MINISTRY OF EDUCATION AND TRAINING MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT VIETNAMESE ACADEMY OF FOREST SCIENCES ***** HA VAN NAM STUDY ON SUPPLEMENTING SOME BIOLOGICAL CHARACTERISTICS, PROPAGAT[.]
MINISTRY OF EDUCATION AND TRAINING MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT VIETNAMESE ACADEMY OF FOREST SCIENCES ***** HA VAN NAM STUDY ON SUPPLEMENTING SOME BIOLOGICAL CHARACTERISTICS, PROPAGATION AND PLANTING TECHNIQUES OF Dendrocalamus velutinus N.-H Xia, V T Nguyen & V D Vu IN HANOI Major: Silviculture Code: 62 02 05 SUMMARY OF FORESTRY PHD DISSERTATION SCIENTIFIC SUPERVISOR: Dr Le Van Thanh Assoc Prof, Dr Hoang Van Thang This work has been completed at the Vietnamese Academy of Forest Sciences HANOI, 2023 PUBLISHED WORKS RELATED TO THE THESIS Ha Van Nam, Le Van Thanh (2017), “The influence of potting mixture and the season to the rooting ability of air-layering stems of Dendrocalamus velutinus”, Journal of Agriculture & Rural Development, (8), pp 138-142 Ha Van Nam, Nguyen Thi Trinh, Nguyen Trong Nghia, Nguyen Thi Minh Phuong (2022), “Identification of some mechanical, physical properties and chemical composition of the stem of Dendrocalamus velutinus”, Journal of Agriculture & Rural Development, (18), pp 84-90 INTRODUCTION Background and rationale Dendrocalamus velutinus (D velutinus), a species of bamboo, is grown in Vietnam under the genus Dendrocalamus The plant has large dimensions, thick, hard and durable culm walls, and the ability to provide raw materials for high-end processing industries Its edible shoots are sweet with a slight bitterness The price of fresh shoots in Ba Vi - Hanoi fluctuates between 8,000 - 15,000 VND/kg, while dried shoots cost between 300,000 - 350,000 VND/kg However, due to limited supply and high demand, the product is not sufficient for the market The culms are harvested and used for household items, poles, and other woven and processed products, with an average selling price of 50,000 VND/culm in Hanoi and Hoa Binh D velutinus has been grown in some provinces such as Hanoi, Hoa Binh, and Phu Tho However, the bamboo business still relies on traditional methods with inadequate planting and tending techniques, resulting in low yield of shoots and culms Research on D velutinus is still lacking, particularly in the study of its biological characteristics, propagation methods, and planting techniques Therefore, the thesis "Study on supplementing some biological characteristics, propagation and planting techniques of Dendrocalamus velutinus N.-H Xia, V T Nguyen & V D Vu in Hanoi" is necessary, with significance in both scientific and practical production aspects of cultivating shoots and culms Objectives of the thesis 2.1 Theoretical goal To supplement scientific bases for developing interperiodping plantations of D velutinus for shoots and culms, contributing to improving the yield and quality of D velutinus in Hanoi 2.2 Practical objectives - To identify some biological characteristics of D velutinus - To determine some propagation techniques for planting D velutinus, providing a basis for proposing solutions for developing this plant species in the research area and other similar locations Scientific and practical significance of the thesis 3.1 Scientific significance The thesis provides scientific data on the biological characteristics and propagation techniques for planting D velutinus 3.2 Practical significance The thesis proposes propagation techniques for planting D velutinus in Hanoi Novel contributions - The thesis supplements some biological characteristics of D velutinus, such as its ability to accumulate mineral nutrients, carbon, physical and chemical properties of culms and shoots, in some areas where D velutinus is grown - The thesis supplements some propagation and planting techniques for D velutinus in Hanoi, including the effects of the season and medium mixture on air-layering, the effects of the season and rooting medium of cuttings on rooting rate, and the effects of water, fertilizers and soil mounding techniques on shoot yield Object and scope 5.1 Object: D velutinus 5.2 Scope - Study area: + Additional biological characteristics of Bong moc bamboo are studied at locations: Soc Son, Ba Vi - Hanoi; Luong Son, Mai Chau, Hoa Binh are areas where D velutinus is currently present + Technical research on propagation and planting techniques of D velutinus is conducted in Soc Son, Hanoi - Content: + Study on biological characteristics: Focus on clarifying some characteristics of distribution, ecology, growth, mineral nutrient accumulation capacity, carbon sequestration capacity, phenological characteristics, physical and mechanical properties of culms, chemical composition of the culms and shoots + Study on propagation: Propagation by air-layering and cutting in Soc Son - Hanoi + Study on planting techniques: The effects of water, fertilizers, and root mulching materials on a new planting model The number of retained parent culms left behind, and the technique of shoot mulching on a D velutinus planting model for years in Hanoi Thesis structure The thesis consists of 116 pages, structured into sections: Introduction (4 pages); Chapter 1: Overview of research issues (23 pages); Chapter 2: Research content and methods (23 pages); Chapter 3: Research results and discussion (67 pages); Conclusion, limitations, and recommendations (3 pages) CHAPTER OVERVIEW OF RESEARCH PROBLEMS 1.1 Worldwide The genus Dendrocalamus has about 60 species (Ohrnberger, 1999), (Yi et al, 2008), (Guo et al, 2010), widely distributed in tropical and subtropical regions of Asia (Srapleton, 1994), (Dransfied and Widjaja, 1995), at elevations from a few tens of meters to 1,700 meters above sea level Many authors have studied bamboo propagation using various methods such as seeds, air-layering, tissue culture, root sprouts, and cutting, with authors such as Banik, 1985; Hassan, 1977; A.N Rao and V Ramanatha, 2000; Victor Cusack, 1997; China Bamboo Research Center, 2001 Rao A.N and Ramanatha Rao V (1999) studied soil conditions and found that bamboo is often suitable in well-drained areas with sandy loam, clay loam with high nutrient content, flat terrain, or low-sloping hills Fu Maoyi, Xiao Jianghua (1996) identified factors affecting the process of shoot production, growth, and development of bamboo, including soil moisture, temperature, nutrients, forest structure, forestry measures, pests, and diseases The China Bamboo Research Center (2008) recommends fertilizing 13 times a year to increase shoot production The first fertilization in March combines 750-900kg/ha urea and mixed fertilizers The second fertilization in August applies urea or mixed fertilizers at 0.5-1kg/plant The third fertilization in December is mainly organic fertilizer at 50kg/plant Prosea (1995) recommends applying 20-25kg of organic fertilizer per clump before the growing season, and chemical fertilizers four times a year, each time applying 80kg NPK per hectare at a ratio of 40:10:30 and 0.65 Si 1.2 In Vietnam Camus & A Camus (1932) reported that there were species of Dendrocalamus in Vietnam By 2007, the group of authors Nguyen Hoang Nghia and Tran Van Tien (2007) had identified 21 species in Vietnam Ngo Quang De, Le Xuan Truong (2011) suggested that for some bamboo species like D parvigemmiferus or D membranaceus, stem cutting can be used as a propagation method Ma Thanh Thuyet et al (2020) found that using a potting mix of 68% surface soil + 2% NPK + 30% straw produced the best results in air-layering of D brandisii There have been many studies on bamboo cultivation techniques by authors such as Pham Van Tich (1963), Le Nguyen et al (1971), Le Quang Lien (1990, 2001); Ngo Quang De (1994); Nguyen Truong Thanh (2002); Cao Danh Thinh (2004) Tran Ngoc Hai (2017) reported that the soil under D velutinus forest in Ba Vi has a mechanical composition ranging from light loam to clay loam, with the elevation of 80-689m The author described the morphological and phenological characteristics of the species Le Van Thanh (2013) and Tran Ngoc Hai (2017) studied the cutting and air-layering of D velutinus, using 1-year-old stems gave the highest rooting rate in air-layering In specific, air-layering using 1,500 ppm IBA growth regulator achieved a 100% rooting rate, and stem cutting using 2,000 ppm IBA achieved a 70% rooting rate Nguyen Huy Son and colleagues (2013) suggested that D velutinus can be planted at a density of 100-625 clumps/ha for monoculture, but the common density is 210-330 clumps/ha Le Van Thanh (2013) found that fertilizing with 0.7kg NPK combined with 3kg of microorganisms resulted in better growth than less or none fertilizing Tran Ngoc Hai (2017) recommended a fertilizer dosage of 20-30 kg of compost + 2kg of NPK fertilizer, applied several times a year for D velutinus 1.3 Justification Studies both worldwide and in Vietnam have shown that the genus Dendrocalamus, including D velutinus, has received significant attention from scientists Successful research has been conducted on the morphology, ecology, propagation, and silvicultural techniques such as fertilization However, there are still gaps and incomplete research This thesis aims to address some of these gaps, contribute to the general theoretical foundation, and propose planting techniques for D velutinus to serve the practical development of this species Chapter RESEARCH CONTENTS AND METHODOLOGY 2.1 Research contents 2.1.1 Biological characteristics of D velutinus - Ecological and growth characteristics of D velutinus - Phenological characteristics of D velutinus culm and shoots - Nutrient accumulation capacity of D velutinus - Carbon sequestration capacity of D velutinus 2.1.2 Use-value of D velutinus shoots and culms - Some nutritional components of D velutinus shoots - Some mechanical and physical properties of D velutinus culms - Some chemical components of D velutinus culms 2.1.3 Propagation techniques of D velutinus - Propagation using air-layering method + Effects of seasons on rooting rate of air-layering stems + Effects of rooting hormone mixtures on rooting rate of air-layering stems - Propagation using stem cutting method + Effects of seasons on rooting rate of cuttings + Effects of rooting medium on rooting rate of cuttings 2.1.4 Some planting techniques of D velutinus - Effects of irrigation on growth and development of D velutinus - Effects of root mulching materials for parent culms on the growth and development of D velutinus - Effects of fertilization on the growth and development of D velutinus - Effects of the number of retained parent culms on the ability to produce shoots of D velutinus - Effects of soil mounding on shoot productivity of D velutinus 2.1.5 Proposal of planting techniques for D velutinus 2.2 Methodology 2.2.1 Approach The thesis is implemented with the following approaches: inheritance approach, participatory approach, and systemic approach 2.2.2 Materials Ecological and growth characteristics: stands of D velutinus in Soc Son, Ba Vi - Hanoi, Luong Son, and Mai Chau - Hoa Binh Phenological characteristics: stands of D velutinus in Soc Son, Ba Vi - Hanoi, and Luong Son - Hoa Binh Nutrient accumulation capacity and carbon sequestration capacity: 7year-old stands of D velutinus in Soc Son - Hanoi Nutritional components of D velutinus shoots: samples of shoots of D velutinus, D latiflorus, and Bambusa blumeana in Soc Son - Hanoi Mechanical and physical properties and chemical components of culm of D velutinus: 3-year-old culms in stands of D velutinus in Ba Vi Hanoi Propagation techniques: 6-10-month-old air-layering stems and stem cuttings in stands of D velutinus in Nam Son commune, Soc Son district, Hanoi 2.2.3 Specific research methods 2.2.3.1 Biological characteristics of D velutinus Establishing 18 standard plots of 1,000m2 for D velutinus, classified by different categories of ages and areas, including plots in Soc Son, plots in Ba Vi, plots in Luong Son, and plots in Mai Chau The following parameters were determined in the plots: soil characteristics, absolute elevation, slope, aspect, number of culms in each clump, diameter at 5th node (D5), total height (Hvn), age, and climatic conditions of the survey area - The soil characteristics were determined by digging soil profiles at each location in plots by random sampling Soil samples were taken at two depths, 0-20cm and 21-50cm, and analyzed for various parameters, including bulk density, particle density, texture, pH KCl, organic matter, available nitrogen (N), available phosphorus (P2O5), and available potassium (K2O) - The phenological characteristics of D velutinus were conducted by observation in different stands, including those under 100m in Soc Son Hanoi, between 200-300m and 500-700m in Ba Vi - Hanoi, and 200-300m in Luong Son - Hoa Binh representative clumps of D velutinus were chosen at each stand, with observations made on the vegetative organs during leaf shedding, shoot emergence, branch emergence, and new leaf emergence In addition, observations were also made on the flowering branches, blooming, and fruiting of other D velutinus clumps in each stand - The nutrient accumulation capacity of D velutinus was studied using a standard tree method on the stands in Soc Son in May before the shooting season Tree samples were taken from three different age groups (1, 2, and years old) to cut down then separated into branches, leaves, stem, and roots The samples were then analyzed for various nutrients, including total nitrogen (N), total phosphorus (P2O5), total potassium (K2O), and silicon (SiO2) - The carbon sequestration capacity of D velutinus was determined by analyzing the organic carbon content (%OC) of the trees using the Walkley Black method Samples were partly taken from the same three age groups as in the nutrient accumulation study 2.2.3.2 The use-value of D velutinus shoots and culms - The nutritional components of the shoots representative samples of shoots in standard clumps in the 5-yearold stand of D velutinus were collected together with shoot samples of the other two bamboo varieties (3 samples of each) at the local, D latiflorus and Bambusa blumeana, for comparison The nutritional components analyzed included water content, total sugar, glucose, protein, lipid, and cellulose at the National Center for Food Analysis and Inspection - Institute of Food Industry - The mechanical and physical properties of the culms 3-year-old culms of D velutinus in Ba Vi were selected according to standard tree method then cut down in November for sampling Determination of mechanical and physical properties with a sample size of 60 was carried out at the laboratory of the Forest Industry Research Institute The properties analyzed included volume weight (at 12% moisture content), tangential and radial shrinkage, volumetric shrinkage, compressive strength, and static bending The chemical components of the D velutinus culms were also analyzed using samples taken from the same study site The analysis was performed at the Faculty of Chemical Engineering, Hanoi University of Science and Technology, and included the determination of fiber size, cellulose, lignin, pentosan, ash, extractives in absolute ethanol, alkalisoluble substances (1% NaOH), and water-soluble substances 2.2.3.3 Propagation techniques of D velutinus a) Propagation of D velutinus by air-layering method - The effect of planting time on the rooting rate of air-layering stems of D velutinus + Experiment 1: air-layering in Spring-Summer period (April-May) + Experiment 2: air-layering in Summer-Autumn period (JulyAugust) + Experiment 3: air-layering in Autumn-Winter period (OctoberNovember) + Experiment 4: air-layering in Winter-Spring period (JanuaryFebruary) In all experiments, stems were treated with growth regulator IBA at a concentration of 1,500 ppm by applying it to the branch collars before airlayering - The effect of potting mix on the rooting rate of D velutinus airlayering stems: Arrangement of experiment formulas in April: Formula 1: 68% topsoil + 2% NPK + 30% straws; Formula 2: 68% topsoil + 2% NPK + 20% rice husk + 10% ash; Formula 3: 80% topsoil + 20% compost; Formula 4: 100% topsoil (control) The experimental formulas not use growth regulators * Each experiment is arranged with replications; each replication consists of 30 air-layering stems The observation time is 42 days, until no potted stems produce roots The quality of roots is evaluated at the 42 nd day: the root quality is classified into levels including good, average, and poor (a potted stem is considered to have good root quality if the root system covers ≥1/2 of the pot surface area; the root quality is considered average if the root system covers from 1/3 to