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Nội dung luận án: Hiện trạng sản xuất và tiêu thụ xoài tại huyện Phù Cát. + Hiện trạng sản xuất xoài tại huyện Phù Cát. + Tình hình tiêu thụ xoài tại huyện Phù Cát Nghiên cứu một số biện pháp kỹ thuật canh tác nâng cao năng suất và chất lượng giống xoài cát Hòa Lộc tại huyện Phù Cát. + Nghiên cứu xác định kỹ thuật tưới nước phù hợp. + Đánh giá hiệu quả của kỹ thuật tưới nước kết hợp bón phân. + Nghiên cứu xác định biện pháp quản lý dịch hại hiệu quả. + Nghiên cứu xác định biện pháp xử lý ra hoa tập trung. + Nghiên cứu xác định kỹ thuật cắt tỉa phù hợp. Kết quả áp dụng tổng hợp các biện pháp kỹ thuật trên giống xoài Cát Hòa Lộc tại huyện Phù Cát + Tình hình sâu bệnh hại, năng suất và chất lượng quả trong mô hình trình diễn + Chất lượng và hiệu quả kinh tế của mô hình áp dụng kết quả tổng hợp . Những kết quả mới của luận án: Xác định được phương pháp tưới cho vườn xoài giai đoạn kinh doanh bằng ống dẫn thông qua chảo bốc thoát hơi nước (Mini pan) làm tăng năng suất, và tăng lãi ròng so với phương pháp tưới truyền thống. Đặc biệt khi sử dụng phương pháp tưới nước kết hợp với bón phân hòa tan thông qua hệ thống tưới với liều lượng 3kg NPKS + 0,75kg KClcây năng suất thu được tăng lên rất đáng kể. Hoàn thiện kỹ thuật phòng trừ tổng hợp một số sâu bệnh hại xoài chủ yếu bằng biện pháp vệ sinh đồng ruộng, cắt tỉa cành sau thu hoạch, bón phân hợp lý kết hợp với sử dụng đúng phương pháp, có chọn lọc các chủng loại thuốc sâu bệnh có nguồn gốc hóa học đặc trị làm giảm rõ rệt tỷ lệ bị nhiễm, nâng cao năng suất Xác định được kỹ thuật xử lý ra hoa giống xoài cát Hòa Lộc tại huyện Phù Cát có tác động nâng cao tỷ lệ ra hoa và năng suất rõ rệt bằng tổ hợp PBZ + MKP + Thiourea tại các thời điểm tuổi chổi 15 ngày và tuổi chồi 45 ngày
MINISTRY OF EDUCATION AND TRAINING MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT VIETNAM ACADEMY OF AGRICULTURE SCIENCES NGUYEN TAN HUNG RESEARCH SOME TECHNICAL MEASURES TO IMPROVE YIELD AND QUALITY OF CAT HOA LOC MANGO VARIETIES IN PHU CAT DISTRICT, BINH DINH PROVINCE Specialization: PLANT SCIENCE Code: 62 01 10 ABSTRACT OF THE PH.D THESIS IN AGRICULTURE Ha Noi – Year 2023 The project was completed at Vietnam Academy of Agricultural Sciences Science advisor: Advisor 1: Dr Ho Huy Cuong Advisor 2: Professor - Dr Vu Manh Hai Thesis advisor 1: Thesis advisor 2: Thesis advisor 3: The thesis will be defended in front of the Thesis Committee at Vietnam Academy of Agricultural Sciences on month year 20 The thesis can be found at: National Library Library of Vietnam Academy of Agricultural Sciences Library of Agricultural Sciences Institute for Southern Coastal Central of Vietnam INTRODUCTION Urgency of the research With the advantage of high nutritional value and economic value, mango trees in general and Cat Hoa Loc mango varieties in particular have been increasingly occupying an important position in the lives of rural communities in the district Up to now, the area of mango trees has accounted for 0.3% of the total agricultural production area of the district, focusing on a relatively stable commodity farming area with the main variety being Hoa Loc mango Despite this, mango production in Phu Cat district presents basic limitations, in which the instability in yield and fruit quality has been and is significantly reducing the efficiency of cultivation due to the main reason, the main thing is that there has not been a complete farming process, improved to suit the local natural and social conditions, first and foremost the Hoa Loc sand mango variety, which has many advantages compared to other varieties Other mango varieties are present in the whole district Besides, the effects of climate change in recent years have caused droughts, floods, and unseasonal rains, which also have a significant negative impact on mango production Therefore, the implementation of the topic "Study on some technical measures to improve the yield and quality of Hoa Loc mango varieties in Phu Cat district, Binh Dinh province" has a clear urgency in this period of time Aims of the topic From the assessment of the current production status and the application of scientific results on mango trees, the study identified a number of key technical measures to improve the intensive cultivation process of Hoa Loc mango variety grown in Phu Cat district, Binh Dinh province The subjects and scope of the topic 3.1 The research subjects - Cat Hoa Loc mango variety grown from grafted seedlings - About soil: The type of sandy soil is common in mango orchards in Phu Cat district 3.2 The scope of the topic - Regarding the scope of current investigation: In communes of Cat Hanh, Cat Hiep, Cat Lam, Cat Son, investigation period: 2016 - About the scope of internal studies and building models to evaluate research results + The research contents are arranged on mango orchard planted in 2010, density of 238 trees/ha (6m x 7m), planted on sandy soil in Cat Hanh commune, Phu Cat district, Binh Dinh Time to carry out the fruit crop in 2016, 2017 (Irrigation experiment), fruit crop 2018 and 2019 (Irrigation experiment combined with soluble fertilizer through the irrigation system, flower treatment experiment, plant protection experiment) animals, pruning experiments) Scientific and practical significance of the topic 4.1 Scientific significance of the topic The research has provided valuable scientific data on the basis of providing appropriate technical measures for Hoa Loc mango variety in Phu Cat district in particular and Binh Dinh province in general The research results of the topic are references for research, teaching and production of Hoa Loc mango products in Phu Cat district in particular and Binh Dinh province in general 4.2 Practical significance of the topic The research results have identified a number of important technical measures in the production of Cat Hoa Loc mango varieties in the study area, which is a very basic foundation for building and perfecting the specific planting process on a specific ecological sub-region in the direction of goods with high economic efficiency, growers and technical guidance agencies can apply directly to their local production practices New contributions of the topic Contributing to perfecting the process of intensive farming of Cat Hoa Loc mango variety effectively and suitable to local conditions on the basis of research to determine the method of irrigation for commercial mango orchards by drip pipes through drain pans steam (mini pan), integrated pest management methods on two important pests, thrips and anthracnose, concentrated flowering treatment techniques to improve yield, and pruning measures to create tree canopy in the fruiting period in ecological conditions in Phu Cat district, Binh Dinh province Structure of the topic Thesis consists of 137 pages: Introduction (05 pages) Research literature review (36 pages) Materials, content and research methods (17 pages) Research results and discussion (68 pages) Conclusion and recommendations (2 pages) List of published works (1 page) References (10 pages) The thesis consists of chapters, 31 tables, 13 charts, 12 illustrations and 03 appendices The thesis uses 117 prestigious domestic and international references, updated with novelty CHAPTER 1: OVERVIEW OF THE DOCUMENTATION AND SCIENTIFIC BASIS OF THE TOPIC 1.1 The situation of mango production, consumption and research in the world 1.1.1 The situation of mango production, consumption in the world Mango is a tropical fruit tree with high economic and nutritional value Therefore, by the end of 2019, mangoes were grown in 100 countries around the world with a harvested area of 5,588,716 hectares, an output of 55,853 million tons and an average yield of 9.99 tons/ha FAO statistics, 2019) The countries with the largest mango production in the world are India (18.779.000 tons), China (4.771.038 tons), Thailand (3.432.129 tons), Mixico (2.197.311 hectares) and High yields were recorded in Samoa at 36.9 tons/ha, Mali at 23.3 tons/ha, Caboverde at 22.9 tons/ha, Israel at 22.5 tons/ha, (FAO statistics, 2021) 1.1.2 Research status of mango trees in the world * About mango varieties: In Thailand, the most commonly grown mango varieties for commercial purposes are Nam Dok Mai, Nam Dok Mai 04… (Mark A Mossler and J Crane (2009) [76] More than 1,000 varieties of mango have been recorded in India, of which about 30 are used for commercial cultivation, including indigenous varieties of Alphonso, Bangalora, and Alphonso According to P.R Johnson and D Parr (2006) [97], the main mango varieties grown commercially in Australia are Banana, Haden, Irwin, Keitt, Kensington Pride, Kent, Palmer (Zillate), R2E2 and Tommy Atkins * About the density and planting distance of mango trees: Combined results of S.A Oosthuyse (1995) [102] showed that the distance between mango growing households with yields of 10-15 tons/ha/year in South Africa is 12m x 12m (64 trees/ha), 10m x 10m (100 trees) /ha) In India, Singh A.K et al (2012) [105] conducted a test on the effect of growing method on yield of 10-year-old mango orchards, the results showed that individual yield was highest (24.14 kg) /tree) in the method of planting in the square plot with the density of 100 plants/ha and the highest population yield in the method of double row planting (4.1 tons/ha) with the density of 222 plants/ha * Regarding water management: In the Darwin and Katherine regions of Australia, irrigation management for mango trees is based on climatic conditions (evapotranspiration), soil and plant growth characteristics In terms of irrigation time, the newly planted garden is maintained with regular irrigation (except for the rainy season) with the amount of 100 liters/week/plant and using sprinkler irrigation (Y Diczbalis et al, 2006) [114] Similarly, on the basis of soil type, climatic conditions, variety, density and planting distance, water requirements for mango trees in Pakistan are determined between 50 - 400 liters/day/tree (www.dawn.com) ) [116] * Regarding nutritional management for mango trees: Regarding the method of macronutrient fertilization, all the experiments in Pakistan, India, China, Australia and the United States applied macronutrients for mango trees at times: before flowering, after flowering and after fruiting (Shakeel Ahmed et al, 2001 [103]; Zhou Xiuchong et al, 2001 [115]; Babul C Sarker and M.A Rahim, 2012) [49] In contrast, in Kenya and India, due to its dependence on water, it is recommended to fertilize mangoes with the first time after harvest and the second time 3-4 months after the first application (Jurgen Griesbach) , 2003; Horticultureworld.net) [67] [65] * Regarding mango pest and disease management: Pest composition, according to Mark A Mossler and Jonathan Crane (2009) [76], The main pests of mango in Florida are ticks (Oligonychus yothersi, Oligonychus mangiferus, Aceria mangiferae), aphids (Chrysomphalus dictyospermi, Chrysomphalus aonidum, Ceroplastes floridensis, Protopulvinaria pyriformis, Aspidiotus longnerii, Radionaspis inispindica), Morganella inispindica, thrips (Selenothrips rubrocinctus, Frankliniella bispinosa, Frankliniella kelliae) and beetles (Xylosandrus spp.) In the North of Australia, during the mango bud stage (March - April), there is the appearance of leaf beetles, young shoot borers, red thrips and beetles In the pre-flowering, flower-blooming and fruiting period (from May to August), there is the appearance of leaf hoppers, red thrips, bud borers, beetles, fruit stingers and flower hoppers During the fruit development and harvest (August - November) there was the appearance of flower planthoppers, red thrips, fruit flies and mealybugs (Renkang Peng and Keith Christian, 2005) [100] * About harvesting and preliminary processing and preservation: According to J.F Dirou (2004) [68], in the state of New South Wales - Australia, mangoes are harvested when physiologically ripe, shown by the color of the fruit changing from bright green to yellow-green, the beak is full, and the whole fruit is colored Yellow Mangoes are harvested with scissors, keeping the stalk length about cm and not letting the latex from the fruit stalk stick to the fruit After cutting the fruit, conduct preliminary processing and preservation of the mango according to the following steps: Dip the fruit in the detergent solution water Place the fruit on a net for 30 minutes to dry the resin Spray fungicide to control anthracnose Dry the fruit with a drying tube or with a fan Sorting fruits by size and defects of fruit (Usually classified into type 1, type and type for processing; Fruit size is classified as extra large from 10-12 fruits/7kg tray, large type from 14-16 fruit/tray 7kg, medium type from 18-20 fruits/tray 7kg, small type from 22-25 fruits/tray 7kg) Label and pack with plastic tray with insert to avoid collision during transportation Store in a cool dry place at a temperature of 10 - 120C for days Transport to the place of consumption in conditions of temperature 12 - 160C Treat ripening with ethylene (if necessary) Store at a temperature of 18 - 220C 1.2 The situation of mango production, consumption and research in Vietnam 1.2.1 Situation of mango production, consumption in Vietnam In Vietnam, with the characteristics of a country located in the humid tropical monsoon climate, it is generally suitable for the development of mango production in the direction of commodity, present in most ecological regions in the country , in which the concentrated production area is mainly distributed in the Southwest, Southeast, and South Central Coast According to the General Statistics Office, by 2021, the total area of mango cultivation in the country will be 113,900 hectares, the area for harvesting is 88,400 hectares, the output is 999,600 tons and the average yield is 11.30 tons/ha (Nian) Vietnam Statistical Office, 2022) The localities with large mango growing areas compared to the whole country are Son La (19,7 thousand ha), Dong Thap (13.1 thousand ha), An Giang (12.4 thousand ha) and Dong Nai (12.0 thousand ha) ha), Khanh Hoa (8,4 thousand ha) 1.2.2 Research status of mango trees in Vietnam * About breed: In the northern provinces, the production of Yen Chau egg mango, Yen Chau stinky mango, GL1, GL2 and GL6 is mainly developed (Tran The Tuc et al., 2002) [40] In the southern provinces, in addition to indigenous varieties that have been widely developed in production such as Hoa Loc sand, Chu sand, Thanh ca, Buoi mango, Canh Nong, Tuong mango, Bo green sand, and Bo yellow sand (Khanh Bo) Hoa), Cat Moc (Binh Dinh) Recently, foreign mango varieties such as R2E2, Nam Dok Mai, Kiew Sa Very, etc have also been imported, evaluated and expanded production (Pham Ngoc Lieu et al., 2005; Ho Huy Cuong et al., 2005) events, 2006) [25, 9] In addition, the GL4 mango variety imported from Taiwan and the VRQ-XX1 variety imported from Thailand have the ability to adapt and give good yield and quality in some northern provinces of Vietnam (Vu Manh Hai et al , 2010) [19] * Regarding density and planting distance for mango trees: According to the industry standard TCN 487 - 2001, in semi-intensive conditions mango is recommended to be planted with a density of 277 trees/ha with a spacing of 6m x 6m, in intensive conditions mango is recommended to be planted with a density of 416 trees /ha corresponds to a distance of 4m x 6m (Ministry of Agriculture and Rural Development, 2001) [1] * Regarding water management; The survey results on watering mangoes in the concentrated planting area of Binh Dinh show that: Farmers water mangoes by manual method, exploiting groundwater to irrigate each mango tree with a water pipe, each mango tree is made into a tub around the root with a diameter of - 2.5m, each tree irrigate 600 - 800 liters /times and once every 7-10 days (Hoang Vinh et al., 2017) [44] * About nutrition management: According to the industry standard TCN 487-2001, macronutrient fertilizers (nitrogen, phosphorus and potassium) are applied to mango trees at the ratio of 1,4 N : 1,0 P2O5 : 1,4 K2O in the period from the first year to the year In the 9th year, from the 10th year onwards, fertilizer is provided at the ratio of 2N : 1P2O5 : 2K2 O and the details of the amount of fertilizer required for mango trees by year are shown in Table 1.4 (Ministry of Agriculture and Rural Development, 2001) [1] Most authors studying mango trees in our country recommend times to fertilize mango trees: The first application at the time of pruning after harvest with the amount of 60% N, 60% P2O5 and 40% K2O; 2nd application at the time when the leaves on the new shoots are green (preparing for mango flowering) with 40% P2O5 and 30% K2O; 3rd application at weeks after fruit set with 20% N and 15% K2O; 4th application at 8-10 weeks after fruit set with 20% N and 15% K2O (Nguyen Minh Chau et al., 2004; Tran The Tuc, 1998) [3] [ 39] * About handling flowering and limiting fruit drop: Research on the effect of NO3- in some salts on the flowering of Carabao mango variety in the Philippines showed that KNO3 treatment was the most effective, the rate of flowering branches after treatment reached 75%, followed by salt NaNO3 (45%), NH4 NO3 (34%), and finally Ca(NO3 )2 only 15% flowers bloom Untreated formulations barely flowered Not only in the Philippines but also in other mango growing regions around the world, the role of KNO3 has been recognized in the flowering of mango trees In the Argue state of Venezuela, spraying KNO3 at a concentration of 3.6% increased the yield of Haden mango for two consecutive years Meanwhile, the control formula obtained much lower fruit yield and only year of fruiting In South Africa, KNO3 treatment at 2-4% concentration for Tommy Akins, Kent and Haden mango varieties increased fruit retention and increased fruit yield (Vu Manh Hai, 2010) [18] * Regarding the management of pests and diseases of mango: In the South Central Coast region, Ho Huy Cuong et al (2009) [11] found that the occurrence of pests is quite common of fruit flies, green grubs, young branch borers, aphids, mealybugs, and mealybugs , thrips, anthracnose and fruit rot on mango trees in Binh Dinh and Khanh Hoa Le Quoc Dien (2007) [15] said that integrated pest management (IPM) is currently the best measure in preventing pests and diseases on fruit trees in general and mango trees in particular for commercial production GAP -oriented According to the author, integrated pest management measures on fruit trees include the following requirements: Establish natural systems to prevent or reduce pests by intercropping; Using reasonable farming techniques (using disease-free and pest-resistant seedlings, cleaning the garden to eliminate the source of pests to cut off the infection, pruning to create a ventilation canopy, control the height of plants for easy care, balance soil nutrients to stimulate the development of beneficial microorganisms and limit pests, rational fertilization and increase organic fertilizer application, limit the use of foliar fertilizers periodically, apply reasonable planting density, manage weeds, manage water and avoid waterlogging) 1.3 Comments drawn from the study review - With the nature of a country with a humid tropical climate and an abundant land fund, Vietnam is also one of the countries with the advantage of developing mango trees and in fact has formed a number of concentrated growing areas has a good brand name with an increasingly large and stable consumption market - The research works are quite rich and comprehensive on mango trees in the world has obtained many achievements in many fields such as: determining ecological needs, selecting and creating suitable varieties for different growing regions, technical measures related to nutrition management, soil moisture management, pest management as well as preand post-harvest care techniques, preservation and processing - In Vietnam, the scientific research on mango trees, although not long and not really systematic compared with advanced countries in the world, has also achieved some respectable results, in which: The evaluation and selection of promising varieties, adapted for each growing area, garden management measures including flowering treatment, training and canopy creation, nutritional management, pest management really make an important contribution to sustainable commercial mango production - In Binh Dinh, although the mango growing area is still modest, it is also considered as a key area in the South Central region However, mango production in general and Hoa Loc mango variety in particular in particular in the province, first of all in Phu Cat district, still shows instability, both in terms of food sources and orchard management measures is in the context of climate change has been happening with increasing extent, moreover, mango trees, mainly Hoa Loc sand mango variety in Phu Cat district, are grown on sandy soil, poor in nutrients, so it is very susceptible to damage influence of external factors and scientific research, therefore, it is necessary to focus on investing, directly solving the urgent needs of mango products in Phu Cat district CHAPTER II: RESEARCH MATERIALS, CONTENTS AND METHODS 2.1 Research Materials - Mango variety: Cat Hoa Loc mango variety - Soil: Research on sandy soil - Regarding the scope of the current survey: In communes - Regarding the scope of implementation and model building contents + The research contents were arranged on mango orchard planted in 2010, density of 238 trees/ha in Cat Hanh commune Time to carry out the fruit crop in 2016, 2017 (Irrigation experiment), fruit crop 2018 and 2019 (Irrigation experiment combined with soluble fertilizer through the irrigation system, flower treatment experiment, plant protection experiment) animals, pruning experiments) + The model is arranged on a mango garden planted in 2008, with a density of 238 trees/ha, planted on sandy soil in Cat Hanh commune Time to carry out the left crop: 2020 - Fertilizers used in the experiment: NPKS 16-16-8-13S, Urea, KCl, Foliar fertilizers containing B, Zn, Cu and Mo - Mini-pan: A small evaporative pan with a diameter of 60cm, a height of 30cm, made of plastic, inside the pan has a ruler to determine the amount of water evaporated.Drip irrigation pipe: Using a drip irrigation line with pressure compensation 20mm diameter, irrigation pressure 0.5-1.75bar, irrigation flow 0.3-0.5l/h, distance between small heads 0.22m drop 2.2 research content 2.2.1 Current status of mango production and consumption in Phu Cat district 2.2.1.1 Current status of mango production in Phu Cat district 2.2.1.2 The situation of mango consumption in Phu Cat district 2.2.2 Research on some farming techniques to improve productivity and quality of Hoa Loc mango variety in Phu Cat district 2.2.2.1 Research to determine suitable irrigation techniques 2.2.2.2 Evaluation of the effectiveness of irrigation and fertilization (Fertigation) techniques 2.2.2.3 Research to identify effective pest management measures 2.2.2.4 Research to determine suitable flowering treatments 2.2.2.5 Research to determine the appropriate pruning technique 2.2.3 Results of applying general technical measures on Cat Hoa Loc mango variety in Phu Cat district 2.2.3.1 Pests, diseases, yield and fruit quality in the demonstration model 2.2.3.2 Quality and economic efficiency of the model applying the combined results 2.3 Research Methods 2.3.1 Current status of mango production and consumption in Phu Cat district: - Survey method: Using participatory rural assessment (PRA) method combined with knowledgeable interviewer (KIP), prepared questionnaire survey, and field survey - Content of the survey: Soil group, garden age, farming method (pure or intercropping, intercropping object), household farming scale, harvested output/year, changes in harvest output/ years, planting density and spacing, amount and type of fertilizer applied 2.3.2 Research on some farming techniques to improve yield and quality of Cat Hoa Loc mango variety in Phu Cat district 2.3.2.1 Research to determine suitable irrigation techniques - The experiment was arranged in fully randomized block (RCB) with treatments, replicates, each plot consisted of 12 plants, in which plants were in the middle for data monitoring and 10 trees were guarded - Research data were processed according to Gomez's biostatistical method through computer programs IRRISTAT and Statistix 8.2 - Experimental formula includes: R1 Traditional watering * R2 Irrigation with pipes (mini pan)** R3 Drip Irrigation (mini pan) *** R4 Sprinkler irrigation (mini pan) **** - Only implemented in 2017 * Watering when the soil does not guarantee moisture (according to people's experience) ** Manually watering with a water pipe, the irrigation area is the area of the canopy projection that is 1/3 of the canopy radius from the root The amount and schedule of irrigation through (mini pan) is determined as follows: Amount of Amount of water evaporated on the pan to the threshold to be irrigated water for (mm) irrigation January February March April April May liter/m2 30 77 62 44 42 32 ***Each tree uses rounds of drip irrigation wire, ring is 3.5m in diameter, ring is 4.5m in diameter, the irrigation area of each tree is about 19m2, using a 1HP pump to pump directly into the system irrigated through a filter device, irrigated once every 1-2 days depending on weather conditions, the amount of water each time is equal to the amount of plant evapotranspiration (ETc) from the previous watering through the formula ETc = Ep x Kp x Kc **** In 2017, the formula R4 will be added for sprinkler irrigation with a mini Pet, using a evaporative pan (mini pan) to determine the appropriate dose and time of watering, the amount of water and the irrigation schedule determined according to the formula R2 Economic efficiency: Evaluated by Piter's FEM software on perennials 2.3.2.2: Evaluating the effectiveness of irrigation techniques combined with fertilizer application - The experiment is arranged in the style of main plot, two-factor subplot (split-plot) with formulas, replicates, each plot consists of 12 trees, of which trees are in the middle for data monitoring - Research data were processed according to Gomez's biostatistical method through computer programs IRRISTAT and Statistix 8.2 - Experimental Formula: Levels of each experimental factor Watering method Amount of fertilizer (kg/plant) I1 Drip irrigation according to mini pan + traditional F1 3kg NPKS fertilizer F2 3kg NPKS + 0,5kg K2O I2 Drip irrigation according to the mini pan + fertilizing F3 3kg NPKS + 0,75kg K2O completely dissolved through the drip irrigation system Experimental formulas R1: I1+F1 R3: I1+F3 R5: I2+F2 R2: I1+F2 R4: I2+F1 R6: I2+F3 2.3.2.3 Research to identify effective pest management measures 11 However, mango area in Phu Cat tends to be stable from 2015 (220 ha) to 2017 (220 ha) Mango yield in Phu Cat district in particular and Binh Dinh province in general had an unstable increase and decrease in the period 2013 to 2017 due to two main groups of reasons: Firstly: Abnormal changes of weather and climate factors, causing prolonged drought, irrigation water sources not meeting the requirements of plants, plus the occurrence in large quantities The large number of thrips species in the period of budding and young leaves, flowering and fruiting causes the pistil and young fruit to drop a lot Climate change also causes abnormal rainfall, creating conditions for anthracnose to develop harmfully in the stages of bud and young leaves, flowering and young fruit Secondly: Mango growers have not applied synchronously the care process, have not made proper investment and are not proactive in dealing with unusual changes in weather and climate conditions 3.1.2.2 Cultivation method and seed structure * Social factors related to mango farming in Phu Cat: Survey data on social factors has showed that labor force, cultivated area, irrigation water source, consumption mode and investment capital for mango production in Phu Cat district are not factors basic limiting factor The number of main laborers in a household is not much, but with the size of the area not too large, the shortage of human resources will certainly not happen In the field of consumption, the method of bringing products directly to the collection barn, thereby limiting the situation of price pressure when collecting for mango farming households Taking the initiative in own capital to invest in production not only reduces production costs (paying interest when borrowing capital) but also contributes to improving productivity through proactive input of materials to fertilize fertilizer and prevention of pests and diseases at the right time; Only 20% of households have difficulties in farming techniques * Biological factors related to mango cultivation in Phu Cat: Stemming from the market's demand, the area of Hoa Loc mango variety now accounts for a large proportion in production, forming a concentrated commodity production area, creating its own brand, making an important contribution to the country's economy the development of the local economy, improving the lives of workers, especially when the Cat Hoa Loc mango variety is domesticated by most farmers, creating favorable conditions for the synchronous application of technical advances in the area Cultivation to increase yield and product quality 3.1.2.3 Application of technical measures The topography of Cat Hoa Loc mango growing area in Phu Cat district is basically flat land (95% of surveyed households' gardens), which is very convenient for care such as fertilizing, watering, harvesting and transporting The average planting density of the current garden for Cat Hoa Loc mango is 238.0 trees/ha, which is also considered consistent with the recommendations of Binh Dinh Agriculture sector as well as experts (Nguyen Minh Chau et al events, 2005) (Table 3.3) 12 Table 3: Current status of cultivation topography, methods of pest control and planting density in mango cultivation in Phu Cat Evaluation criteria Criteria Value Percentage of households growing on hilly 5,0 land (%) Farming terrain Percentage of households growing on equal 95,0 land (%) Proportion of households unless pests and 20,5 Methods of preventing pests anddiseases are detected (%) diseases Rate of protection against pests and diseases is 79,5 the main (%) Average value (tree/ha) 238,0 Planting density for Hoa Loc sand Coefficient of Variation (CV%) 28,5 mango (n = 97) Standard error (SD) 69,5 Table 3: 4: Current status of fertilizer use in mango cultivation in Phu Cat Evaluation criteria Criteria Value Percentage of households applying organic 57,5 fertilizer (%) Percentage of households applying mixed fertilizer 90,2 NPK (%) Percentage of households applying single nitrogen Fertilizer use situation 5,1 fertilizer (%) Percentage of households applying single 5,5 phosphate fertilizer (%) Percentage of households applying single potash 62,4 fertilizer (%) Percentage of households applying fertilizer more 2,1 than times/fruit crop (%) Percentage of households applying fertilizer 50,4 times/fruit crop (%) Number of times of fertilizing Percentage of households applying fertilizer 30,1 twice/fruit crop (%) Percentage of households applying fertilizer 20,2 once/fruit crop (%) Post-harvest fertilization (trimming, cutting tops) 52,4 Nurturing green leaf buds 41,5 Method and time of fertilization Fertilization after fruit set (3 weeks) 25,0 Fertilization after fruiting (8-10 weeks) 65,1 13 Table 5: Current status of investment in macronutrients in mango cultivation in Phu Cat Evaluation criteria Criteria Value Average value (kg/plant) 35,6 Investment amount of manure (n = 109) Coefficient of Variation (CV%) 89,7 Standard error (SD) 30,4 Average value (gram N/plant) 756,5 Amount of nitrogen fertilizer investment (n Coefficient of Variation (CV%) 77,0 = 193) Standard error (SD) 670,2 Average value (gram P2O5/plant) 800,6 Amount of phosphate fertilizer investment Coefficient of Variation (CV%) 75,9 (n = 192) Standard error (SD) 680,3 Average value (gram K2O/plant) 810,1 Investment amount of potash fertilizer (n = Coefficient of Variation (CV%) 76,6 191) Standard error (SD) 630,1 From the source of survey data and through some of the above analysis, we have found that mango growers in general and with Cat Hoa Loc mango variety in particular in Phu Cat have a relatively firm grasp of fertilization techniques and density plant (Table 3.4, Table 3.5) 3.1.3 The situation of mango consumption in Phu Cat district 3.1.3.1 Consumption chain of mango products The strengths and weaknesses of the mango cycle from producer to consumer in Phu Cat district can be summarized as follows: A concentrated commercial mango area has been created in Phu Cat district with the main mango variety being Cat Hoa Loc Hoa Loc sand mango in Phu Cat district has been recognized by consumers and is always in demand from the stable annual consumption market 3.1.3.2 Classification and post-harvest handling of mangoes Table 6: Amount of collection and method of collecting, classifying and preliminarily processing mangoes of collecting baskets in Phu Cat district Implementation Evaluation Criteria Implementation methods rate (%) - Unlimited quantities 87,5 Ability to collect - Limited quantity by market 12,5 - The producer brings it to the barn 67,5 Collection method - The owner of the barn came to the garden to buy 32,5 - According to the promulgated criteria Classification method - According to the owner's subjective opinion 100 Methods of - According to the recommended procedure preparation and - Simple 100 preservation The results are presented in Table 3.6 It can be seen: The percentage of collection granaries is not limited in quantity is 87.5%, only 12.5% is limited because it depends on the demand of the market at the time of purchase Producers bring mangoes after harvest to the barn for consumption, accounting for 67.5% The classification of mangoes (class 14 1, grade or grade 3) in the transaction between the producer and the barn is completely decided by the barn owner and the classification depends on the subjective will of the barn owner; 100% of barn owners conduct preliminary processing and preservation of mangoes after collection in a rudimentary manner (Table 3.6) 3.2 Research on some farming techniques to improve yield and quality of Hoa Loc mango variety in Phu Cat district 3.2.1 Characteristics of climate, weather, physical and chemical properties of the soil in the experimental area 3.2.1.1 Weather characteristics of the study area Table 7: Set of climate and weather points in the study area Average air temperature (0c) Hours of sunshine (Hour - Hr) Month 2015 2016 2017 2018 2019 2020 2015 2016 2017 2018 2019 2020 22,6 25,0 24,6 23,7 24,3 24,8 190,8 179,0 115,4 89,7 172,7 192,0 23,9 23,2 24,2 23,2 25,8 24,5 209,3 148,4 141,8 186,1 255,7 186,2 26,2 24,4 25,9 25,7 27,4 27,1 274,0 221,8 243,6 250,7 276,1 294,6 27,1 26,8 27,3 27,4 28,8 27,7 296,2 282,8 234,1 278,3 303,5 245,1 29,6 29,4 29,1 29,6 29,8 29,5 306,2 265,1 255,0 285,7 301,3 317,9 Rainfall (mm) Air humidity (%) Month 2015 2016 2017 2018 2019 2020 2015 2016 2017 2018 2019 2020 63,5 55,6 153,2 128,6 303,8 15,6 78 86 82 85 80 83 16,9 34,7 124,8 2,8 0,3 41,9 79 79 81 77 81 81 67,7 5,1 8,0 1,6 0,4 84 85 82 79 82 84 36,2 44,0 20,0 144,3 83 86 82 82 78 81 4,5 41,1 49,7 9,4 117,7 10,5 83 80 81 82 76 80 Source: Binh Dinh Provincial Statistical Yearbook in 2020 Climate and weather conditions in the study area are shown in Table 3.7 3.2.1.2 Soil characteristics of the study area The data in Table 3.8 have showed that the soil in the experimental gardens is poor in nutrients, has poor water retention and manure retention, mild aluminum toxicity and heavy metal residues are within the allowable limits for agricultural land Karma Table 8: Physical and chemical properties of soil (0-20) cm at the experimental site Targets Result Targets Result pHH2O(1:5) 6.4 CEC(cmol/kg) 1,93 pHKCl(1:5) 5,5 Clay(%) 2,0 EC(dS/m) 0,04 Silt (%) 5,0 Org.C(%) 0,32 Sand(%) 93,0 Olsen P(mg/kg) 17,0 -0.1 bar 4,4 Soil water 3+ Exch Al (cmol/kg) 0,16 -0,33 bar 2,4 Note: Source of analysis: Institute of Science and Technology of South Central Coast 15 3.2.2 Research to determine the appropriate watering technique In 2015, the actual yield of the experimental treatments ranged from 14,9 to 18,6 tons/ha and the difference was significant at 95%, showing that irrigation method has a clear impact on yield of mango trees during the business period, in which the drip irrigation method gave outstanding results (18,6 tons/ha) In the 2016 fruit crop, the yield was lower than that of 2015, the drip irrigation method still brought the highest fruit yield (12,5 tons/ha) In 2017, the significant difference between irrigation methods is not only reflected in the yield criterion but also in the number of fruits per tree at the time of harvest with the same trend: gradually increased from traditional irrigation method (lowest) to low-range sprinkler irrigation according to mini pan, to watering with plastic pipes according to mini pan and finally to drip irrigation according to mini pan (highest) The number of fruits per tree of the experimental treatments varied from 144 to 189 fruits/tree, in which the drip irrigation method gave the highest number of fruits per tree (189 fruits), followed by the plastic pipe irrigation method according to mini pan (180 fruits) to low-range sprinkler irrigation according to mini pan (158 fruits) and finally watering according to the traditional method (144 fruits) The actual yield in the experimental treatments ranged from 11,3 to 14.9 tons/ha, ranked from highest to lowest is the drip irrigation method according to mini pan (14,9 tons/ha), irrigated by plastic pipes according to mini pan (14,0 tons/ha), low-range sprinkler irrigation according to mini pan (12,7 tons/ha) and finally the traditional irrigation method Drip irrigation has the highest water use efficiency of 46,1kg/m3 in 2015; 47,5 kg/m3 in 2016 and 114,4 kg/m3 in 2017 Thus, both mini-pan drip irrigation, mini-pan plastic pipe irrigation and mini-pan low-range sprinkler irrigation all have higher water efficiency than farmers' traditional irrigation Economic efficiency of irrigation methods was evaluated by FEM model (Piter C.) Drip irrigation brings the highest economic efficiency to farmers with a profit of 130 million/ha/year Irrigation with plastic pipes according to mini-pan also gives higher economic efficiency than traditional irrigation with a net profit of 122,2 million/ha/year The data along with the above analysis show that, of the four different methods of watering mango trees, the drip irrigation method has the highest water use efficiency It is the advantages of the drip irrigation method that have positively impacted the growth, development and yield of mango trees on sandy soil in Binh Dinh 3.2.3 Evaluation of the effectiveness of irrigation and fertilization (Fertigation) techniques Yields of the experimental treatments ranged from 6,56 to 13,13 tons/ha in 2018 and from 7,03 to 13,70 tons/ha in 2019, the highest was R6 at 13,13 tons/ha (in 2018) and reached 13,70 tons/ha (in 2019), the lowest in 2018 is R2 (6,56 tons/ha) and in 2019 is CT1 (7,03 tons/ha) The number of type fruits in the experimental treatments ranged from 37,33 to 68,43 fruits/tree, the lowest being R1 (37,33 fruits) and the highest being R6 (68,43 fruits) in the year 2018 In 2019, this indicator ranges from 37,33 to 73,33 fruits/tree, the lowest is R1 (37,33 fruits) and the highest is R6 (73,33 fruits) The indicator (%) of grade fruit ranged 16 from 59,80 to 67,53%, the lowest being R5 (59,89%) and the highest being R3 (67,53%) in 2018 In 2019 only This target ranged from 54,76 to 61,63%, the lowest was R5 (54,76%) and especially R3 (61,63%) Table 3.13: Effect of watering and fertilizer on yield of mango tree on sandy soil at Phu Cat, Binh Dinh Number of fruit Percentage (%) of Yield ton/ha type fruit grade Experimental formula 2018 2019 2018 2019 2018 2019 b b b c a R1: I1F1 6,76 7,03 37,33 37,33 61,10 58,13a R2: I1F2 6,56b 7,13b 40,00b 43,96bc 65,66 a 61,03a R3: I1F3 6,60b 7,40b 41,33b 44,66bc 67,53 a 61,63a R4: I2F1 11,26a 12,06a 67,33a 62,30ab 60,10 a 57,83a R5: I2F2 12,23a 13,43a 67,36a 68,76a 59,80a 54,76a R6: I2F3 13,13a 13,70a 68,43a 73,33a 61,26 a 61,46a CV(LL*Faces*Water) 11,82 16,69 25,21 15,60 17,36 24,31 LSD (LL*Faces*Water) 2,32 3,37 23,26 20,49 18,75 29,17 LSD (LL*Faces and 3,11 2,71 20,83 19,95 16,49 24,38 LL*Faces*Water) M I1 6,64b 7,07b 39,55b 41,98b 64,76a 60,26a M I2 12,21a 13,06a 67,71a 68,13a 60,38a 58,02a M F1 9,01a 9,18b 52,33a 59,00a 60,40a 57,98a M F2 9,40a 10,28a 53,68a 56,36a 62,73a 57,90a M F3 9,86a 10,75a 54,88a 57,33a 64,40a 61,55a Note: Values in the same column with different letters represent significant differences at the 95% probability level The yield of the experimental formulas has a statistically significant difference at the 95% confidence level The experimental formulas in the same method of fertilizing according to the traditional method (R1, R2, R3) did not differ from each other and the experimental formulas applied completely soluble fertilizers through the irrigation system (R4, R5, R6) there is no difference, but the yield between the two fertilization methods has a statistically significant difference at the 95% confidence level, which shows that the change of fertilizer method from traditional fertilizer method The traditional method of fertilizing completely soluble fertilizers through the irrigation system has significantly increased mango yield on sandy soil in Phu Cat (Table 3.13) * Economic efficiency Along with the yield factor, the economic efficiency analysis results also show that, when fertilizing completely dissolved fertilizers through the irrigation system, the water efficiency and fertilizer use efficiency increased significantly , in which soluble fertilizer through drip irrigation system (R6) gives the highest yield and is also the formula with the 17 highest economic efficiency, higher than the remaining formulas and higher than the control formula 129 million VND/ha/year, besides that, the rate of return on investment capital of CT6 reached 2,7 times and was also 0,9 times higher than the control 3.2.4 Research to identify effective pest management measures Table 3.15 has showed that, for anthracnose that damages young leaves, the disease rate of the two formulas R1 and R2 fluctuated from 7,50 to 8,00% in 2018, from 7,50 to 8,50% in 2019 and significantly lower at 95% compared to the two formulas R3 and R4 (35,75 and 37,25% in 2018; 35,75 and 37,50% in 2019 respectively) On inflorescence, the rate of anthracnose in formulas R1, R2 and R3 fluctuated from 5,50 – 8,25% in 2018, from 6,00 – 9,00% in 2019 and was significantly lower significance at 95% compared with the R4 formula (disease rate 33,25% in 2018 and 34,00% in 2019) On the contrary, on fruit, the rate of anthracnose disease increased gradually from formulas R1 and R2 (the rate of disease in 2018 increased from 5,75% to 8,50% and in 2019 increased from 6,00 to 9,00%), the highest is the R3 formula (the disease rate in 2018 and 2019 is 23,00%) and the highest is the R4 formula (the disease rate in 2018 is 44,50% and in 2019 it is 45,00%) Table 15: Harm rate of anthracnose Young leaves flower branch Fruit Year R 2018 2019 2018 2019 2018 2019 b b b b c R1 8,00 8,50 5,50 6,00 5,75 6,00c R2 7,50b 7,50b 7,00b 7,50b 8,50c 9,00c R3 35,75a 35,75a 8,25b 9,00b 23,00b 23,00b R4 37,25a 37,50a 33,25a 34,00a 44,50a 45,00a CV% 23,62 23,55 25,00 28,10 30,66 31,91 LSD5% 8,35 8,40 5,39 6,34 9,96 10,59 Note: Values in the same column with different letters represent significant differences at the 95% probability level Table 16: Damage rate of thrips (%) Young leaves Flower Buds Fruit Year Recipe 2018 2019 2018 2019 2018 2019 b b b b c R1 6,75 7,00 6,00 6,00 8,50 9,00c R2 7,25b 7,50b 5,75b 6,00b 8,50c 9,50c R3 33,25a 34,50a 7,50b 7,50b 26,50b 26,75b R4 35,75a 36,50a 36,50a 37,00a 47,25a 47,25a CV% 19,28 20,44 28,35 28,10 30,26 29,70 LSD0,05 6,39 6,98 6,37 6,34 10,98 10,92 Note: Values in the same column with different letters represent significant differences at the 95% probability level The rate of damage of thrips on young leaves of the experimental treatments also tended to be similar to that of anthracnose, the percentage of young leaves showing the presence of thrips was lowest in the treatments R1 and R2 (respectively, the rate of thrips infestation on young leaves was similar to that of anthracnose) are 6,75% and 7,25% in 18 2018; 7,00% and 7,50% in 2019) and significantly lower at 95% than the two formulas R3 and R4 (33,25% and 35,75% in 2018; 34,50% and 36,50% in 2019) On inflorescence, the damage rate of thrips in treatments R1, R2 and R3 fluctuated from 5,75 to 7,50% in 2018; from 6,00 – 7,50% in 2019 and significantly lower in statistical value than the formula R4 with disease prevalence of 36,5% in 2018 and 37,00% in 2019 On the contrary, on fruit, the damage rate of thrips increased gradually from treatments R1 and R2 (harm rate in 2018 was 8,50% and in 2019 was 9,00% to 9,50% respectively), is higher than formula R3 (harm rate in 2018 is 26,50% and in 2019 is 26,75%) and the highest is formula R4 (harm rate in 2018 is 47,25% and in 2019 is 47,25%) (Table 3.16) The research results on control of thrips and anthracnose on mango we have just presented are related to the type of pesticides used The formulas R1 and R2 used different pesticides, but all had similar chemical origin with similar control effect, so the criteria for the percentage of young leaves, flower and fruit damage, both thrips and disease exclamation has no significant difference; In contrast, in formulas R3 and R4 using biological pesticides to prevent anthracnose and thrips at the young leaf and fruit stage, because the control effect of biological pesticides is not high, the rate of anthracnose and the rate of thrips is not high The damage rate of thrips of treatments R3 and R4 was higher than that of formula R1 and R2; Formula R3 had lower rates of anthracnose and thrips damage on fruit than formula R4 because at the fruit development stage, formula R3 used chemical-based pesticides in the permitted list and formula Table 19: Yield criteria of Hoa Loc mango in 2018-2019 in Phu Cat Targets RECIPE R1 R2 R3 R4 CV % LSD0,05 Number of harvested buds Number of fruits harvested/buds Fruit/tree 2018 2019 2018 2019 2018 2019 50,07 a 53,80 a 44,67 a 43,05 a 16,15 12,37 55,72 a 57,05 a 43,97 ab 40,37 b 17,38 13,70 1,55 a 1,32 a 1,47 a 1,22 a 24,51 0,54 1,90 a 1,82 a 1,82 a 1,82 a 11,93 0,35 86,37 ab 88,70 a 68,75 bc 56,47 c 15,07 18,09 104,50 a 103,27 a 78,45 b 64,00 c 9,34 13,07 Note: Values in the same column with different letters represent significant differences at the 95% probability level The number of fruits/tree is an important criterion, which determines the yield of the treatments participating in the experiment Table 3.19 shows that in 2018 the highest number of fruits harvested per tree was R2 (88,70 fruits) The number of fruits harvested per tree of the experimental treatments was different and this difference was statistically significant Various pest control measures have increased the number of fruits harvested per tree In 2019, the data in Table 3.19 also showed that the highest number of fruits harvested per tree of the experimental treatments was R1 (104,50 fruits) In 2019, the experimental formulas had a difference in the number of fruits harvested per tree and this difference was statistically significant Various pest control measures have changed the number of fruits harvested per 19 tree The highest yield of the experimental formulas in 2018 was R2 (12,20 tons), this difference was statistically significant In 2019, this indicator reached the highest R2 (11,62 tons), this difference is also statistically significant Due to the high prevalence of anthracnose and the damage rate of thrips, the yield of formula R3 and formula R4 was significantly lower at statistical value with 95% confidence compared to formula R1 and R2 Besides yield, the rate of grade fruit of the two formulas R1 and R2 reached from 60,00 – 55,62% in 2018 and from 65,17 – 68,90% in 2019, higher than the formulas R3 and R4 formulas only reached from 19,32 – 30,57% in 2017 and from 34,32 – 39,92% in 2019 (Table 3.20) Table 20: Yield, percentage (%) of grade fruit of Hoa Loc mango in 2018-2019 Targets Recipe R1 R2 R3 R4 CV % LSD0,05 Yield (ton/ha) 2018 11,65 a 12,20 a 9,17 b 6,15 c 13,54 2,12 2019 11,37 a 11,62 a 8,70 b 5,12 c 14,56 2,14 Percentage of fruit type (%) 2018 2019 a 60,00 65,17 a 55,62 a 68,90 a 30,57 b 39,92 b 19,32 c 34,32 c 12,08 5,80 7,99 4,83 Note: Values in the same column with different letters represent significant differences at the 95% probability level After years of experiment, the average yield of the formula R2 was 11.91 tons/ha and was the highest in the experiment Thus, the use of existing biological pesticides cannot replace chemical-based pesticides for the high yield of Hoa Loc mangoes and the rate of type fruit over 60.0%, so in addition to the With mechanical measures (pruning pests and diseases, overhanging branches to open the canopy, cover the fruit and clean the field), the use of chemical-based pesticides on the list of allowed use is still the top priority for productivity Hoa Loc sand mango achieved high and the rate of type fruit was over 60.0% 3.2.5 Research to determine concentrated flowering treatment measures The results of the study on the effect of Paclobutrazol on the flowering and fruiting ability showed that there was a significant difference in statistical value with 95% confidence in the percentage of flowering buds between the treatments in the experiment On average of the years of experiment, the rate of flowering shoots of the formula in the experiment increased gradually as follows, the lowest was only 5,4% with the formula R1, and the two formulas R4 and R8 were equivalent and varied from 19,80 – 24,00%, three formulas R2, R5 and R9 are equivalent and fluctuate from 42,30 – 47,90%, the highest is the two formulas R3 and R7 which are equivalent and fluctuate from 67,10 – 73,10% Besides the difference in the percentage of flowering buds, flower bud morphology also differed between the treatments In which, after the stimulation of flowering, the formulas R1, R2, R3, R6 and R7 had normal flower morphology (inflorescence indicated on shoots and shown in Figure of the report) and formulas R4 , R5, R8 and R9 have abnormal flower morphology (both leaves and flowers are on shoots and shown in Figure of the report) (Table 3.21) 20 Table 21: Flowering shoot rate and flowering morphology of Hoa Loc mango in Phu Cat Flowering shoot rate (%) Flower bud morphology Year 2018 Year 2019 Central jar R1 4.20 d 6.60 d 5.40 Normal b b R2 40.80 43.80 42.30 Normal a b R3 67.70 66.60 67.10 Normal c c R4 19.80 19.70 19.80 Unusual (both leaves and flowers) b b R5 43.60 45.60 44.60 Unusual (both leaves and flowers) b b R6 41.70 40.00 40.90 Normal a b R7 71.90 74.40 73.10 Normal c c R8 22.70 25.30 24.00 Unusual (both leaves and flowers) b b R9 48.60 47.20 47.90 Unusual (both leaves and flowers) CV% 20,54 17,33 LSD5% 12,04 10,39 Note: Values in the same column with different letters represent significant differences at the 95% probability level Because the flowering phenomenon is not normal in the formulas R4, R5, R8, R9 and the percentage of flowering shoots is too low in the formula R1, so the monitoring of growth, development, and other indicators is necessary on the yield and yield components of Hoa Loc mango in the experiment was performed only in formulas R2, R3, R6 and R7 Table 22: Yield criteria of Hoa Loc mango in 2018-2019 in Phu Cat Number of harvested Number of fruits Fruit/tree Targets buds harvested/buds Recipe 2018 2019 2018 2019 2018 2019 b b ab a b R2 49,92 51,90 1,77 1,82 77,18 83,07b R3 60,35 a 62,20 a 1,62 b 1,62 a 97,85a 99,20a R6 50,90 b 51,40 b 1,80 a 1,80 a 78,65b 84,07b R7 60,00 a 62,00 a 1,80 a 1,82 a 100,18a 109,90a CV % 2,27 2,05 5,39 8,75 5,84 5,86 LSD0,05 2,03 1,86 0,15 0,24 17,68 14,59 Note: Values in the same column with different letters represent significant differences at the 95% probability level In 2018, the number of fruits harvested per tree ranged from 77,18 fruits to 100,18 fruits per tree, the lowest being R1 (77,18 fruits), the highest being formula R7 (100,18 fruits) In 2019, this indicator ranged from 83,07 fruits to 109,90 fruits, the lowest being formula R2 and the highest being formula R7 (109,90 results) In both 2018 and 2019 the number of fruits harvested per tree of the experimental treatments was different and this difference was statistically significant at the 95% confidence level (Table 3.22) Recipe 21 Table 23: Yield and percentage (%) of grade fruit of Hoa Loc mango 2018-2019 in Phu Cat Yield (ton/ha) Percentage of fruit type (%) Targets Recipe 2018 2019 2018 2019 b b a R2 8,52 8,20 66,82 68,15a R3 12,15a 10,15 a 66,07a 66,17 a R6 6,50 b 6,30 b 65,22a 66,00 a R7 12,90 a 11,22 a 64,32a 68,07 a CV % 14,77 13,49 16,68 2,32 LSD0,05 2,36 1,93 17,51 2,49 Note: Values in the same column with different letters represent significant differences at the 95% probability level After years of experiment, the average fruit yield of Hoa Loc mango variety in treatments R3 and R7 reached from 11,15 to 12,06 tons/ha, while in treatments using potassium nitrate only reached from 6.40 to 8.36 tons/ha, so with the intention of the study is to consider the effectiveness of potassium nitrate in stimulating flowering at the same time to replace thiourea which cannot be recommended because the yield is still low too low even though the percentage of type fruit is over 70,0%, so under current conditions, the treatment of paclobutrazol at the time the young leaves have matured, is changing from bronze to silk green at the first bud or Secondly, nucleation with phosphorus-rich fertilizers and the use of thiourea to stimulate flowering is still the optimal method to handle flowering of Hoa Loc mango in Phu Cat, Binh Dinh 3.2.6 Research to determine the appropriate pruning technique Table 27: Yield and percentage (%) of grade fruit of Hoa Loc mango 2018-2019 Yield (ton/ha) Percentage of fruit type (%) Targets Recipe 2018 2019 2018 2019 R1(Contrast) 5,30c 5,52c 29,10b 41,07b R2 13,20a 12,30a 56,10a 58,90a R3 9,10b 9,30b 65,20a 71,55a CV % 21,43 2,87 30,58 10,12 LSD0,05 3,40 18,36 26,54 6,49 Note: Values in the same column with different letters represent significant differences at the 95% probability level Table 3.27 has showed that there is a difference in the productivity of the formulas participating in the experiment in 2018 and 2019 and this difference is statistically significant When the effect of different pruning measures increased the yield of Hoa Loc mango in Phu Cat For the criterion (%) of grade fruit of the formulas participating in the experiment in 2018 ranging from 29,1 to 65,2%, the lowest was R1 (29,1%) and the highest was R3 (65, 2%) In 2019, this indicator ranges from 41,07 to 71,55%, the lowest is R1 (41,07%) and the highest is R3 (71,55%) The difference between the experimental formulas is statistically 22 significant The application of different pruning measures increased the percentage of type fruit of Hoa Loc mango in Phu Cat 3.3 Results of general application of technical measures on Cat Hoa Loc mango variety 3.3.1 Situation of pests and diseases, yield and quality of fruit in the model applying the combined results The most suitable technical measures in individual experiments have really worked when applied to the production garden Model of application of technical advances using narrow-spectrum chemical-based plant protection drugs (special treatment) with broad spectrum of action, so the rate of anthracnose disease and damage rate of thrips on leaves Young, flowering and fruiting in the model were all lower than those of the control Although there was no difference in fruit weight and flowering rate between the model and the control, the number of harvested fruits/tree in the model was higher (98,10 fruits/tree, 21,5% higher than that of the control model) compared with the control, 80,70 fruits/tree), so the actual yield in the model was significantly higher (12,31 tons/ha compared with 7,50 tons/ha; 37,1% higher) It is noteworthy that, along with the superiority in fruit yield, the percentage of type mangoes in the model was also much higher than that of the control outside the model (73,3% vs 60,7%) (Table 3.29) Table 29: Model applying the results of synthesis of Hoa Loc mango variety Targets Model Contrast Young leaves 7,4 19,0 - Harm rate of anthracnose (%) Flowering 8,0 17,1 Fruit 7,9 15,0 Young leaves 6,2 16,1 - Rate of thrips damage (%) Flowering 11,9 24,9 Fruit 10,0 17,0 - Rate of flowering branches (%) 76,9 70,0 - Number of fruits harvested (fruit/tree) 98,1 80,7 - Weight of fruit (kg/fruit) 0,47 0,40 - Rate of fruit type (%) 73,3 60,7 - Productivity (ton/ha) 12,31 7,500 3.3.2 The quality and economic efficiency of the model applying the combined results The results of the post-preservation quality analysis have showed that the mango fruit in the demonstration model still retained the characteristic qualities of the variety (Brix degree 18,9%, fiber content 2,75%,) Notably, the post-harvest products of the model did not detect residues of harmful microorganisms (Coliforms and E.coli), heavy metals (arsenic and lead) and pesticides (chlorine, phosphorus and chrysanthemum) In terms of economic efficiency, although the total cost of the model applying the combined results is higher than that of the control because it has to calculate the depreciation 23 of the drip irrigation system, the cost of buying bags of fruit and the labor of fruit bags, but Thanks to the savings in watering, spraying and fertilizer costs, the model's net profit reached 250,350 million and 32,00% higher than the control (net profit was 189,2 million VND/ha), Besides, the model's rate of return on invested capital reached 3,15 times and was also 2,88 times higher than that of the control model CONCLUSIONS AND RECOMMENDATIONS Conclusion Weather conditions, climate, soil properties, size of land fund along with local labor sources and investment capital of people in Phu Cat district have basically met the development requirements of Cat mango variety Hoa Loc in particular and in fact has formed a relatively stable consumption chain, meeting the requirements of the consumption market Some of the major limiting factors of mango production in this region are climate change-related pest outbreaks, fertilization regimes, and pest control, especially anthracnose, thrips and thrips Flowering treatments are not suitable, water source is still precarious, postharvest loss rate is quite high, short storage time reduces profit as well as competitiveness of products Main technical measures to supplement and perfect the process of sustainable intensification of Cat Hoa Loc mango variety in Phu Cat district include: - Irrigation of mango orchards that are harvesting fruit by means of a mini pan (mini pan) increases yield by 9-10%, reduces water volume by 34-70% and increases net profit by 21% compared to traditional methods Especially when using the method of watering in combination with fertilizing with a dose of 3kg NPKS + 0.75kg KCl/plant, the yield increased significantly (increased compared to the control of 6,37 tons/ha in 2018 and 6,37 tons/ha in 2018) 6,67 tons/ha in 2019) - Prevention of mango pests by integrated solutions, combining field hygiene, postharvest pruning, reasonable fertilization with the correct and selective use of chemical pesticides Special treatment significantly reduced infection rate, improved yield (increase of 0,4 tons/ha/year compared to control) - Flowering treatment of Cat Hoa Loc mango variety in Phu Cat district by the combination of PBZ + MKP + Thiourea brought good results, the indicators of number of flowering buds, number of fruits/buds, and number of fruits per tree were higher than the control no effect and the combination of PBZ + MKP + KNO3 in which PBZ was treated at 15 days of brush age (R3) and 45 days of shoot age (R7) gave the best results (yield of 11,15 tons, respectively) /ha and 12,06 tons/ha) - The method of pruning the mango canopy according to the process of the Southern Central Institute of Science and Technology (R2: mainly removing level and branches in combination with cutting the tops) has a superior effect compared to the initiation method (R3: removing the tops) remove both level and branches in the middle of the canopy and press the tops) and the instructions of Binh Dinh Agricultural Extension Center (R1: mainly 24 remove branches and pests) with a net profit of 159,6 million VND/ha (72,9 million higher than R3, 143,1 million higher than R1) General application of technical measures obtained from the project in the form of a demonstration model has limited the harmful effects of thrips and anthracnose, improved yield (12.31 tons/ha/year, high than the control 4.81 tons/ha/year), increasing the economic efficiency (32.0% higher than the control) Recommendations It is recommended that mango growers in Phu Cat district and other districts with similar conditions in Binh Dinh province should apply technical measures in mango orchard management shown in the application model of the combined results of the study LIST OF DISCLOSED SCIENTIFIC WORKS RELATED TO THE THESIS Nguyen Tan Hung, Hoang Vinh, Ho Huy Cương, Phạm Vu Bảo, Tran Dinh Nam, Nguyen Thai Thịnh, Richard Bell, Sudender Mand (2018), “Effect of improved irrigation technologies on yeld of mango graown on sandy soils in Binh Dinh province” Journal of Viet Nam Agricultural Science and Technologi No.1(3)/2018: page 45-52 Nguyen Tan Hung, Le Thi Trang, Ho Huy Cuong, Vu Manh Hai, Tran Thi Hue Huong (2022), "Study on suitable pruning measures for Hoa Loc sand mango in Phu Cat district, Binh Dinh province" , Vietnam Journal of Agricultural Science and Technology- No 08(141)/2022: pages 60-64