MINISTRY OF EDUCATION AND TRAINING MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT VIETNAM ACADEMY OF AGRICULTURAL SCIENCES - VU VAN KHUE STUDY ON SOME CULTIVATION TECHNIQUES TO IMPROVE PRODUCTIVITY AND QUALITY OF HOT CHILLI (CAPSICUM ANNUUM L.) IN BINH DINH PROVINCE Subject: Crop Science Code: 62 01 10 SUMMARY AGRICULTURAL DOCTORAL THESIS Ha Noi – 2018 This Thesis is completed at: VIETNAM ACADEMY OF AGRICULTURAL SCIENCES Science supervisors by: Prof, Dr, Tran Khac Thi Dr, Hoang Minh Tam Critic 1: Critic 2: Critic 3: The thesis is defended at Institutional level Council for Thesis Assessment in: Vietnam Academy of Agricultural Sciences This Thesis can be referred to at: Vietnam National Library; The Library of Vietnam Academy of Agricultural Sciences; The Library of Field crop Research Institute; INTRODUCTION The urgent of project Hot Chilli (Capsicum annuum L.) is one of high-value spice vegetables using in Vietnam and many countries in the world There are some kinds of using such as fresh , dried chilli powder , chilli sauce, ingredient in some special sauces, pickled vinegar, canned fruit, etc., so there is a huge potential for production of chilli In the world, the total area of fresh and dried chilli increased from 2.94 million hectares in 1994 to 3.63 million hectares in 2014, yield increased from 14.88 million tons in 1994 to 36.14 million tons in 2014 and production value reached 1.93 billions USD in 1994 to $ 30.60 billions USD in 2014 (Faostat, 2017) In Vietnam, chillis have been cultivated for a long time Due to the fact that, the chillis are suitable for many different lands, there is a great potential for expanding cultivated area of this crop In particular, in recent years, many places have successfully implemented a model of chilli cultivation for export purposes, thus it opens a new direction for farmers to change their crop structure to produce products with high income In 2013, our country exported about 3,563 tons of dried chilli, chilli powder which valued at 4.665 millions USD (Faostat, 2017) In Binh Dinh, hot chilli is an important vegetable in the crop structure in some localities, in addition to meeting the domestic consumption demand in the province, this is also a commodity for export with high economic value However, in recent years, some localities have rapidly expanded area of chilli for export, which has revealed many limitations such as too many varieties (about 20 varieties) but those varieties are not stable due to new varieties have been introduced regularly every year that their adaptation has not been carefully evaluated.; furthermore, another reasons are lack of organic manure, lime and excessive inorganic fertilizer compared with standard recommendation, the rate of fertilizer is not balanced with the physiological needs of chilli, improper use of pesticides and IPM in pest management have not been properly addressed Due to a dependence on export market, most farmers focus on production of chilli in the Autumn-winter and Winter-spring crop season (September – April next year) During this period, the weather conditions in Binh Dinh province has two months of heavy rains (October and November), so soil moisture and air humidity are always high In addition, low temperature and less lighting duration that have created favorable conditions for raising of pests and diseases, especially the anthracnose disease at harvest stage has significantly affected the chilli production in this local Moreover, cultivation is not planned and market is not forecasted which lead to always fluctuate of chilli price and unstable market Those above limitation factors are main reasons affecting to productivity and efficiency of hot chilli production in Binh Dinh province Therefore, in order to have a sustainable development in the next period, there should be a consistent investment in infrastructure, research and selection of chilli varieties which have high yield and good quality Besides, it is necessary to study and propose some reasonable cultivation methods For these reasons, the implementation of the project “Study on some cultivation techniques to improve productivity and quality of hot chilli (Capsicum annuum L.) in Binh Dinh province” is an urgent requirement for local hot chilli production Objectives of subject Evaluate current status of hot chilli production in Binh Dinh province; identify new hot chilli varieties which are suitable for export markets; and reasonable technical solutions to improve productivity, quality and efficiency of this spicy vegetable production in Binh Dinh province Scientific and practical significances of the research 3.1 Scientific significance - The results of this project have contributed to the development of scientific basis in the exploitation and rational use of natural resources as well as appropriate cultivation techniques to improve the quality and effectiveness of hot chilli production in Binh Dinh province - The topic has been contributed to the knowledge of hot chilli production in the Central Region which will be a reference for scientists, technical staffs and authorities in their research activities, teaching, production, business, and policy making 3.2 Practical significance - The subject has identified basic socio-economic, biological and abiotic constraints to spicy chilli production in Binh Dinh province - It has been identified that the spicy chilli Solar 135 has good yield, good quality, resistance to some major pests and diseases Besides, the subject has identified the best feasible fertilizer and rootstocks These results meet the urgent need in the development of hot chilli production in Binh Dinh province New contributions to the thesis - Evaluated the current status of hot chilli production in Binh Dinh province, thus giving some research directions to overcome the limitations, contributing to help farmer improving their chilli production - Selected and introduced new variety chilli Solar 135 for chilli production which produces high productivity, good quality and suitable with ecological conditions of Binh Dinh province Since then, it has contributed to the diversification of high-yield chilli varieties in production - Recommended feasible level of fertilizer nitrogen, potassium and calcium for new hot chilli variety Solar 135 on Orthic Acrisol soil in Binh Dinh province which is 150 kg N: 150 kg K2O: 500 kg CaO applied on a basal fertilizer of 20 tons of manure and 100 kg P2O5/ha - Applied the combination of identified promising technical methods in Orthic Acrisols soil in Binh Dinh province which has increased productivity by 21.6% (from 25.7 tons/ha to 32.8 tons/ha); net profit from 201.8 million Dong to 278.7 million Dong; and profitability ratio from investment capital from 1.6 to 2.4 in comparision with traditional farming practices The objects and scope of research 5.1 Research objects: Hot chilli varieties are collected from domestic and foreign sources; macronutrients fertilizer N, K2O (Urea, potassium cloride), secondary nutrients fertilizer Ca (Lime powder) which are implemented in the Winter-spring crop on Orthic Acrisol soil 5.2 Location, time - The investigation process took place in districts of Binh Dinh: Phu Cat and Phu My - Experiments were conducted at the Agricultural Science Institute for Southern Central of Vietnam, Quy Nhon city and at Phu My district, Binh Dinh province, from 2012 to 2017 5.3 The scope research The research focus on the Orthic Acrisols soil in Winter-spring crop, technical solutions on seeds; dosage and ratio of nitrogen, potassium, calcium; as well as grafting technique for hot chilli Thesis structure The main thesis has 161 pages which typed in A4 size with 39 tables of data, pictures The thesis consists of parts such as Introduction (5 pages), Chapter I: Overview of research literature (40 pages), Chapter II: Materials, content and research methodology (12 pages), Chapter III: Results and Discussion (84 pages), Conclusion and Recommendations (2 pages) and reference (10 pages) CHAPTER I LITERATURE REVIEW The thesis has reviewed and summarized 45 Vietnamese papers and 60 English papers, news articles from websites with relevant contents including Origin, distribution and classification of hot chilli; Nutritional value and economic value of hot Chili; The requirement the external conditions of hot chilli; Status of hot chilli production in the world and in Vietnam; Status of research on hot Chili in the world and in Vietnam The collected data show that: - The condition of soil and climate in Binh Dinh province is basically favorable for the production of annual crops in general and chilli in particular, and agriculture plays a major role in the socio-economy of Binh Dinh province; the value of agriculture production accounted for 32.8 - 39.0% of the total product in this province - Chilli is one of the main vegetables contributing to the total value of vegetables, beans, flowers and ornamental plants - Chilli is a vegetable with high nutritional value, which is an important source of vitamins for the people population in the world Furthermore, antioxidants such as vitamins C, E, and vitamin A are found in a variety of different types of hot chilli Chilli is also a source of carotenoids, xanthophylls and it contains large amounts of vitamin P (Citrin), B1 (Thiamin), B2 (Riboflavin) and B (niacin) In addition, chilli has a higher amount of vitamins C and A than the recommended dietary sources - According to FAO (2017), the area, yield and quantity of Asian countries are dominating and China is the leading country in terms of cultivated area and quantity of fresh chilli, while India is the leading country in terms of cultivated area and quantity of dried chillies, chilli powder - In Vietnam, chilli is a traditional crop but the area is small, productivity is low Investments in chilli research are not focused so the results are limited In recent years, some researches on chilli cultivation techniques such as seasonal crops, fertilizers, planting density, irrigation, etc have been paid attention by researchers but the growth in cultivated area and productivity is still not matched the potential - Many varieties of hot chilli have high yield, good resistance to adverse environmental conditions, disease resistance (anthracnose, green wilt, virus ), good quality fruit to export standards ( fruit color, fruit size, spicy ) has been successfully created by agronommists inside and outside the country These varieties are extremely rich and precious materials to be used for research on the selection of spicy chilli varieties which adapted to the conditions of soil, climate and socioeconomic of Binh Dinh province - The integrated pest control techniques applied on chilli have significantly reduced the damage caused by anthracnose, root rot and bacterial wilt - Domestic research as well as international research on rootstock for grafting are mainly focused on Phytophthora capsici and bacterial wilt (Ralstonia solanacearum) The successful research on the rootstock against these two diseases will help to reduce the risk and economic loss for chilli growers - Chilli plant is sensitive to organic fertilizer and mineral fertilizers The proper use of fertilizer will improve the quality of chilli products The amount of nitrogen, potassium as well as calcium recommended in the study for different areas ranged from 75-300 kg/ha, 60-150 kg K2O/ha, calcium 500-800 kg lime powder Therefore, it is necessary to have specific research to have reasonable basis for fertilizer application for Binh Dinh province - In order to improve the soil, increase organic matter and amount of beneficial microorganisms in chilli cultivation, organic fertilizers can be used in the range of 825 tons/ha and solutions extracted from poultry manure These above achievements are the basis for scientific application to production practices, or used in research to find appropriate farming techniques to improve hot chilli production in Binh Dinh province CHAPTER II MATERIALS AND RESEARCH METHODOLOGY 2.1 Research Materials - The varieties used in the variety selection consist of: 18 hot chilli varieties collected from different sources from within the country and abroad - The varieties used in the study of grafting rootstock: 05 varieties were collected from Ninh Thuan, Khanh Hoa, Binh Dinh, Thua Thien Hue and Nghe An provinces - Fertilizers: Manure (cow manure), urea fertilizer, superphosphate, potassium chloride, calcium (lime powder) - Domestic and foreign references related to the thesis - Soils for experimentation were Orthic Acrisols soil 2.2 Research Contents 2.2.1 Evaluate the current status of hot chilli production in Binh Dinh province 2.2.2 Determine hot chilli variety which adapted to soil and climate conditions in Binh Dinh province 2.2.3 Determine the dosage and ratio of nitrogen, potassium and calcium to hot chilli grown on Orthic Acrisols soil in Binh Dinh province 2.2.4 Study on the effect of different rootstocks on the growth, yield and disease resistance of Solar 135 variety 2.2.5 Evaluate the application of trial results to yield and quality of hot chilli on Orthic Acrisols soil in Binh Dinh province 2.3 Research Methodology 2.3.1 Survey method, collecting information to evaluate the current status of hot chilli production in Binh Dinh province - Inherit related secondary information which was collected from Binh Dinh Department of Agriculture and Rural Development, Phu Cat District and Phu My District People’s Committee, Cat Lam Commune People's Committee, Phu Cat District and My Hiep Commune People's Committee, Phu My District and Binh Dinh Statistical Office; - Surveys were conducted in Phu Cat and Phu My districts through questionnaires - Use PRA method to collect information; interview with a knowledgeable person (KIP) and group interview to review and supplement information; SWOT analysis to assess strengths, weaknesses, opportunities and challenges in cultivation; - Analyze statistical survey data using Microsoft Excel 2010 software - Implementation time: 2013 2.3.2 Experiment designs for selecting promising hot chilli variety which is adaptative to soil and climate conditions in Binh Dinh province 2.3.2.1 Experiment on hot chilli variety separation - The experiment was arranged by the method of Augmented RCB Design, divided into blocks There are two control varieties and 16 tested varieties, each block has control varieties The tested varieties are arranged sequentially without repetition, the area of the experiment is 14m2 (10m x 1.4m) - The experiment was conducted in the Winter-spring crop of 2012 - 2013 at the net house of Agricultural Science Institute for Southern Central of Vietnam – Area 8, Nhon Phu Ward, Quy Nhon, Binh Dinh Province 2.3.2.2 Experiment on the evaluation of promising hot Chili varieties: - The experiment was arranged in Randomized Complete Block Design (RCBD), repeated three times, the plot area was 14m2 (10m x 1.4m), monitoring trees in each plot - The experiment was conducted in the Winter-spring crop of 2013 - 2014 and the Winter-spring of 2014 - 2015 in My Hiep, Phu My district, Binh Dinh province on Orthic Acrisols soil 2.3.3 Research methods to determine the appropriate dosage and ratio of nitrogen, potassium and calcium 2.3.3.1 Experiment 1: Study the effect of different doses and rates of nitrogen and potassium on growth, development and yield of Solar 135 variety - The experiment was arranged in the split-plot design, in which the main factor was potassium fertilizer, the sub factor was nitrogen fertilizer; there was replicates, the area of the plots was 14m2 including the trench beds (10m x 1.4m), monitoring trees in each plot - Experiment conducted in the Winter-spring crop of 2015 - 2016 and the Winter-spring 2016 - 2017 in My Hiep Commune, Phu My District, Binh Dinh province - The amount of fertilizer used per hectare is: + Basal fertilizer: 20 tons manure + 100 kg P2O5 + 500 kg lime powder + Nitrogen factor: N1 = 360 kg N (Based on farmer practice - control); N2 = 200 kg N; N3 = 150 kg N + Potassium factor: K1 = 350 kg K2O (Based on farmer practice - control); K2 = 200 kg K2O; K3 = 150 kg K2O - Experimental treatments: N1K1, N1K2, N1K3, N2K1, N2K2, N2K3, N3K1, N3K2, N3K3 (Control treatment: N1K1) 2.3.3.2 Experiment 2: Study on the effects of nitrogen and calcium doses on growth, development and yield of Solar 135 variety - The experiment was arranged in the split-plot design, in which the main factor was calcium fertilizer, the sub factor was nitrogen fertilizer; there were replicates, the area of the plots was 14m2 including the trench beds (10m x 1.4m), monitoring trees in each plot - Experiment conducted in the Winter-spring crop of 2015 - 2016 and the Winter-spring 2016 - 2017 in My Hiep Commune, Phu My District, Binh Dinh Province - The amount of fertilizer used per hectare is: + Basal fertilizer: 20 tons manure + 100 kg P2O5 + 160 kg K2O + Nitrogen fertilizer factor: N1 = 360 kg N (Control); N2 = 200 kg N; N3 = 150 kg N + Calcium factor: C1 = 350 kg CaO (Control); C2 = 500 kg CaO; C3 = 800 kg CaO - Experimental treatments: N1C1, N1C2, N1C3, N2C1, N2C2, N2C3, N3C1, N3C2, N3C3 (Control: N1C1) 2.3.4 Research methods to investigate the effect of different rootstocks on growth, yield and disease resistance of the chilli variety Solar 135 - The experiment was arranged in Randomized Complete Block Design (RCBD), repeated times, with graft combination (rootstocks varieties are Binh Dinh Purple chilli, Khanh Hoa White chilli, Ninh Thuan Xiem hybrid chilli, Hue Bom and Catu Nghe An, the scion was Solar 135 variety, and a non-graft control (Solar 135 ) The plot area was 14 m2 including beds (10m x 1.4m) - Experiment conducted in the Winter-spring crop of 2015 - 2016 in My Hiep Commune, Phu My District, Binh Dinh 2.3.5 Research methods for evaluating the application of research results to the productivity and quality of hot chilli on Orthic Acrisols soil in Binh Dinh province The trial was carried out on Orthic Acrisols soil in My Hiep Commune, Phu My District in the Winter-spring crop of 2016 - 2017 with two cultivation methods: traditional farmer cultivation and test results of the project * Traditional farmer cultivation: using traditional varieties and cultivation techniques * Cultivating trials according to the research results of the project: Using new varieties and improved cultivation techniques 2.3.6 Monitoring parameters and monitoring methods Parameters and monitoring methods are applied in accordance with procedures approved by the Ministry of Agriculture and Rural Development of Vietnam (MARD) QCVN 01-64: 2011/BNNPTNT to evaluate the value of cultivation and using of hot Chili These include: growth parameters, morphological characteristics and quality of fruits, components of yield and yield, and pest and disease status 2.3.7 Data processing and analyzing methods - Method of data analysis: Using the Microsoft Office Excel 2013 and Statistix 8.2 software to process statistical data in the evaluation of current status, selecting varieties and cultivation techniques - Analytical methods of economic efficiency: Use economic analysis of crop to analyze efficiency as follows: Total value of income (GR) = Yield x Average selling price; Total Variable Cost (TVC) = Cost of materials + Labor cost + Energy cost + Investment capital rate; Profit (RVAC) = GR - TVC; Return on investment (VCR) = GR / TVC CHAPTER III RESULTS AND DISCUSSION 3.1 Evaluate the current status of hot chilli production in Binh Dinh province 3.1.1 Status of production of hot chilli in Binh Dinh province - Status of social factors: The majority of households with a production area of 1,000 - 5,000 m2 should have feasible conditions to invest in intensive farming and commodity products However, difficulties in selling products; lacking of good varieties for production; lacking of information on new techniques; and lacking of capital in production are social factors which limit production of chilli in Binh Dinh province - Status of biological factors: + Hot chilli variety: 95.8% of area is reserved for pointing-down chilli varieties while only 4.2% is for pointing-up and local varieties + The average yield of pointing-down chilli varieties is 20.4 tons/ha while the pointing-up chilli group is only 14.8 tons / + 100% of chilli growers were surveyed stating that they bought F1 hybrid variety from local agents The rate of using F1 seeds is 100% for the pointing-down chilli varieties and 86.0% for the pointing-up chilli varieties + Thrombocytes, bed bug, red mite, deep borer, fruit borer, root rot, root borer, bacterial wilt and anthracnose are common pests and diseases in chilli production In particular, anthracnose is the most common disease in the surveyed households, at rate of 93.3% - Status of abiotic factors: + Some common cultivation techniques such as making beds, covering bed with nylon, plant density and method of planting, watering and trimming methods are reasonably applied by farmers + Fertilizer application: Compared with the recommended procedure, over 80% of the households did not apply enough manure and lime, while 100% of the households applied above double times of nitrogen and potassium, and from 3.5 to 7.0 times of phosphorous fertilizer The ratio of fertilizer N, P, K the households used to apply for chilli is: 1: 1,25: + Pesticides application: The use of pesticides in hot chilli cultivation in Binh Dinh province presents many limitations, most of which not follow the principle of "four right" in the use of pesticides + Consumption of chilli products: In Phu My district, there are centralized purchasing agents for export, apart from preliminary processing, some agents invest to build cool storage system for preserving and processing However, prices are uncertain and depended largely on a traditional market 3.2 Identification of hot chilli adapted to soil and climate conditions in Binh Dinh province 3.2.1 Isolation of hot chilli group in the Winter-spring crop 2012 - 2013 3.2.1.1 Morphological characteristics and fruit quality s of hot chilli varieties Results show that: - Fruit shape in the longitudinal section: fruit shape in the longitudinal section of most varieties is triangular, which is suitable for market demand and is one of the criteria required for exporting Only two local varieties, Xiem Hybrid and Hue Bom, have the shape of fruit in the longitudinal section as “bull horn” This fruit type is short and curved which is less favorable on the market, especially for export - Fruit length: Varieties with fruit length ranges from 10.6 to 17.5 cm, in which the shortest is Xiem Lai and Bom Hue varieties,at 10.6 and 10.8 cm respectively These two varieties are shorter than two control varieties from 2.0 to 2.4 cm Among remaining varieties, there are dominant varieties, VRQ3 and VRQ4, which are 16.0 and 17.5 cm, respectively They are higher than the control varieties from 3.0 - 4.7 cm, other tested varieties are equivalent or not significantly different compared to the control varieties 11 and Super 20 (29.3 tons/ha) ), yield of remaining varieties ranges from 23.1 to 28.7 tons/ha 3.2.1.5 Status of pests and diseases of hot chilli The results of monitoring of pests and diseases showed that: - Anthracnose: The level of damage ranged from 2.4 to 7.5%, in which the most seriously affected varieties were Xiem hybrid (7.5%), the less affected ones were Koregon and Solar 135 (only 2.4 - 2.6% was affected), lower than the control varieties from 2.0 to 2.9% - Root rot: Among the 18 experimental varieties, only varieties were damaged: Hue Bom 6.1%, Siam Lai 8.1% and VRQ3 12.2%, the remaining varieties are not affected (0%) - Bacterial wilt disease: Only four infected varieties were Hue, Xiem hybrid, VRQ3 and PP9955-15 with the rate of suffered plants from 2.0 - 4.1%, the remaining species were not infected with bacterial wilt disease Thus, from the abovegroups of 18 varietiesand lines, there are six promising varieties were selected for further evaluation which have high yield and good resistance to pests and diseases such as: Super 20, TN356, Nun, Koregon, Solar 135, Hot chilli and control variety TN185 3.2.2 Evaluate the promising hot chilli varieties in the Winter-spring crop 2013 2014 and the Winter-spring crop 2014 – 2015 3.2.2.1 Growth duration of experimental varieties - Time from sowing to transplanting: Similar to the winter-spring crop of 2012 2013, the time from sowing to emergencing among varieties ranges from to days and from sowing to transplanting from 30 to 32 days in both two crop seasons - Time from sowing to 50% of plant flowering: time from sowing to 50% of plants flowering of the two crop seasons varies from 33 to 41 days On the other hand, in the same season, this factor of different varieties varies from 1-7 days, while between two seasons; the varieties also vary from to days - From the first harvesting time to the end of harvest: The first harvest time in both crops ranges from 93 to 97 days and finishing harvested time varies from 136 to 147 days in the Winter-spring crop of 2013 – 2014, and from 138 to 145 days in the Winter-spring crop of 2014-2015 3.2.2.2 Growth capacityof hot chilli varieties - Plant height: In the Winter-spring crop of 2013 - 2014, plant height varies from 84.4 to 121.4 cm In the Winter-spring crop of 2014-2015, plant height varies from 85.2 to 120.6 cm, in which the experimental varieties have lower plant height, from 12.7 - 27.0 cm compared to TN185 (control variety) - Canopy diameter: Similar to plant height, the diameter of canopy among different varieties also has a large difference, it ranges from 72.6 to 93.2cm (difference from 0.6 to 20.6cm) in both season times However, in the same variety, there is a negligible difference in the Winter-spring 2013 to 2014 compared to the Winter-spring crop 2014 - 2015 (difference from 0.3 to 3.1cm) 3.2.2.3 Components of yield and yield of hot chilli varieties Monitoring data is presented in the table 3.14: 12 Table 3.14 Components of yield and yield of hot chilli varieties in Winter spring season in 2013 - 2014 and Winter-spring season in 2014 - 2015 in Phu My district, Binh Dinh province Criteria Variety TN185 (Control) Super 20 TN 356 Nun Koregon Solar 135 Hot Chilli CV (%) LSD0.05 Number of plants/plot (plant) First Second crop crop Fruits/plant (fruit) Average weight of fruit (gram) First Second First Second crop crop crop crop Potential yield (tons/ha) First Second First Second crop crop crop crop 49.0 ± 0.0 47.7 ± 1.2 51.6d 52.2d 15.3a 14.6a 27,6c 49.0 ± 0.0 48.3 ± 1.2 47.7 ± 0.6 49.0 ± 0.0 49.0 ± 0.0 49.0 ± 0.0 33,0b 36,3a 35,5ab 35,2ab 36,4a 37,4a 4.91 2.96 49.0 ± 0.0 49.0 ± 0.0 48.3 ± 0.6 49.0 ± 0.0 49.0 ± 0.0 48.0 ± 1.0 63.7c 68.3b 65.4bc 66.2bc 67.5b 73.2a 3.18 3.68 65.4bc 66.7b 61.3c 64.4bc 65.2bc 78.6a 4.14 4.77 11.8b 15.2a 15.5a 15.2a 15.4a 14.6a 3.67 0.96 12.2b 15.2a 15.0a 15.6a 15.2a 14.5a 4.49 1.16 Actual yield (tons/ha) 26,7e 23.2c 21.5d 32,5cd 35,5b 32,2d 35,2bc 34,7bcd 39,9a 4.98 2.95 29.8b 29.4b 30.2d 30.4d 33.3a 28.7b 4.73 2.46 28.0c 28.7bc 28.0c 30.9b 33.7a 30.2bc 5.31 2.70 Note: First crop: Winter - Spring season in 2013 – 2014, second crop: Winter Spring season in 2014 – 2015 - Harvested plants/plot: The number of harvested plants/plot ranges from 47.7 to 49.0 plants/plot, of which Nun variety losses in both seasons , at 47.7 plants/plot in the first crop and 48.3 plants/plot in the second crop (an average of reduction from 0.7-1.3 plants/plot compared to the standard density of 49.0 plants/plot) This is due to the root rot disease, which occurs in both crops at rate of 1.4-2.7% In addition, TN185 (Control) is infected with root rot, rootstalk and bacterial wilt in second crop, so that the number of harvested plants/plot was only 47.7 plants/plot compared to the standard density of 49.0 plants/plot) The remaining varieties have the maximum number of harvested plants/plot compared with the standard density (49 plants/plot), or they slightly decrease (decrease ≤ 0.5 plants/plot) - Number of fruits/plant: All experimental varieties achieve higher number of fruits/plant than control variety (at the lowest significant difference of 95%), from 10.3 to 27.0 fruits/plant in both seasonsx of the Winter – spring season 2013 - 2014 and 2014 - 2015 In which, the highest number of fruits/plant is the hot chilli, with 73.2 fruits per plant in Winter-spring 2013 - 2014 and 78.6 fruits/plant in the Winterspring 2014 - 2015 The number of fruits/plant of the varieties during two crops is not significantly different, ranging from 0.6 to 5.4 fruits/plant - Average weight of fruit: The fruit weight of all varieties in both Winter-spring crop 2013 - 2014 and Winter-spring crop 2014 - 2015 ranges from 11.8 to 15.6 grams In particular, the lowest value is in the Super 20, which is only 11.8 - 12.2 grams, and it is significantly (at the LSD0,05) lower than the control varieties and other varieties The average fruit weight of remaining varieties ranges from 14.5 to 15.6 grams, which is equivalent to the control - Potential yield: The potential yield ranges from 26.7 to 39.9 tons/ha, in which experimental varieties are significantly (at the LSD0,05) higher than the control 13 varieties Among the experimental varieties in both Winter-Spring 2013- 2014 and Winter-Spring 2014- 2015, the highest potential yield is Hot Chilli, from 37.4 to 39.9 tons/ha, higher than the control TN185 from 9.8 to 13.2 tons/ha and the other varieties from 1.0 to 7.4 tons/ha at the LSD0,05 In addition, the potential yield among varieties in different seasons also has differences but not large, ranges from 0.5 to 3.3 tons per hectare - Actual yield: The actual yield ranges from 21.5 to 33.7 tons/ha, similar to potential yield, all experimental varieties are significantly (at the LSD0,05) higher than the control varieties However, different from potential yield, the highest yield is Solar 135, from 33.3 to 33.7 tons/ha in both Winter-spring 2013 - 2014 and Winter-spring 2014 - 2015, which is higher than the control from 10.2 to 12.3 tons/ha and other varieties from 2.9 to 5.8 tons/ha at the LSD0,05, respectively In addition, the actual yield among varieties in different seasons also has differences but not large, ranges from 0.4 to 2.2 tons/ha 3.2.2.4 Status of pests and diseases of hot chilli varieties The results of monitoring of pests and diseases of hot chilli show that: - Status of pests: In both seasons, varieties were infected with mild light at medium level (grade 1-2) Similarly with fruit borers, the varieties were affected from 2.6 to 5.7% in both seasons, the heaviest affected level is in TN 185 (Control) which ranged from - 5.7%, the lowest affected level is in Solar 135, from 2.6 to 3.2% - Status of diseases: All varieties were affected by anthracnose, with the affected percentage from 2.7 to 6.4%, of which the most susceptible one was the control TN 185, its infection was from 5.4 to 6,4% while the lowest affected variety is Solar 135, from 2.7 to 3.1% For root rot, there were only affected varieties: Hot chilli with 2.0% of the total number of damaged plant in the Winter-spring crop of 2014 – 2015; Nun variety was affected in both seasons, at 1.4 - 2.7% and the control variety (1.4%) in the Winter-spring crop of 2014 - 2015 The bacterial wilt disease was appeared only in TN185 variety (control) at a rate of 1.4% in the Winter-spring crop of 2014 - 2015, the remaining varieties were not infected In summary, based on the evaluation of six potential varieties (Super 20, TN356, Nun, Koregon, Solar 135 and Hot chilli) during two crop seasons of Winter spring 2013 - 2014 and Winter - spring 2014 -2015, the Solar135 reveals as a promissing variety which has good characteristics such as concentrating ripening, color of fruit before ripening is dark green and turning to dark red at ripening;the shape of fruit in longitudinal section is narrow triangular; the fruit is long, straight and balanced; with slight spicy The productivity is over 30 tons in all testing crop seasons (from 33.3 to 33.7 tons/ha) It has good resistance to major pests such as thrips, fruit borer, anthracnose, root rot, and bacterial wilt 3.3 Determine the appropriate dosage and ratio of nitrogen, potassium and calcium for hot chilli in Orthic Acrisols soil in Binh Dinh province 3.3.1 Study the effects of dose and ratio of nitrogen and potassium on growth and yield of hot chilli 3.3.1.1 The growth time of Solar 135 variety on various nitrogen and potassium fertilizers in Binh Dinh province 14 In the treatment of 360 kg N/ha, the time from transplanting to flowering, to first harvest and to the end of harvest averages of 36.3 days, 97.2 days and 141.7 days respectively Reduction of nitrogen fertilizer to 200 kg N/ha, the time from transplanting to flowering, to first harvest and to the end of harvest is shorten down correspondingly to 35.0 days, 95.5 days, 139.0 days, respectively (it is 1.3 days, 1.7 days and 2.7 days respectively shorter than the application rate of 360 kg N/ha) and the shortest result is in application of 150 kg N/ha, at 33.7 days from transplanting to flowers; 94.3 days to the first harvest and 135.2 days to the last harvest (that is 2.7 days, 2.9 days and 6.5 days respectively shorter than the application rate of 360 kg N/ha) By contrast, different treatments of potassium fertilizer not show differences in the growth duration of chili (they vary from 0.6-1.4 days in the same crop season) The time from transplanting to flowering at levels of potassium fertilizer ranges from 34.0 to 35.0 days (crop 1) and from 35.3 to 36.0 days (crop 2), time from transplanting to the first harvest varies from 94.7 to 95.3 days (crop 1) and from 96.0 to 96.7 days (crop 2), time from transplanting to end of harvest ranges from 137.3 to 138.7 days (crop 1) and from 138.7 to 140.0 days (crop 2) 3.3.1.2 Growth potential of the Solar 135 variety on various nitrogen and potassium fertilizers in Binh Dinh The average of plant height of the treatment of 360 kg N/ha is 92.2 cm (91.4 – 92.9 cm) which is 4.3% higher than the treatment of 200 kg N/ha (average of 88.2 cm and ranges from 87.3 to 89.0 cm) and 6.6% higher than those of 150 kg N/ha (average of 86.1 cm and ranges from 85.7 to 86.5 cm) By contrast, among different potassium treatments, the plant height is not show the difference The average of canopy diameter in treatment of 360 kg N/ha of two crops is 76.8 cm which is 5,2% higher than treatment of 200kg N/ha (average of crops is 72.2 cm), and 6,7% higher than treatment of 150 kg N/ha ( average of crops is 72,4 cm).At the same time, the stem diameter of the the treatment of 360 kg N/ha is 1.72 cm which is 6.4%, higher than the average of crops of treatment of 200 kg N/ha (average of crops is 1,61 cm),and 6.7% higher than treatment of 150 kg N/ha (average for crops is 1.60cm) 3.3.1.3 Status of pests and diseases of Solar 135 variety on different nitrogen and potassium fertilizers in Binh Dinh province In the different fertilizer formulas, Solar 135 variety was infected with thrips at rate from level to level 2, fruit borer from 2.5% to 7.3%, anthracnose from 5.1% to 13.2%, root rot from 0.7% to 5.4% and bacterial wilt disease from to 2.7% For potassium fertilizers, different rate treatments show no difference or insignificant difference in the incidence of pests and diseases of Solar 135 variety However, for nitrogen fertilizers, the severity of infestation is the highest at rate of 360 kg N/ha and subsequently, it decreases with lesser rates of 200 and 150 kg N/ha At rate of 360 kg N/ha, presence of thrips reaches level This value decreases to level when amount of applied N is reduced to 200 and 150kg N/ha Similarly, at application rate of 360 kg N/ha, fruit borer and anthracnose, root rot and green bacterial wilt infect plants at rate of 6.3% (ranges from 5.4 to7.3%), 13,0% (ranges from 11.7% to 13.7%), 4.9% (ranges from 4.1% to 5.4%) and 1.9% (ranges from 1.4 to 2.7%), respectively At the application rate of 200 kg N/ha, the infection rate of pests and 15 diseases is reduced to 4.2% (fruit borer), 8.8% (anthracnose), 2.6% (root rot) and 0.2% (green bacterial wilt),respectively The smallest rate of pests and diseases infection is in treatment of 150 kg N/ha, at 3.0%, 5.5%, 1.5% and 0.2% respectively 3.3.1.4 Components of yield of Solar 135 variety on different rates of nitrogen and potassium fertilizers in Binh Dinh province The number of fruits/plant among different fertilizer treatments varies from 61.3 to 68.2 fruits /plant For nitrogen fertilizer, the treatment of 360 kg N/ha has the average number of fruits/plant of 64.0 fruits, while the treatments of 200 kg N/ha and 150 kg N/ha achieve 65.3 fruits and 66.8 fruits/plant, respectivly Thus, when nitrogen fertilizer increases from 150kg to 200kg and 360 kg N/ha, the number of fruits/plant does not increase but inversely it tends to decrease In contrast, for potassium fertilizer, application at 350 kg K2O/ha, the average fruits/plant reaches 67.0 fruits, and this number again falls down to 65.0 fruits/plant and 64.2 fruits/plant when potassium is applied at rate of 200 kg K2O/ha and 150 kg K2O/ha, respectively The average fruit weight, fruit length, fruit diameter and pulp thickness not differ significantly among treatments It can be attributed to the application of 150 kg N/ha and 150 kg K2O/ha that are enough amount for the requirement of nitrogen and potassium fro hot chilli grown on Orthic Acrisols soil in Binh Dinh province Hence, there is no significant difference between application of 200 and 360 kg N/ha as well as the application rate of 200 and 350kg K2O/ha The difference in yield components in the experiment is mainly influenced by the number of plants/plot and the number of fruits/plant In terms of balanced ratio between nitrogen and potassium, four treatments such as N3K1, N3K2, N3K3 and N2K1 have the highest number of fruits/plant in the experiment which ranges from 65.8 to 68.2 fruits Remaining treatments range from 61.3 to 65.2 fruits/plant 3.3.1.5 Yield and economic efficiency of Solar 135 variety on different rates of nitrogen and potassium fertilizers in Binh Dinh province Table 3.22 Influence of nitrogen and potassium rates on yield of Solar 135 variety in Winter-spring 2015 - 2016 and Winter-spring 2016 - 2017 in Phu My district, Binh Dinh province Yield of Winter-spring 2015-2016 (tons/ha) Type and amount of Average yield K1 K2 K3 fertilizer based on N N1 32.2 ab 31.8 ab 30.6 b 31.5 b N2 33.9 a 33.0 a 32.7 ab 33.2 a N3 33.3 a 32.7 ab 33.1 a 33.0 a Average yield based on 33.1 a 32.5 a 32.1 a Potassium CV (%) (Plot*N*K) 4.2 Yield of Winter-spring 2016-2017 (tons/ha) Average yield Type and amount of K1 K2 K3 16 fertilizer N1 N2 N3 Average yield based on Potassium based on N 31.8 b 33.9 a 33.5 a ote s: N1 = 36 33.8 a 33.0 a 32.3 a CV (%) (Plot*N*K) 5.7 kg N/ha; N2 = 200 kg N/ha; N3 = 150 kg N/ha; K1= 350 kg K2O/ha; K2 = 200 kg K2O/ha; K3 = 150 kg K2O/ha 32.8 ab 34.5 a 34.2 a 31.6 ab 33.9 ab 33.6 ab 31.1 b 33.2 ab 32.7 ab Results obtained in Table 3.22 show that, in the Winter-spring crop of 2015 2016 and 2016 - 2017, treatment using 360 kg N/ha application rate obtains the yield of hot chili at 31.5 tons/ha and 31.8 tons/ha respectively At the rate of 200 kg N/ha, hot chili yield is 33.2 tons/ha and 33.9 tons/ha respectively At the rate of 150 kg N/ha, yield is 33.0 tons/ha and 33.5 tons/ha, respectively In the above three application rates, 200 and 150 kg N/ha have higher yield, and there is a statistically significant at the LSD0,05 in compare with application rate of 360 kg N/ha in both two crop seasons By contrast, for Potassium fertilizer, due to there is no difference in the yield components (except for fruits/plant), the yield of hot chili in both crops at levels of potassium (350, 200, 150 kg K2O/ha) is not statistically different Table 3.23 Yield of Solar 135 variety in different rates of nitrogen and potassium fertilizers in the Winter-spring crop of 2015 - 2016 and the Winterspring 2016 - 2017 in Phu My district, Binh Dinh province Treatment N1K1 (Control) N1K2 N1K3 N2K1 N2K2 N2K3 N3K1 N3K2 N3K3 Yield (tons/ha) WinterWinterspring 2015 - spring 2016 2016 2017 32.2 ab 32.8 ab 31.8 ab 31.6 ab 30.6 b 31.1 b 33.9 a 34.5 a 33.0 a 33.9 ab 32.7 ab 33.2 ab 33.3 a 34.2 a 32.7 ab 33.6 ab 33.1 a 32.7 ab Average 32.5 31.7 30.9 34.1 33.5 33.0 33.8 33.2 32.9 CV (%) (Plot*N*K) 4.2 5.7 4.2 LSD0.05 (Same nitrogen rate) 2.42 3.37 2.42 LSD0.05 (Different nitrogen rate) 2.33 2.93 2.33 Notes: N1 = 360 kg N/ha; N2 = 200 kg N/ha; N3 = 150 kg N/ha; K1= 350 kg K2O/ha; K2 = 200 kg K2O/ha; K3 = 150 kg K2O/ha N 17 In terms of balanced ratio between nitrogen and potassium, the average yield in two crops of all treatments varies from 30.9 to 34.1 tons/ha, of which the lowest yield is in the treatment N1K3 which gains only 30.9 tons/ha while the highest yields are in three treatments of N2K1, N2K2 and N3K1 which range from 33.5 to 34.1 tons/ha (Table 3.23) Results of economic analysis of all treatments of nitrogen and potassium fertilizer show that, the average yield of crops of all treatments reaches from 30.9 to 44.1 tons/ha which makes income from 370.20 to409.20 millions VND/ha, net profit from 248.40 to 287.55 millions/ha, and profit rate of investment capital from 2.04 to 2.37 In which, the treatment N2K1 achieves the highest yield and income However, the net profit and profit rate of the investment capital are equal or no significant difference compared to the treatments of N2K2, N2K3, N3K1, N3K2 and N3K3 Thus, application rate of 200 and 150 kg N/ha combined with three levels of potassium as 350, 200 and 150 kg K2O/ha not make any difference in net profit and profit rate Therefore, application of treatment N3K2 or applying nitrogen, potassium and phosphorus fertilizer at rate of 150kg N, 100kg P2O5 and 150 K2O for hectare (at ratio of 1.5 : : 1.5) in combination with the basal fertilizer of 20 tons manure plus 500kg lime powder is the reasonable level of fertilizers to produce the highest productivity and economic efficiency of hot chilli grown on Orthic Acrisols soil in Binh Dinh province 3.3.2 Study the effects of dose and ratio of nitrogen and calcium on growth and yield of hot chilli 3.3.2.1 The growth duration of Solar 135 variety on various rates of nitrogen and calcium fertilizers in Binh Dinh province Among the different nitrogen and fertilizer treatments, there is a difference in the growth duration of hot chilli In the treatment of 360 kg N/ha with the time from transplanting to flowering;to first harvest and to the end of harvest average of 36,2 days; 99,9 days and 143 days respectively (varying from 35 to 38 days, 98 to 101 days and 142 to 146 days) When nitrogen fertilizer is reduced to 200 kg N/ha, the time from transplanting to flowering; first harvest and to the end of harvest is 34.0 days; 95.4 days; and138.5 days, respectively (it is 2.2 days, 4.5 days and 4.8 days respectively shorter than that of 360 kg N/ha) and the shortest duration when application of 150 kg N / to 33.5 days to flowers; 93.2 days to the first harvest and 135.0 days to the end of harvest (it is 2.7 days, 6.7 days and 8.3 days respectively shorter than those of application rate of 360 kg N/ha) This result is similar to the experiment of nitrogen and potassium when reducing nitrogen rate from 360 kg N/ha to 200 kg N/ha and 150 kg N/ha By contrast, among different treatments of calcium fertilizer, the growth duration of chilli is less different (it varies from 0.6 - 1.4 days in the same season) The time from transplanting to flowering at rates of calcium fertilizer ranges from 33.3 to 34.3 days (crop 1) and from 34.7 to 36.0 days (crop 2); time from transplanting to the first harvest varies from 94.7 to 96.0 days (crop 1) and from 96.0 - 98.0 days (crop 2); from transplanting to end of harvest is from 137.7 to 138.3 days (crop 1) and 139.3 days to 140.7 days (crop 2) 18 3.3.2.2 Growth potential of the Solar 135 variety on various rates of nitrogen and calcium fertilizers in Binh Dinh The results of monitoring growth of Solar 135 variety in fertilizer treatments in two crop seasons Winter-spring 2015 -2016 and Winter-spring 2016-2017 indicate that, the plant height in the treatment of 360 kg N/ha is 92.3 cm (varies from 91.1 to 93.6 cm), it is 3.0% higher than that of the 200 kg N/ha (average of 89.6 cm and ranges from 88.0 to 91.3 cm) and it is 6.6% higher than that of 150 kg N/ha (average of 86.3 cm and ranges from 85.0 to 88.0 cm) By contrast, among different calcium treatments, plant height does not show the difference The same as plant height, the canopy diameter and stem diameter are different among treatments Canopy diameter in treatment of 360 kg N/ha achieves in average of 77,6 cm during two seasons, it is 5,2% and 6,7% higher than treatment of 200kg N/ha (Average of crop is 73,6 cm) and 150 kg N/ha (average of two crop 72,4 cm) respectively At the same time, the stem diameter of the treatment of 360 kg N/ha is 1.74 cm higher than the average of crops, higher than the 200 kg N/ha treatment (average of crops was 1,62 cm) is 6%, and for treatment of 150 kg N/ha (average for crops was 1.61cm) is 7.5% 3.3.2.3 Status of pests and diseases of Solar 135 variety on different nitrogen and calcium fertilizer in Binh Dinh province The results of monitoring pests and diseases in treatments using different nitrogen and calcium fertilizer in two crops have shown that: Solar 135 variety is infected with peak fruit rot disease from 2.2 to 6.1%, anthracnose from 4.8 - 13.7%, root rot from 0.0 - 6.1% and bacterial wilt from to 3.4% For nitrogen fertilizers, the severity of infestation is highest when applying 360 kg N/ha and decreased with application of 200 and 150 kg N/ha When applied 360 kg N/ha, peak fruit rot disease, anthracnose, root rot and bacterial wilt had moderate infection of 5.4% (range 4.6-6.1% ), 11.7% (range from 10.8 to 13.7%), 4.2% (range from 2.7 to 6.1%) and 1.9% (range from 0.7- 3.4%) However, at the rate of 200 kg N/ha, the disease rate dropped to 3.5% (peak fruit rot), 8.9% (anthracnose), 1.2% (root rot) and 0.7% (green bacterial wilt) and the smallest infection was 150 kg N/ha, the rate of harmful disease was 2.7%; 5.7%; 0.7% and 0.2% For calcium, the rate of disease has decreased significantly when applied from 350 kg CaO/ha to 500 kg CaO/ha Average fruit rot disease decreased from 4.3% to 3.8%, the average anthracnose from 9.8% decreased to 8.3%, the average of root rot disease decreased from 2.8% to 1.8% and average bacterial wilt decreased from 1.6% to 0.7% However, when increase application rate to 800 kg CaO/ha, the rate of disease did not decrease compared to the level of 500 kg CaO/ha 3.3.2.4 Components of yield of Solar 135 variety on different nitrogen and calcium fertilizers in Binh Dinh province The results show that the number of fruits/plant between the different fertilizer treatments varies from 61.7 to 69.3 fruits/ plant For nitrogen fertilizer, the treatment of 360 kg N/ha had the average number of fruit/plant of 63.9 fruits, while the treatment of 200 kg N/ reaches 64.9 fruits, while apply 150 kg N/ ha, all treatments have the average number of fruits/plant is 67.2 fruits Thus, when 19 nitrogen fertilizer increases from 150 to 200 and 360 kg N/ha, the number of fruits/plant not increase but also tend to decrease In contrast, for calcium fertilizer, when applied at 350 kg CaO/ ha, the average fruits/plant reaches 63.8 fruits, and the figure increases to 65.6 fruits/plant when applied 500 kg CaO/ha, and 66.7 fruits/plant when applying 800 kg CaO/ha The average fruit weight, fruit length, fruit diameter and pulp thickness not differ significantly between treatments It can be attributed to the application of 150 kg N/ha to meet the nitrogen requirement of hot chilli in Orthic Acrisols soil in Binh Dinh province, so there is no significant difference compared to the application of 200 and 360 kg N/ha However, different treatments of calcium give a significant difference in application of 500 and 800 kg CaO/ha for average fruit weight, fruit length and fruit diameter compared to 350 kg CaO/ha from 0.6 to 0.9 grams/fruit, 0.3 to 0.6 cm and 0.5 to 1.0 mm Thus, in terms of the difference in the yield components in this experiment, in addition to the main effect of the number of plants/plot and the number of fruits/plant which is also influenced by the calcium factor affecting the mass index average fruit weight, fruit length and fruit diameter At the same time, the N3C2 and N3C3 treatments have the highest number of fruits/plant in this experiment and ranges from 66.9 to 69.0 fruits, the remaining treatment had 62.3 - 66.2 fruits/plant 3.3.2.5 Yield and economic efficiency of Solar 135 variety on different nitrogen and calcium fertilizers in Binh Dinh province Table 3.30 Influence of nitrogen and calcium fertilizers on yield of Solar 135 variety in Winter-spring 2015 - 2016 and Winter-spring 2016 - 2017 in Phu My district, Binh Dinh province Yield on Winter-spring 2015-2016 (tons/ha) Type and amount of Average yield based on C1 C2 C3 fertilizer N N1 28.9 c 31.3 bc 32.0 ab 30.7 b N2 32.2 ab 34.5 a 34.3 a 33.7 a N3 32.2 ab 33.9 ab 34.4 a 33.5 a Average yield based on 31.1 b 33.2 a 33.6 a Calcium CV (%) (Plot*N*C) 4.2 Yield on Winter-spring 2016-2017 (tons/ha) Type and amount of Average yield based on C1 C2 C3 fertilizer N N1 28.2 d 30.5 c 31.3 bc 30.0 b N2 32.0 bc 34.3 a 33.8 a 33.4 a N3 31.4 c 33.6 ab 34.1 a 33.0 a Average yield based on 30.5 b 32.8 a 33.1 a Calcium CV (%) (Plot*N*C) 2.9 20 Notes: N1 = 360 kg N/ha; N2 = 200 kg N/ha; N3 = 150 kg N/ha; C1= 350 kg CaO/ha; C2= 500 kg CaO/ha; C3= 800 kg CaO/ha Results obtained in Table 3.30 show that in the Winter-spring crop of 2015 2016 and 2016 - 2017, treatment using 360 kg N/ha has the yield of hot chilli at 30.7 tons/ha and 30.0 tons/ha respectively At the rate of 200 kg N/ha, hot chilli yield gains 33.7 tons/ha and 33.4 tons/ha respectively At the rate of 150 kg N/ha, yield is 33.5 tons/ha and 33.0 tons/ha, respectively In the above three application rates, application rates of 200 and 150 kg N/ha have higher yield, and there is a statistically significant at the LSD0,05 in compare with application rate of 360 kg N/ha in both two seasons For calcium fertilizer, the application of 500 and 800 kg CaO/ha have higher yield, from 2.1 - 2.5 tons/ha compared to the level of 350 kg CaO/ha and there is a statistically significant at the LSD0,05 in both two seasons Table 3.31 Yield of Solar 135 variety in different nitrogen and calcium fertilizers in the Winter-spring crop of 2015 - 2016 and the Winter-spring 2016 2017 in Phu My district, Binh Dinh province Treatment N1C1 (Control) N1C2 N1C3 N2C1 N2C2 N2C3 N3C1 N3C2 N3C3 Yield (tons/ha) Winter-spring Winter-spring 2015 - 2016 2016 - 2017 28.9 c 28.2 d 31.3 bc 30.5 c 32.0 ab 31.3 bc 32.2 ab 32.0 bc 34.5 a 34.3 a 34.3 a 33.8 a 32.2 ab 31.4 c 33.9 ab 33.6 ab 34.4 a 34.1 a Average 28.6 30.9 31.7 32.1 34.4 34.1 31.8 33.8 34.3 CV (%) (Plot*N*C) 4.2 2.9 LSD0.05 (Same Nitrogen rate) 2.42 1.64 LSD0.05 (Different Nitrogen rate) 2.95 2.24 Notes: N1 = 360 kg N/ha; N2 = 200 kg N/ha; N3 = 150 kg N/ha; C1= 350 kg CaO/ha; C2= 500 kg CaO/ha; C3= 800 kg CaO/ha In terms of interaction between nitrogen and calcium, the average yield in the two crops of all treatments is from 28.6 to 34.4 tons/ha, of which, the lowest is the treatment N1C1 which reaches only 28.6 tons/ha, the highest values are in four treatments N2C2, N2C3, N3C2 and N3C3 which reaches 33.8 - 34.4 tons/ha (Table 3.31) Results of economic analysis of all treatments of nitrogen and calcium fertilizer showd that the average yield of crops of all treatments reaches 28.6 - 34.4 tons/ha which has income from 342.60 - 412.80 millions VND/ha, net profit from 220.87 to 294.32 millions/ha and the profit rate on investment capital varies from 1.81 to 2.49 21 In which, the two treatments N2C2 and N3C3 achieve the highest yield and income However, the net profit and profit rate on the capital investment are equal or no significant difference compared to the N2C3 and N3C2 treatments Thus, with the application rate of 200 and 150 kg N/ha combined with two levels of calcium 500 and 800 kg CaO/ha, there is no difference in net profit and profit rate Therefore, treatment N3C2 or application of nitrogen and calcium with at rate of 150kg N and 500kg CaO for hectare, with basal fertilizer as 20 tons manure, 100 kg P2O5 and 160 kg K2O is the suitable level of fertilizer which achieves the highest productivity and economic efficiency for hot chilli in Orthic Acrisols soil at pHkcl 2.0 mm, average fruit weight of 15 grams, fruit colour is dark green when young, dark red when ripen, light spicy therefore it is satisfied exported standards The number of fruits/plant is 65 – 67 fruits, the average yield is 33.5 tons/ha which is 50.3% higher than TN 185 variety It has good resistance to major pests such as thrips, fruit borer, anthracnose, root rot, and bacterial wilt 1.3 The appropriate application rates of nitrogen, potassium and calcium for hot chilli on Orthic Acrisols soil in Binh Dinh are 150 kg N/ha, 150 kg K2O/ha and 500 kg CaO/ha The ratio of N:P2O5:K2O is 1.5:1.0:1.5 With a basal fertilizer is 20 tons of manure + 150 kg N + 100 kg P2O5 + 150 kg K2O + 500 kg CaO, the yield of Solar 135 variety ranges from 32.9 to 33.7 tons/ha, its net profit ranges from 270.0 to 280.0 millions VND/ and its profit margin is from 2.37 to 2.45 1.4 Grafted plants from the combination of the scion from Solar 135 variety on Trang Khanh Hoa rootstock produces the highest yield of 33.7 tons/ha Although, the yield equivalent to non-grafted control but It has good resistance to bacterial wilt disease (Ralstonia solanacearum) 1.5 Application of the all combination of prospective technical methods which are determined on the Orthic Acrisols soil in Binh Dinh province resulted in increasing productivity by 21.6% (from 25.7 tons/ha to 32.8 tons/ha); net profit from 201.8 millions VND to 278.7 millions VND and profit margin from 1.60 to 2.40 in compare with traditional cultivation practices Recommendations 2.1 To nntroduce Solar 135 variety in Binh Dinh province and application of integrated cultivation techniques that have been identified for hot chilli 2.2 To Continue to collect and study on rootstock selection However, it is important to evaluate their disease resistance to root rot, and bacterial wilt under artificial infiltration conditions, as well as continue to analyze the economic, social and environmental effects of grafting method to make a foundation for completion of the grafting process and cultivation of grafted plants From the collected data, evaluation and exploitation of the good characteristics of the resistant (disease, drought, heat) and quality characteristics(spiciness, fruit color) of chilli varieties to support the breeding of hybrid hot chilli in the future 25 PUBLISHED SCIENTIFIC WORKS RELATED TO THE THESIS Vu Van Khue (2016), “Assessment of hot pepper production stutus in Binh Dinh province”, Journal of Vietnam Agricultural Science and Technology, 11 (72), p 2530 Vu Van Khue (2016), “The result of the selection hot pepper variety (Capsicum annuum L.) in Binh Dinh province”, Science and Technology Journal of Agricultural and Rural Development, 12, p 145-150 Vu Van Khue, Hoang Minh Tam (2018), “Effects of quantity and rate of nitrogen and potassium fertilizers on growth, development and yield of the hot chilli variety Solar 135 (Capsicum annuum L.) on ancient alluvial grey soil in Binh Dinh province”, Journal of Vietnam Agricultural Science and Technology, (89), p 58 65.ĐẾN LU ... yield of the hot chilli variety Solar 135 (Capsicum annuum L. ) on ancient alluvial grey soil in Binh Dinh province”, Journal of Vietnam Agricultural Science and Technology, (8 9), p 58 65.ĐẾN LU... Criteria Total cost (1,000 VND) Materials, power (1,000 Dong) Labor cost (1,000 Dong) Total revenue (million VND) Yield (ton/ha) Product price (1,000 Dong/kg) Net profit (million VND) Rate of return... control The other varieties are PP9955-15 (47.0 plants/plot), Bom Hue (45 plants/plot), Xiem hybrid (44.0 plants/plot), particularly, VRQ3 decreases significantly (41.0 plants/plot) This decline