new tea clones are completely suitable and can be widely developed in the testing areas and the surrounding areas 2.Recommendation Currently, two clones of tea CNS-1.41 and CNS-8.31 have been recognized as new varieties named CNS 141 and CNS 831, which were allowed for trial production by the Ministry of Agriculture and Rural Development in the Northern Uplands Based on the research results, we have the following suggestions: - Researching to improve techniques of planting and tending two new tea varieties CNS 141 and CNS 831; further evaluation of the double planting method that can take advantage of the strong and concentrated growth of tea shoots in the middle of the tea canopy to increase productivity and facilitate mechanical harvesting; assessing the optimal amount of mineral fertilizer to promote the potential of yielding two new tea varieties and to protect and enhance the fertility of tea-growing soil; - Studying techniques of processing black tea green tea in accordance with raw materials of two new tea varieties CNS 141 and CNS 831, diversifying tea products; - To develop the production of two new tea varieties in regions similar to the testing areas, further assess in other tea regions, contributing to raising the yield and quality of our country LIST OF SCIENTIFIC PUBLICATIONS RELATED TO THE THESIS Trinh Thi Kim My, Nguyen Huu La, Nguyen Van Thiep (2016), Researching some growth and development characteristics of two newly selected tea varieties CNS - 1.41 and CNS - 8.31 in the basic construction period in Phu Ho and Phu Tho Journal of Agriculture and Rural Development - December 2016, pages 174-179 Trinh Thi Kim My, Nguyen Van Thiep and Le Van Duc (2019), The influence of some main cultivation techniques on the growth of two new tea lines CNS - 1.41 and CNS - 8.31 in Phu Tho Vietnam Journal of Agricultural Science and Technology 26 - Issue - 2019 Trinh Thi Kim My, Nguyen Van Thiep and Nguyen Huu La (2019), The ability to supply cuttings of two varieties of tea CNS - 1.41 and CNS - 8.31 in Phu Ho, Phu Tho Journal of Agriculture and Rural Development No 20 - October 2019 ... (times) a a a a 13 0.6 1. 05 b 17 19 .42a CNS- 1. 41 76.6 1. 81 1.50 CNS- 8. 31 78. 2a 1. 62b 1. 32 b 11 2.8b 1. 21a 17 17 .01b LDP1(control) 75.6a 1. 51b 1. 21 b 10 2.8b 0.93c 17 10 .92c CV% 3.60 3.90 4 .82 7.20 5.20... 0.2 1. 4 14 6.7a 10 6 .15 c 0.98a 7.32c 17 14 7.5a 10 9.31bc 1. 18a 7 .86 c 17 ab 1. 19 a b 17 a 17 8. 4 Level Level (control) Level CNS – 8. 31 Level Level a 15 9.2 a 11 4.72 a 12 .76 14 .64 9.66 16 3.4 12 0.0 1. 24... (g/shoot) CNS 1. 41 CNS 8. 31 LDP1 a 18 6.60 a 17 6.40 b a 1. 21 a 1. 29 b Increase to control a 18 2.0 ab 16 8. 7 b 4.62 a 4.57 3. 91 b 4 .89 b 10 .2 6.56 a a 10 . 68 a a 14 9.59 b 10 0 17 .63 15 0 .15 1. 06 16 3.2