Nghiên cứu đặc điểm nông sinh học và áp dụng một số biện pháp kỹ thuật nâng cao năng suất chất lượng bưởi xuân vân, tỉnh tuyên quang tt tiếng anh

THAI NGUYEN UNIVERSITY THAI NGUYEN UNIVERSITY OF AGRICULTURE AND FORESTRY VI XUAN HOC STUDY ON AGRO - BIOLOGICAL CHARACTERSTICS AND APLICATION OF TECHNICAL MEASURES TO IMPROVE YIELD AND QUALITY OF XUAN VAN POMELO IN TUYEN QUANG PROVICE Major: Crop science Code: 9620110 PHD THESIS SUMMARY IN CROP SCIENCE THAI NGUYEN - 2020 This study was completed at: THAI NGUYEN UNIVERSITY OF AGRICULTURE AND FORESTRY Supervisors: Assoc Pro Dr Nguyen Quoc Hung Dr Nguyen Van Vuong Examiner 1: Examiner 2: Examiner 3: The thesis will be defending before the board of grassroots level Meeting at: Thai Nguyen University of Agriculture and Forestry - Thai Nguyen University At hours days month 2020 Refer at: - National Library - Learning Resource Center - Thai Nguyen University - Library of Thai Nguyen University of agriculture and Forestry PUBLICATIONS INCLUDED IN THIS THESIS Vi Xuan Hoc, Nguyen Quoc Hung, Nguyen Van Vuong, Tran Thi Nhung (2017) “Results of the study on growth characteristic, flowering, and fruit setting physiology of xuan Van pummelo cultivar grown in Tuyen Quang province”, Journal of Agriculture and Rural Development thematic livestock breeds episode pp.97-102 Vi Xuan Hoc, Nguyen Quoc Hung, Nguyen Van Vuong, Hoang Thi Thu Hoan (2018) “Study on effects of the growth regulator Ga3 to fruit setting, yield and quality of Xuan Van pummelo in Tuyen Quang province”, Journal of Agriculture and Rural Development, No 15/2018, pp 31 - 36 Vi Xuan Hoc, Nguyen Quoc Hung, Nguyen Van Vuong, Nguyen Thi Hai (2019) “Influence of additional pollination on fruit setting, yield and quality of Xuan Van pummelo in Tuyen Quang province.”,Journal of Agriculture and Rural Development, No 3+4, 3/2019, pp 38 - 42 OPENING The urgency of the thesis Grapefruit (Citrus Grandis (L.) Osbeck) is a nutritious fruit tree, widely grown in Vietnam, each region has a number of different grapefruit varieties as a result of selection and influence of different ecological conditions which have established famous pomelo growing areas such as: Doan Hung Pomelo (Phu Tho); Dien Pomelo (Ha Noi); Dai Minh pomelo (Yen Bai); Phuc Trach pomelo (Ha Tinh); Da Xanh pomelo (Ben Tre), Nam Roi Pomelo (Vinh Long) etc Grapefruit is one of the agricultural crops that bring high economic efficiency, long storage time, less putrescent during transportation, easy to cultivate, especially grapefruit trees are resistant to some dangerous diseases on citrus Tuyen Quang is a northern midland and mountainous province with suitable ecological conditions for growth with fruit trees, including citrus and grapefruit Currently Tuyen Quang province is focusing on developing and expanding the area of Xuan Van grapefruit because the grapefruit has the advantages of early harvesting and the ability to spread crops However, the production of Xuan Van grapefruit is still spontaneous now, there are no scientific arguments based on the weather conditions of Tuyen Quang province, which will lead to many risks for production Therefore, the thesis "Research on agrobiological characteristics and some technical measures to improve productivity and quality of Xuan Van pomelo in Tuyen Quang province" is very necessary Research objectives of the thesis Based on the study of origin, agro-biological characteristics determining the law of growth and development of Xuan Van grapefruit in the ecological and climatic conditions of Tuyen Quang province, which serves as a scientific basis for the application of measures, technical and formulating technical process of cultivating Xuan Van grapefruit variety in Tuyen Quang province to achieve high quality productivity, contributing to improving economic efficiency and increasing income for people Scientific and practical significance of the thesis 3.1 Scientific significance - Identifying the differences between Xuan Van grapefruit and other grapefruit varieties originating from Tuyen Quang; identifying the rules of growth, development of flowering and fruiting as a scientific basis for the development and application of farming techniques to improve the productivity, quality and efficiency of growing pomelos - The results of applying technical measures to Xuan Van pomelos not only help to increase productivity, quality, but also contribute to the construction of Xuan Van pomelo intensive farming technique - The scientific significance of the thesis is the first scientific research which studies systematically about the new variety of Xuan Van grapefruit, and it is a valuable reference in research and teaching 3.2 Practical significance - The results of research on technical measures applied in producing Xuan Van pomelo will contribute to improving quality productivity and high economic efficiency for producers - The research results are also a scientific basis for the planning of citrus production in general and pomelos in particular, which are more effective in the ecological conditions of Tuyen Quang province Research subject and scope 4.1 Research subjects Xuan Van pomelo variety is grown in Xuan Van commune, Yen Son district, Tuyen Quang province 4.2 Research scope The project was implemented from 2014 to 2018 in Xuan Van commune with the main contents: studying morphological characteristics, studying agro - biological characteristics and some technical measures to improve productivity, quality of Xuan Van pomelo in Tuyen Quang province The novelty of the thesis - Determine the laws of growth, development, flowering, fruiting, identify the relationships among branches in the year, these are the agronomic characteristics that are the basis for the application of technical measures for Xuan Van grapefruit - Identify some technical measures such as fertilizing, pruning, additional pollination, using GA3 growth regulator, post-harvest preservation, this is a very important scientific basis for construction of technical process of intensive farming of Xuan Van pomelo in Tuyen Quang province The arrangement of the thesis The main thesis has 135 pages of A4 - size with 49 tables of figures and 114 references structured as follows: Commitment, acknowledgment, table of contents, list of symbols and abbreviations, list of tables, list of figures, introduction (4 pages) Chapter 1: Overview of research documents (46 pages) Chapter 2: Content and research methodology (16 pages) Chapter 3: Research results and discussion (67 pages) Conclusions and recommendations (2 pages) and references (12 pages including 63 Vietnamese documents, 51 English documents) In addition, the thesis also has an appendix containing data, processing data and some images related to research experiments Chapter OVERVIEW OF RESEARCH DOCUMENTS The thesis has consulted and reviewed 63 Vietnamese documents and 51 English documents including; Origin and classification of citrus trees; Situation of production and consumption of pomelos in the world and in Vietnam; Some agronomic characteristics of citrus; Factors affecting the development of citrus; Researches on technical measures to increase the productivity and quality of pomeloes With the data collected show: In the world, there have been many researches on the origin of citrus classification, grapefruit originated from Asia but now it has developed in many countries around the world Grapefruit has high nutritional value and high economic value In the world and Vietnam, there are many famous grapefruit varieties with high economic efficiency, such as Xuan Van grapefruit The study of agro - biological characteristics and the study of some technical measures for grapefruit is an urgent topic for production Many researches have been conducted in the world and Vietnam on the effectiveness of a number of technical measures affecting the flowering, fruiting, productivity and quality of citrus in general, and grapefruit trees in particular, such as pruning, zoning, fertilizing, using growth regulators, supplementing pollination, preserving after harvesting, etc These are necessary technical measures for citrus in general and pomelos in particular These are technical measures to increase the ability of flowering, fruiting, and increasing the productivity and quality of citrus and grapefruit trees in the direction of benefit to humans However, the grapefruit researches on the impact of technical measures to regulate fruiting, flowering, productivity, quality and preservation which are still limited Xuan Van grapefruit originated in Xuan Van commune, Yen Son district, Tuyen Quang province, currently researches on this grapefruit have not been mentioned The research content of the thesis studies agro-biological characteristics as a basis for proposing the construction of Xuan Van grapefruit cultivation process in Tuyen Quang province The technical measures that need to be studied are: Identify optimal measures for pruning, timing of zoning, fertilization, growth control, additional pollination and post - harvest preservation for Xuan Van pomelo variety in Tuyen Quang province Chapter SUBJECTS, CONTENTS AND RESEARCH METHODOLOGY 2.1 Subjects, times, locations and research materials 2.1.1 Subject of the research Research subjects: Xuan Van pomelo variety 2.1.2 Time and locations of research - Research period from 2014 to 2018 - Research location: Xuan Van commune, Yen Son district, Tuyen Quang province, Institute of life sciences at Thai Nguyen University 2.2 Research materials - Inorganic fertilizer: Ha Bac nitrogenous fertilizer (N 46%), Van Dien phosphate fertilizer (P2O5 17%), Potassium chloride fertilizer (K2O 60%), NPK fertilizer Lam Thao, NPK ratio 5: 10: - GA3 growth regulator: 50 ppm, 60 ppm, 70 ppm, 80 ppm, 90 ppm - Pastel sources: Sour grapefruit, Dien grapefruit, Cat Que grapefruit and Xuan Van grapefruit - Preservative material: Smart film preservatives Polyethylene wax (12% dry matter), Carnauba wax (6% dry matter), red ant resin (2% dry matter), Chitosan (concentration 1.5% ), dry sand 2.3 research content 2.3.1 Content 1: Studying agro-biological characteristics of Xuan Van pomelo variety 2.3.2 Content 2: Studying influencing a number of technical measures to productivity and quality of Xuan Van grapefruit 2.3.3 Content 3: Building intensive farming model of Xuan Van pomelo 2.4 Research Methods 2.4.1 Research methods on some agro-biological characteristics 2.4.1.1 Research methods on morphological characteristics of stem, leaf, flower and fruit characteristics - Studying morphological characteristics of stems and branches, at the age of tracking 10 trees without repeating - Studying the leaf morphological characteristics: each tree tracks ages, each tree has 10 leaves - Studying Flower case: track 10 plants at the age of years, the number of monitoring 10 trees 30 flowers / tree - Research on fruit characteristics: Track five fortune-telling trees and stable-yielding annual trees each age tracks trees, each tree tracks 10 fruits 2.4.1.2 Studying characteristics of growth and development of pomelos of Xuan Van grapefruit - Studying growth characteristics over years old compared with Dien grapefruit according to over ages, each age monitored 10 trees without repeating - Studying the origin of buds, tracking 10 trees without repeating - Studying the distribution of flower sprouts, tracking 10 trees without repeating - The study determined the time of flowering, followed by 10 trees without repeating - Studying flower drop, physiological fruit drop, tracking trees without repeating - The study determined the ripening period and harvest time, monitored 10 trees without repeating and compared with Dien grapefruit at the same age 2.4.2 The research method influences a number of technical measures on the productivity and quality of Xuan Van grapefruit Methods of experiment arrangement: The field experiments from experiment to experiment were arranged in a completely randomized manner (RBCD) on pomelo gardens of - 10 years old, repeats, each formula on trees 2.4.2.1 Experiment 1: Studying the effect of pruning techniques on the growth, development and productivity of Xuan Van grapefruit - The experiment consists of formulas + Formula (control): No pruning + Formula 2: Pruning according to the process of the Vegetable Research Institute + Formula 3: Cut according to the type of initiation - Pruning technique: + Formula 1: Control to natural without pruning + Formula 2: Pruning according to the process of the Vegetable and Fruit Research Institute which is trimmed into times: first pruning in Spring crop, 2nd time in Summer crop, 3rd time in Autumn crop, pruning after harvest fruit + Formula 3: Cutting according to initiation (Open heart) pruning the first and second level branches growing in the middle of the canopy, leaving only 3-5 main branches (frame branches) Pruning elevation branches regularly, pest branches located inside the canopy with a diameter of less than 0.2 cm - In addition to the experimental factors, the formulas were cared for a common platform: 50 kg of decomposed animal manure + 800 gram of nitrogen + 400 gram of P2O5 + 600 gram of K20 + kg of lime/tree, Inorganic fertilizers are divided into times: fertilizing the first time to flower, the second fertilizing the fruit, the 3rd fertilizing fruits and ending the autumn branches, the fourth fertilizing after harvest Pest and disease control follows a common procedure 2.4.2.2 Experiment 2: Studying the effect of chipping time on the productivity and quality of Xuan Van grapefruit - The experiment includes formulas + Formula 1: Highlight the second grade on December + Formula 2: Highlight the second grade on December 15 + Formula 3: Highlight the second grade on December 25 + Formula 4: Control without freezing - Use a specialized knife to circle a branch The width of the circle is mm, the depth is just enough to reach the cambium - In addition to the experimental factors, the formulas were cared for a common platform: 50 kg of decomposed animal manure + 800 gram of nitrogen + 400 gram of P2O5 + 600 gram of K20 + kg of lime / tree, Inorganic fertilizers are divided into times: fertilizing the first time to flower, the second fertilizing the fruit, the 3rd fertilizing fruits and ending the autumn branches, the fourth fertilizing after harvest Pest and disease control follow a common procedure 2.4.2.3 Experiment 3: Studying the effect of fertilizer formulas on productivity and quality of Xuan Van grapefruit - The experiment includes formulas + Formula 1: NPK ratio 1: 1: (400: 400: 400) the amount of fertilizer calculated according to protein 400 grams / tree + Formula 2: NPK ratio 1: 0.75: (400: 300: 400) the amount of fertilizer calculated according to protein 400 grams / tree + Formula 3: NPK ratio 1: 0.5: (400: 200: 400) amount of fertilizer calculated according to protein 400 grams/tree + Formula 4: NPK ratio 1: 1: (500: 500: 500) amount of fertilizer calculated according to protein 500 grams / tree + Formula 5: NPK ratio 1: 0.75: (500: 375: 500) the amount of fertilizer calculated according to protein 500 grams/tree 10 Xuan Van grapefruit flowers are bright white, inflorescences and single flowers, the average number of wings 4.33 petals / flower, the average number of 28.84 stamens per flower - The morphological characteristics of Xuan Van grapefruit Xuan Van grapefruit has a spherical shape, light yellow skin, smooth surface, average fruit thickness, hollow shaft The average weight of fruits is from 0.913 to 0.945 kg / fruit, the average number of seeds from 124.2 to 128.2 seeds/fruit, the average portion of edible portion is from 52.3 to 54.62% 3.1.2 Growth and development characteristics of Xuan Van pomelo variety - Time occurs buds in the year + The period without bearing fruit: Loc Xuan usually appears from 16 - 22/1, ending from - 12/2 Loc Summer appears from 18/4 - 10/5, ending from - 10/7 Loc Thu appears from August 10 to August 18, ending from September 8-15 Loc Dong appears from - 15/1, ending from - 8/12 + Period bearing fruit: Loc Xuan usually appears from 18 - 25/1, ending from 10 - 15/2 Summer Loc appears from - 12/5, ending from 10 - 16/7 Loc Thu appears from August 16-25, ending from September 15 - 26 - Number and characteristics of flushes in the year + The period without bearing fruit: Spring buds had the largest number of buds, then the Fall buds, Summer buds, and the lowest number were Winter buds Loc Xuan has the largest bud size, followed by Summer buds, Autumn buds and the smallest ones are Winter buds + Fruit bearing period: Spring buds have the largest number of buds, followed by Autumn buds and at least Summer buds Loc Xuan and Summer Loc have bigger sizes than Thu Loc - The relationship between the buds of Xuan Van grapefruit in the bearing period of the 9th year The buds have a close relationship with each other, the first buds are the mother branches of the second buds, the most abundant buds in the Spring crop is followed by the Summer crop and finally the Autumn crop Autumn and previous year branches can be the source of the next spring branch, in which Spring and Summer branches and branches over year old are important mother branches of the next year's branches - The period of differentiation of sprouts of Xuan Van grapefruit The process of differentiation of sprouts of Xuan Van grapefruit appeared 20 days before Dien grapefruit, in the first break on December 1, Xuan Van grapefruit had from 70 to 83.33% of flowering 11 stems, while Dien grapefruit at the 3rd leaf break on December 20, there were only 40 - 43.33% of branches with flowers - Flowering period of Xuan Van and Dien grapefruit: The time of blooming and ending flowering on Xuan Van grapefruit lasts from 22 27, Dien grapefruit lasts from 20 - 25 days - Physiological shedding characteristics of Xuan Van grapefruit The physiological fruit dropping process of Xuan Van grapefruit has the average number of fallen fruits from 9,611.25 - 11,374.25 flowers, fruits / tree and the fruiting rate is from 0.84 to 0.93% Dien grapefruit has the number of flowers and fruits falling from 7,082.25 to 7,494.75 flowers, fruits / tree and the fruiting rate is from 1.08 to 1.11% - Fruit growth dynamics of Xuan Van grapefruit The growth rate of diameter and fruits increased sharply in the period of - 25 and gradually decreased from 55 to 60 days - Fruit ripening period and harvesting time At the stage of stopping growth, Brix pomelo of Xuan Van range from 7.48 - 7.73% and changes significantly within 20 days from the time the fruit stops growing, changes slowly and stops changing at 28 35 days Xuan Van grapefruit is harvested from October to 20 October and ends from the 1st to 20 November, the time from flowering to harvesting lasts from 208 - 220 days 3.2 Study the effect of a number of technical measures on productivity and quality of Xuan Van grapefruit 3.2.1 Study the effect of pruning techniques on the productivity of Xuan Van grapefruit - Influence of pruning on the size of buds Research results in pruning formulas show that pruning according to Khai Tam style and pruning according to the process of the Vegetable Research Institute have a great influence on the size of buds at 95% confidence level compared to control formula - Influence of pruning on flowering time of Xuan Van grapefruit Pruning affects flowering time and prolong flowering time of Xuan Van grapefruit from to days compared to the control formula - Effect of pruning on fruiting rate The observed data showed that pruning formulas had a higher rate of fruiting than the control one: Pruning formulas according to the Vegetable Research Institute procedure achieved a fruiting rate of 1.28 - 1.31%, the pruning type pruning formula reaches from 1.19 - 1.21%, while the control formula reaches only 1.04 - 1.08%, this difference is guaranteed at 95% reliability Table 3.17 Influence of pruning on XuanVan pomelo fruit rate in Yen Son district - Tuyen Quang Formula Fructification rate (%) after flowering 12 In 2015 Control (without pruning) Pruning according QTVNCRQ Trimming Khai Tam style CV % LSD0,05 Năm 2016 Control (without pruning) Pruning according QTVNCRQ Trimming Khai Tam style CV % LSD0,05 to to 10 days 20 days 30 days 40 days 50 days 60 days 10,25 8,28 5,66 3,55 2,23 1,04 10,59 9,42 7,24 5,85 3,89 1,28 10,5 10,30 2,42 8,52 11,60 2,29 7,43 10,40 1,53 4,51 10,80 1,13 2,71 12,10 0,81 1,19 3,70 0,09 10,09 11,62 8,06 9,46 6,22 6,98 4,25 5,12 2,33 3,43 1,08 1,31 10,77 5,20 1,27 8,89 9,10 1,72 6,75 3,60 0,53 4,90 9,30 1,01 3,21 13,90 0,94 1,21 3,40 0,09 - Influence of pruning on components of productivity and productivity Pruning has had effects on fruiting rate and large effect on the number of fruits / tree and productivity, the monitoring results show that pruning according to the Vegetable Research Institute process has a yield of 123.5 - 125 , kg / tree, while the control formula productivity only 92.3 - 96.4 kg / tree, the pruning formulas productivity significantly higher than the control formula with confidence level 95% trust Table 3.18 Influence of pruning on productive components and productivity of Xuan Van pomelo in Yen Son district - Tuyen Quang Formula Control (without pruning) Pruning according to QTVNCRQ Trimming Khai Tam style CV (%) LSD0,05 In 2015 In 2016 Fruit Fruit Number Productivit Number weight weight Productivity of fruits y of fruits (kg / (kg / (kg / tree) / tree (kg / tree) / tree fruit) fruit) 102,3 0,911 93,2 106,3 0,907 96,4 131,3 0,938 123,5 134,3 0,935 125.6 121,7 0,941 114.5 122,3 0,943 116.3 3,80 10,31 2,10 0,04 4,90 12,1 4,10 11,49 2,70 0,05 6,60 16,87 3.2.2 Study the effect of zoning off on the yield of Xuan Van grapefruit 13 - The influence of the time of zoning to the flowering time of Xuan Van grapefruit The time of zoning will affect the flowering time of Xuan Van grapefruit, in which the zoning formula on December 25 gave the plants early flowering - days, earlier than the control formula from to days - Influence of the zest on fructification of Xuan Van grapefruit The data from the monitoring showed that, after 10, 20 and 30 days, the fruiting rate in the formulas was relatively high, the fruiting rate gradually decreased and stabilized after 60 days, in which the circled formula on December 25 reached the highest fruiting rate ranged from 1.25 to 1.29%, while the non-delineated control only reached fractions of 0.87 - 0.92%, this difference Significant at the 95% confidence level Table 3.20 Influence of time of zoning to fruiting rate of Xuan Van pomelo in Yen Son district, Tuyen Quang district Formula In 2015 December December 15 December 25 Control (without zoning) CV % LSD0,05 In 2016 December December 15 December 25 Control (without zoning) CV % LSD0,05 10 days Fructification rate (%) after flowering 30 40 20 days 50 days days days 60 days 11,94 12,60 12,56 10,26 10,71 11,2 7,40 8,03 8,80 4,48 5,24 6,31 2,06 3,17 3,78 1,14 1,22 1,25 10,26 8,20 6,01 4,28 1,46 0,87 6,60 1,47 7,80 1,48 9,30 1,31 8,30 0,79 10,2 0,48 3,10 0,06 12,71 12,27 12,08 9,56 9,25 9,48 6,61 6,91 7,30 5,07 5,11 5,46 3,88 3,57 3,98 1,2 1,24 1,29 10,2 7,8 5,87 3,6 2,13 0,92 4,80 0,98 9,40 1,44 11,90 1,37 16,70 1,38 14,90 0,87 2,50 0,05 - The influence of the moment of zoning to the components of productivity and productivity 14 The monitoring results show that the time of zoning not only affects the rate of fructification but also affects the yield and productivity components, the results show that the time of zoning is high More than the control formula at the 95% confidence level, in which the delineated formula on December 25 yielded 118.4 - 120.1 kg / tree Table 3.21 Influence of time of zoning on the components of productivity and productivity of Xuan Van pomelo in Yen Son district - Tuyen Quang In 2015 In 2016 Fruit Fruit Number Productivit Number weight weight Productivity of fruits y of fruits (kg / (kg / (kg / tree) / tree (kg / tree) / tree fruit) fruit) December 116,6 0,938 109,4 118,3 0,928 109,8 December 15 122,0 0,949 115,8 121,7 0,938 114,2 December 25 130,0 0,924 120,1 128,7 0,920 118,4 Control (without 97,7 0,912 89,1 89,7 0,908 81,4 zoning) CV (%) 4,40 2,80 4,60 2,70 2,60 3,20 LSD0,05 10,13 0,05 8,58 6,12 0,04 6,69 Formula (Circle level on 3.2.3 Study the effect of fertilizer formulas on productivity and quality of Xuan Van grapefruit - Influence of fertilizer formulas on the flowering time of Xuan Van grapefruit Monitoring data showed that there was no difference in the time of flowering, ending flowering between the fertilizing formula and the control formula Influence of fertilizer formulas to the percentage of fruits of pomelos of Xuân Vân The monitoring data showed that after 10 days, 50 days after flowering, stable fruits and fruiting in the fertilizer formulas were higher than the control at 95% confidence level; in 2015, the fructification rate of fertilizer formulas ranged from 1.16 to 1.38%, while that of the control formula reached 1.11%; in 2016, the fruiting rate of fertilizer formulas ranged from 1.22 to 1.40%, while the control formula reached 1.09%; formula ratio of NPK (1: 0.75: 1) with the level of fertilizing 500 grams calculated by protein reaches the highest rate of fructification in years from 1.38 - 1.40% 15 Table 3.23 Influence of fertilizer formulas to the rate of Xuan Van grapefruit fructification in Yen Son district - Tuyen Quang Fruiting rate% after Stable 10 20 30 40 50 Formula fruiting days days days days days rate In 2015 Formula 11,82 8,97 7,71 6,11 2,48 1,21 Formula 10,64 9,12 7,33 5,99 3,49 1,26 Formula 11,91 9,01 8,33 6,25 3,45 1,16 Formula 12,28 9,65 8,07 6,24 3,88 1,32 Formula 11,92 9,83 8,25 5,96 4,03 1,38 Formula 12,23 9,61 7,81 6,07 3,71 1,28 Formula 10,30 8,27 6,05 4,22 2,39 1,11 CV(%) 7,60 7,20 6,30 4,00 10,1 4,6 LSD0,05 1,56 1,18 0,85 0,41 0,60 0,06 In 2016 Formula 12,24 9,01 6,66 4,58 2,61 1,27 Formula 12,13 9,26 6,92 4,76 3.01 1,30 Formula 11,78 8,98 6,42 4,34 2,56 1,22 Formula 11.9 9,50 7,29 5,29 3,45 1,40 Formula 12.36 9,77 7,46 6,61 3,85 1,44 Formula 11,79 9,35 7,09 5,04 3,21 1,35 Formula 10,17 7,87 5,89 2,37 1,38 1,09 CV(%) 6,50 6,20 6,00 8,20 9,90 6,50 LSD0,05 1,35 1,00 0,73 0,93 0,50 0,14 Influence of fertilizer formulas on yield components and yield of Xuan Van grapefruit The monitoring results showed that all fertilizer formulas yielded significantly higher yield than the control formula at the 95% confidence level, in which formula with NPK ratio (1: 0.75: ) with a level of 500 grams of nitrogen applied to yield yield of 135.4 -140.5 kg / tree Table 3.24 Influence of fertilizer formulas on productivity and productivity components of Xuan Van pomelo in Yen Son district Tuyen Quang 16 In 2015 In 2016 Number Fruit Number Fruit of weight Productivity of weight Productivity Công thức fruits / (kg / (kg / tree) fruits / (kg / (kg / tree) tree fruit) tree fruit) Formula 125,7 0,927 116,6 124,3 0,926 115,1 Formula 129,3 0,931 120,4 127,7 0,929 118,6 Formula 123,3 0,924 113,9 122,7 0,923 113,2 Formula 134.7 0,942 126,9 144,3 0,939 135,5 Formula 143,0 0,947 135,4 148,7 0,945 140,5 Formula 131,7 0,936 123,3 135,7 0,935 126,9 Formula 113,7 0,915 104,0 109,0 0,910 99,1 CV(%) 3,70 3,30 5,30 8,00 3,50 6,20 LSD0,05 8,51 0,05 11,27 18,23 0,05 13,22 - Influence of fertilizer formulas to the quality of Xuan Van grapefruit The analysis results showed that the content of dry matter, total sugar, acid content of VitaminC, Brix in fertilizer formulas in fruits were higher than the control formula, this difference was significant at the level of confidence 95% trust 3.2.4 Study the effects of GA3 on the productivity and quality of Xuan Van grapefruit - Effects of spraying GA3 to the rate of fruits of pomelos of Xuân Vân The monitoring results showed that the GA3 supplementation spray formulas all increased fruiting rate, in 2015 fructification rate ranged from 1.46 - 2.08%, in 2016 fructification rate ranged from , 44 1.95%, these results are higher than the control formula with statistical significance at the 95% confidence level Table 3.26 The influence of GA3 spray on the rate of Xuan Van grapefruit in Yen Son district - Tuyen Quang Formula (spraying In 2015 In 2016 GA3 concentration) Total Fruiting Total Fruiting number rate number of rate of (%) flowers (%) 17 flowers track (flower) 10.331,3 10.221,3 10.611,3 10.160,3 10.684,3 10.504,7 track (flower) 50 ppm 2,08 10.520,7 1,95 60 ppm 1,86 9923,7 1,83 70 ppm 1,75 9970,7 1,71 80 ppm 1,69 9945,7 1,62 90 ppm 1,46 10.159,0 1,44 Control (spray water) 0,97 10.274,6 1,03 CV % 4,10 6,10 LSD0,05 0,08 0,10 - The effect of GA3 spray on the yield and the components of the yield of Xuan Van grapefruit The monitoring results showed that spraying GA3 at a concentration of 50 - 90 ppm increased the number of fruits / tree, increased fruit weight and yield at different levels, this difference is statistically significant at the 95% confidence level Table 3.27 Effect of spray GA3 on productivity and productive components of Xuan Van pomelo in Yen Son district - Tuyen Quang Formula (spraying GA3 concentration) 50 ppm 60 ppm 70 ppm 80 ppm 90 ppm In 2015 Fruit Number Productivit Number weight of fruits / y of fruits / (kg / tree (kg / tree) tree fruit) 214,7 0,930 199,8 205,3 190,0 0,936 177,8 181,0 185,7 0,937 174,0 170,7 172,0 0,942 162,0 161,7 156,0 0,950 148,5 146,6 In 2016 Fruit weight Productivity (kg / (kg / tree) fruit) 0,926 190,1 0,931 168,5 0,936 160,1 0,939 151,8 0,951 139,4 - Effect of spray GA3 on some indicators on Xuan Van grapefruit The results showed that fruit height increased when GA3 concentration increased at 90ppm (formula 5), fruit height was from 12.95 - 12.99 cm; control formula (formula 6), fruit height reaches from 11.86 to 11.89 cm Fruit diameter also increased with increasing GA3 concentration and significant difference at 95% confidence The results show that; Spray GA3 at the concentration of 90 ppm, the number of seeds is from 38.3 to 40.9 seeds / fruit only, while the 18 control formula of the number of seeds ranges from 128.2 to 130.2 hat / fruit The proportion of edible portion in the experimental treatments was higher than the control, the difference was significant at the 95% confidence level Table 3.28 Effect of spray GA3 on some mechanical properties of Xuan Van grapefruit in Yen Son district - Tuyen Quang In 2015 In 2016 Percentage Number Percentage Numbe formula The The Diameter of edible of Diameter of edible of (spraying height height (cm) portion seeds / (cm) portion seeds GA3 (cm) (cm) (%) fruit (%) fruit concentration) 50 ppm 12,84 12,27 60,1 111,3 12,80 12,34 60,4 107,4 60 ppm 12,90 12,43 57,6 101,1 12,85 12,58 57,9 95,1 70 ppm 12,92 12,56 58,7 85,4 12,89 12,67 58,5 87,6 80 ppm 12,95 12,67 57,3 63,1 12,92 12,73 57,5 58,7 90 ppm 13,07 12,95 58,4 40,9 13,06 12,99 58,7 38,3 Control (spray 12,64 11,86 54,7 130,2 12,62 11,89 54,1 128,2 water) CV % 1,60 1,80 5,30 8,90 1,40 1,50 4,60 7,60 LSD0,05 0,20 0,20 3,90 10,10 0,20 0,20 3,30 8,30 - Impact of GA3 spray on the quality of Xuan Van grapefruit The analysis results show that the dry matter content, total sugar content and Brix level of fruits in the GA3 spray formulas ranged from 9.92 to 9.98%, from 8.15 to 8.45% and 10.99 - 11.25% compared to the corresponding values in the control formula is 9.85%, 7.96% and 10.97% (2015) In 2016, the dry matter content, total sugar and Brix level of fruits in the GA3 treatment formulas ranged from 10.61 to 10.69%, from 8.49 to 8.73% and 10.94-10 , 99% compared to the corresponding values in the control formula is 10.59%, 8.26% and 10.93% 3.2.5 Study the effect of additional pollination on the productivity and quality of Xuan Van grapefruit - Influence of complementary pollination by different pollen sources on the rate of Xuan Van grapefruit fruit The data show that the experimental formulas achieved relatively high fruiting rate after 10, 30 and 50 days after pollination and 19 achieved a stable fruiting rate from 5.3 to 32.7 (2015) from , 37.7% (in 2016), while the Certified formula achieved fruiting rate from 2.6 to 2.7% The rate of fruiting in pollen secondary treatments was higher than the control formula at the 95% confidence level Table 3.30 Influence of complementary pollination by different pollen sources on the percentage of Xuan Van grapefruit fruiting in Yen Son district - Tuyen Quang In 2015 Formula (additional pollination using pollen sources taken from plants ) sour Grapefruit Dien Grapefruit Cat Que Grapefruit Xuan Van Grapefruit Control (natural) Fruiting rate after pollination 10 days 30 days 50 days 48,70 45,30 39,30 33,30 31,30 40,70 34,70 28,00 19,30 9,30 34,70 28,00 18,70 8,70 2,70 In 2016 Stable fruiting rate (%) 32,70 25,30 15,30 5,30 2,00 Fruiting rate after pollination 10 days 30 days 50 days 50,70 47,30 43,30 37,30 36,00 41,30 36,00 37,30 30,00 28,00 20,00 21,30 9,30 15,30 4,70 Stable fruiting rate (%) 34,70 27,30 17,30 6,00 2,60 - The effect of complementary pollination by different pollen sources on the yield and the components of the yield of Xuan Van grapefruit The results showed that formula yielded from 15.1 to 16.1 kg / formula, formula yielded from 11.7 to 12.7 kg / formula, formula (Control) achieved yield from 1.2 to 1.3 kg / formula, this difference is significant at the 95% confidence level Table 3.31 Influence of complementary pollination by different pollen sources on the components of productivity and yield of Xuan Van grapefruit pomelo in Yen Son district - Tuyen Quang In 2015 Formula (additional pollination using pollen sources taken from plants ) sour Grapefruit Dien Grapefruit In 2016 Number Fruit Productivi Number Fruit Productivi of fruits / weight ty of fruits / weight ty tree (kg / fruit) (kg / tree) tree (kg / fruit) (kg / tree) 16,30 12,70 0,921 0,919 15,10 11,70 17,30 13,70 0,924 0,918 16,10 12,70 20 Cat Que Grapefruit Xuan Van Grapefruit Control (natural) CV(%) LSD0.05 7,60 0,917 7,10 8,60 0,913 7,80 2,70 0,914 2,50 3,00 0,908 2,70 1,00 0,912 0,90 1,30 0,902 1,20 20,80 3,15 2,40 0,04 22,70 3,17 14,10 2,33 2,50 0,04 14,20 2,16 - The effect of complementary pollination by different pollen sources on some indicators on Xuan Van grapefruit The results showed that there were no differences in some parameters of fruit diameter and height The average number of seeds / fruit ranges from 130 - 133.7 seeds / fruit (2015), from 128 - 134.3 seeds / fruit (2016) The share of the meal ranges from 54.6 - 58.7% (2015), from 54.2 - 58.5% (2016) - Influence of complementary pollination by different pollen sources on some quality criteria like Xuan Van grapefruit The analysis results show that the experimental formulas did not have any fluctuation in biochemical indicators when supplemented with pollination 3.2.6 Study the effect of preservation measures on the quality of Xuan Van grapefruit - Influence of preservation formulas to the natural weight loss rate of Xuan Van pomelo Monitoring results show that, after 12 weeks of storage, all storage formulas have a loss of natural mass, of which formula (preserved by smart film) has the lowest natural loss rate verbs 9.49 - 10.18%, the mass loss is significantly different at the significance level α = 0.05 - Influence of preservation formulas to the rot rate of Xuan Van pomelo The monitoring results showed that the percentage of spoilage appeared in the 7th week in the control formula (formula 1), after 12 weeks of storage the control formula had the highest percentage of spoilage, while the formula (preserved by smart film) has the lowest rate of rot - Influence of preservation formulas on the total dissolved solid content on Xuan Van grapefruit The analysis results show that after the process of preserving the dissolved solid content of Xuan Van grapefruit increased gradually during storage, of which: formula (control) had the highest dissolved solids content, while formula has the lowest dissolved solids content - Influence of preservation formulas on the change of total organic acid content in Xuan Van pomelo 21 The analysis results show that, after 12 weeks of preservation, the acid content in formula ranges from 0.320 - 0.334%, formula ranges from 0.331 to 0.346%; Formula ranges from 0.333 to 0.334% and formula ranges from 0.334 to 0.335% These values differ when comparing statistically at the α = 0.05 level - Effect of storage formulas on the change of Vitamin C content in Xuan Van grapefruit The analytical results show that, during preservation, the vitamin C content decreased gradually in all the formulas, the different storage formulas had different vitamin C content decreased at significance level α = 0.05 - Influence of preservation formulas to sensory quality of Xuan Van grapefruit From the results of the analysis of the indicators, the sensory indicators of formula rank well with the highest score from 16.8 to 17.0 points, formula ranks the second with a fairly good grade from 16.0 to 16.4 points, formula ranked third with an average of 14.4 14.6 points, formula ranked fourth with an average score of 11.6 Table 3.39 Quality sensory grapefruit Xuan Van in Yen Son district - Tuyen Quang after months of storage Targets Appearance State inside smell Taste total score Quality rating In 2017 In 2018 Formula Formula Formula Formula Formula Formula Formula Formula 4 3,0 3,8 4,2 4,2 3,0 3,8 4,0 4,2 2,2 3,6 4,0 4,4 2,2 3,8 4,0 4,4 3,0 3,6 4,0 4,0 3,0 3,6 3,8 4,0 3,4 3,4 4,2 4,4 3,4 3,4 4,2 4,2 11,6 14,4 16,4 17,0 11,6 14,6 16,0 16,8 medium medium good good medium medium good good 3.3 Result of building a model of applying technical measures on Xuan Van pomelo in Yen Son district, Tuyen Quang province The results at the model building show that fructification rate ranges from 1.86 - 1.91% (Xuan Van commune); from 1.77 to 1.82% (Thang Quan commune), the control model ranges from 1.12 to 1.15% The average number of fruits / tree in the control model ranges from 109 - 115 fruits / tree, the number of fruits on the model tree that applies the technical measures ranges from 160.1 to 186 fruits / tree The productivity of Xuan Van commune model reaches 158.3 - 173.7 kg / tree; model of Thang Quan commune reaches from 149.7 to 157.5 kg / tree 22 Table 3.40 The components of productivity and productivity of the model applied technical measures on Xuan Van pomelo in Yen Son district - Tuyen Quang Average fruits / tree (fruit) In 2017 Average weight of fruit (kg) Average productivity of fruit / tree (kg) 1,86 169 0,937 158,3 1,77 160,1 0,935 149,7 1,15 115,7 0,907 104,9 8,30 3,90 In 2018 3,60 3,20 1,91 186,0 0,934 173,7 1,82 169,0 0,932 157,5 1,12 109,0 0,913 99,5 5,70 3,30 3,6 6,0 Stable fruiting rate (%) place Xuan Van commune Thang Quan commune Xuan Van commune (control) CV(%) Xuan Van commune Thang Quan commune Xuan Van commune (control) CV (%) The results obtained for see, with an investment of 539,100 VND/ tree, the intensive farming model has a net profit higher than the control from 2.01 - 2.28 times, net profit ranges from 1,995,900 2,064,900 VND / tree Table 3.41 Economic efficiency of intensive farming model of Xuan Van grapefruit in Yen Son district - Tuyen Quang Categories Total expenditure for tree (VND) Total revenue for tree (VND) Net profit (VND) Model in 2017 Xuan Van Thang Quan commune commune Control Model in 2018 Xuan Van Thang Quan commune commune Control 539.100 539.100 470.000 539.100 539.100 470.000 2.535.00 2.560.000 1.265.000 2.604.000 2.535.000 1.199.000 1.995.900 2.020.900 795.000 2.064.900 1.995.900 729.000 23 Profit / cost (VND) 3,70 3,75 1,69 3,83 3,70 1,55 CONCLUSION AND SUGGESTIONS 1.Conclusion 1.1 Xuan Van pomelo grown in Yen Son district, Tuyen Quang province has spherical foliage; - year-old grapefruit growing stably with height 6.84 ± 0.44 m, canopy diameter 7.15 ± 25 m, stem diameter 17.1 ± 1.3 cm and average 9.6 ± 1.5 stems of level 2/tree In the period without bearing fruit, trees produce buds / year and produce buds/year in fruit bearing period; Xuan Loc has the most number of the year Leaves are oval - shaped, light green, with wavy margins Flowers grow single or cluster, bright white, the average number of wings 4.33 petals/flower, the average number of 28.84 stamens per flower only, flowering time from 22 to 27 days; time from flowering to fruit harvest 200 - 220 days; the average fruit rate reaches 0.84 - 0.93% Fruit are spherical, pods are ripe with light yellow color, average weight of fruits is from 0.913 to 0.945 kg; the average number of zones 13.2 zones/fruit; the number of seeds 124,2 - 128,2 seeds/fruit; The share of edible portion was 52.3 - 54.62% Fruit harvest time is concentrated in October and November 1.2 Techniques of pruning, zoning, fertilizing dosage, GA3 spraying, additional pollination have markedly affected the ability of flowering, fruiting rate, yield and quality of Xuan Van grapefruit and protection Smart membrane storage for good quality fruit preservation: Pruning according to the process of the Vegetable Research Institute gave the flower about to days earlier, the highest yield of Xuan Van grapefruit reached 123.5 - 125.6 kg/tree The time of zoning on December 25 gave the plants early flowering - days and gave the highest productivity, reaching 109.4 - 109.8 kg/tree Fertilizing formula at the rate of 1: 0.75: with the application of 500 grams of nitrogen calculated for the highest yield, reaching 133.8 140.5 kg/tree GA3 treatment has affected yield and reduced number of seeds per fruit Spray GA3 with a concentration of 50 ppm for the highest yield, reaching 190.1-199.8 kg/tree Spraying GA3 with a concentration of 90 ppm reduced the number of seeds/fruit, from 128.2 to 130.2 seeds/fruit to 38.3 - 40.9 seeds/fruit 24 Pollination supplemented with pollen source from sour grapefruit increased fruiting rate and yield of Xuan Van grapefruit, stable fruiting rate reached 32.7% and 34.7%; additional pollination by sourcing from sour grapefruit has the highest yield, reaching 15.1 - 16.1 kg / formula Post - harvest Xuan Van grapefruit preserved by smart membrane has reduced the loss of natural weight compared with traditional preservation methods, with the rate of spoilage after 12 weeks of storage at 6.66% and 5.55%; maintaining the criteria to evaluate the quality and trade value of Xuan Van grapefruit 1.3 Application of farming techniques based on the research results of the project to build a model of Xuan Van pomelo in Yen Son district, Tuyen Quang province has increased the productivity from 149.7 to 173.7 kg/trees, net profit increased from VND 1.995.900 to VND 2.064.900/tree compared to the traditional farming methods currently being applied by the people Suggestions The project has studied and identified suitable cultivation techniques for Xuan Van grapefruit variety in Yen Son district, Tuyen Quang province, suggest adding research results to the technical process of planting and tending trees Xuan Van pomelo in Tuyen Quang province; We recommend the use of research and technical advances of the project for Xuan Van grapefruit grown in localities with similar ecological conditions ... Preservative material: Smart film preservatives Polyethylene wax (12% dry matter), Carnauba wax (6% dry matter), red ant resin (2% dry matter), Chitosan (concentration 1.5% ), dry sand 2.3 research content... Hoan (2018) “Study on effects of the growth regulator Ga3 to fruit setting, yield and quality of Xuan Van pummelo in Tuyen Quang province”, Journal of Agriculture and Rural Development, No 15/2018,... Nguyen Thi Hai (2019) “Influence of additional pollination on fruit setting, yield and quality of Xuan Van pummelo in Tuyen Quang province.”,Journal of Agriculture and Rural Development, No 3+4,