Tree Pruning: the Basics! Pruning Objectives!

Total Page:16

File Type:pdf, Size:1020Kb

Tree Pruning: the Basics! Pruning Objectives! 1/12/15! Tree Pruning: The Basics! Pruning Objectives! Improve Plant Health! Safety! Aesthetics! Bess Bronstein! [email protected] Direct Growth! Pruning Trees Increase Flowers & Fruit! Remember-! Leaf, Bud & Branch Arrangement! ! Plants have a genetically predetermined size. Pruning cant solve all problems. So, plant the right plant in the right way in the right place.! Pruning Trees Pruning Trees 1! 1/12/15! One year old MADCap Horse, Ole!! Stem & Buds! Two years old Three years old Internode Maple! Ash! Horsechestnut! Dogwood! Oleaceae! Node Caprifoliaceae! Most plants found in these genera and families have opposite leaf, bud and branch arrangement.! Pruning Trees Pruning Trees One year old Node & Internode! Stem & Buds! Two years old Three years old Internode Node! • Buds, leaves and branches arise here! Bud scale scars - indicates yearly growth Internode! and tree vigor! • Stem area between Node nodes! Pruning Trees Pruning Trees 2! 1/12/15! One year old Stem & Buds! Two years old Dormant Buds! Three years old Internode Bud scale scars - indicates yearly growth and tree vigor! Node Latent bud - inactive lateral buds at nodes! Latent! Adventitious" Adventitious bud! - found in unexpected areas (roots, stems)! Pruning Trees Pruning Trees One year old Epicormic Growth! Stem & Buds! Two years old Three years old Growth from dormant buds, either latent or adventitious. Internode These branches are weakly attached.! Axillary (lateral) bud - found along branches below tips! Bud scale scars - indicates yearly growth and tree vigor! Node Latent bud - inactive lateral buds at nodes! Adventitious bud! Watersprouts! Suckers! - found in unexpected areas (roots, stems)! Pruning Trees Pruning Trees 3! 1/12/15! One year old Axillary (Lateral) Buds! Stem & Buds! Two years old Three years old Internode Apical (terminal) bud Axillary (lateral) bud - found along branches below tips! Bud scale scars - indicates yearly growth and tree vigor! Node Latent bud - inactive lateral buds at nodes! Adventitious bud! - found in unexpected areas (roots, stems)! Pruning Trees Pruning Trees Apical Dominance! Apical (Terminal) Bud! ! • Found at branch tips! • Contains primary meristem" The apical (terminal) bud contains the apical meristem, which contains plant hormones called auxins that inhibit growth of lateral buds.! Pruning Trees Pruning Trees 4! 1/12/15! When apical dominance is broken by injury (storms, Woody Plant Tissues: Xylem! animals, etc.) or pruning, lateral and dormant buds Heartwood! fight to become the new terminal leader.! Sapwood Heartwood Bark ! Phloem (living) • provides structural Cork backbone! cambium ! Cork Sapwood! ! • conducts water and nutrients from roots throughout the tree! Vascular ! Pruning Trees Pruning Trees cambium Woody Plant Tissues: Vascular Cambium! Woody Plant Tissues: Bark (Inner)! Sapwood Heartwood Bark Phloem (living)! Phloem (living) ! • conducts Cork food from cambium the leaves Cork throughout the plant! ! This is a secondary (lateral) meristem that allows for increase in xylem and phloem tissues, as well as cambium cells. The result is increased stem and trunk diameter.! Vascular Pruning Trees Pruning Trees cambium 5! 1/12/15! Woody Plant Tissues: Bark (Outer)! Annual Growth Rings! Bark Cork! Sapwood Heartwood ! Phloem (living) • protection ! Cork Cork cambium! cambium ! Cork • cambium cells present in some species increase cork ! Earlywood (Springwood)! Latewood (Summerwood)! • First new wood in spring! • Growth later in summer! • Large cells with thin cell walls! • Small cells with thicker cell walls! • Light in color • Dark in color Vascular Pruning Trees cambium Pruning Trees Vascular Rays! Tree Structure Trunk! ! Crown! • leaders! • scaffold branches! • lateral branches! • spur shoots! • twigs! ! Epicormics! • suckers! Vascular rays transport sugars and other compounds • watersprouts! radially through vascular tissues, store starch, and assist in restricting decay in wood tissue.! Pruning Trees Pruning Trees 6! 1/12/15! Tree Form! Branches! Lateral branches! Scaffold branches! Decurrent! Excurrent! Pruning Trees Pruning Trees Branch Wood & Trunk Wood! Branch Wood and Trunk Wood! Photos by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida Pruning Trees Pruning Trees ! 7! 1/12/15! Branch Collar & Branch Bark Ridge! Branch Bark Ridge! Branch collar with no visible branch bark ridge! Branch Collar! Branch Collar! Photo by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida! Photo by Edward F. Gilman, Professor, Environmental Horticulture Pruning Trees Department, IFAS, University of Florida! Pruning Trees Types of Branch Attachments! Codominants & Included Bark! • strong attachments have smaller branches (branch wood) secured in larger branches or trunks (trunk wood)! • trunk wood forms a branch collar around the branch wood, and a branch bark ridge is often visible! • codominant stems are poorly attached! • included bark forms both in codominant and narrow angled attachments! Illustrations by Edward F. Gilman, Professor, Environmental Horticulture Pruning Trees Department, IFAS, University of Florida! Pruning Trees 8! 1/12/15! Acute Angle of Attachment! Branch Protection Zone! • a branch protection zone forms at the base of branches that are small in comparison to the trunk! ! • codominant stems have no branch protection zone! Photos by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida! Illustrations by Edward F. Gilman, Professor, Environmental Horticulture Pruning Trees Pruning Trees Department, IFAS, University of Florida! Codominants with included bark (and decay) ! Included bark due to acute attachment ! Photo by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida! Photo by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida! Pruning Trees Pruning Trees 9! 1/12/15! Pruning Cut: Heading! • localized response! • ‘hydra effect! • leaves stubs! • cut to a node ! !(selective heading)! ! • reduction cut! !(selective heading)! ! • shearing ! !(non-selective heading)! ! • topping! Photo by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida! !(non-selective heading)! Photos by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida! Pruning Trees Pruning Trees Pruning Cut Types Reduction Cut! HEADING CUT ● THINNING CUT ● REDUCTION CUT • localized response! • ‘hydra effect! • leaves stubs Pruning Trees Pruning Trees 10! 1/12/15! Reduction Cut! Reduction Cut! Cut the stem to a If the lateral branch is too lateral branch large small of a diameter, epicormic enough to assume the shoots will develop.! terminal leader role.! ! (at least 1/3 to 1/2 the diameter of the removed stem)! Photos by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida Pruning Trees Pruning Trees ! Pruning Cut Types Pruning Cut Types HEADING CUT ● ReductionTHINNING HEADINGCUT Cut ●! REDUCTION CUT ● THINNING CUT CUT ● REDUCTIONHeading or CUT Reduction Cut?! Heading Reduction Cut here Cut to a node Lateral branch remains Illustrations by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida! Pruning Trees Pruning Trees 11! 1/12/15! Topping! Shearing! • cuts through several years • use on plants with small old wood! leaves that are tough ! enough to take it! • ugly ! ! ! • • some large leaf plants OK! doesn’t work to reduce height; plant responds with ! new, poorly attached stems! • formal look! ! ! • unhealthy; opens tree to • non-selective heading! decay! ! • expensive to maintain! ! Photos by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, Pruning Trees Pruning Trees University of Florida! Pruning Trees Pruning Trees 12! 1/12/15! Thinning! Before & After Thinning! • cut to branchs point of origin! ! • preserves apical dominance! ! • natural look! ! • cut outside of branch collar! Photos by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida! • cut smaller laterals • open and natural off main stems looking Photo by Edward F. Gilman, Professor, Environmental Horticulture Department, Pruning Trees IFAS, University of Florida! Pruning Trees How to Make a Thinning Cut! Cut #2 Cut #3 • cut just outside the branch collar! Cut #1 Branch bark ridge • the branch collar is kept intact! Branch collar Photo by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida! Photo by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, • locate branch collar (use branch bark ridge for guidance)! University of Florida! Pruning Trees Pruning Trees 13! 1/12/15! Callus & Woundwood! Pruning technique: no visible branch collar! symmetrical formation indicates proper cut! Illustrations by Edward F. Gilman, Professor, Environmental Horticulture Department, IFAS, University of Florida! Pruning Trees Pruning Trees CODIT: compartmentalization of decay in trees! • plants can limit, or wall off, decay that sets in after wounding! ! • plants dont HEAL, they chemically SEAL off damage! ! • CODIT works best on young wood (1-3 yrs.)! ! • species vary in successful compartmentalization! ! • 4 walls form to varying degrees of success! asymmetrical formation indicates cut into trunk wood! Pruning Trees Pruning Trees 14! 1/12/15! Wall 2: pre-existing defense
Recommended publications
  • Chapter 6 Care and Handling
    Chapter 6 Care and Handling The following TEKS will be addressed in this chapter: (6) The student knows the management factors of floral enterprises. The student is expected to: (A) use temperature, preservatives, and cutting techniques to increase keeping quality; (B) identify tools, chemicals, and equipment used in floral design; (C) fertilize, prune, and water tropical plants; (D) manage pests; and (E) demonstrate the technical skills for increasing the preservation of cut flowers and foliage. Care and Handling of Cut Flowers and Foliages Cut flowers, even though they have been separated from the parent plant, are living, actively metabolizing plant parts. These parts undergo the same basic aging process as the entire plant — only quicker. However, the rate of deterioration can be slowed down considerably by supplying the cut flower with its basic needs. The first and foremost need of a cut flower is water. Second is food. In addition, certain damaging factors such as exposure to ethylene gas, microbial attack and rough handling must be avoided. From a practical point of view, a controlled rate of opening is needed as well as maintenance of good color. All of these factors must be considered by everyone who handles the product. This includes growers wholesalers and retailers. In order to be competitive in the marketplace our product must be desirable to the consumer. Our flowers must be fresh for the customer to enjoy! Factors Affecting Quality There are several factors which play a part in keeping the quality of cut flowers at a high level: (1) the grower (2) moisture balance.
    [Show full text]
  • Reproduction in Plants Which But, She Has Never Seen the Seeds We Shall Learn in This Chapter
    Reproduction in 12 Plants o produce its kind is a reproduction, new plants are obtained characteristic of all living from seeds. Torganisms. You have already learnt this in Class VI. The production of new individuals from their parents is known as reproduction. But, how do Paheli thought that new plants reproduce? There are different plants always grow from seeds. modes of reproduction in plants which But, she has never seen the seeds we shall learn in this chapter. of sugarcane, potato and rose. She wants to know how these plants 12.1 MODES OF REPRODUCTION reproduce. In Class VI you learnt about different parts of a flowering plant. Try to list the various parts of a plant and write the Asexual reproduction functions of each. Most plants have In asexual reproduction new plants are roots, stems and leaves. These are called obtained without production of seeds. the vegetative parts of a plant. After a certain period of growth, most plants Vegetative propagation bear flowers. You may have seen the It is a type of asexual reproduction in mango trees flowering in spring. It is which new plants are produced from these flowers that give rise to juicy roots, stems, leaves and buds. Since mango fruit we enjoy in summer. We eat reproduction is through the vegetative the fruits and usually discard the seeds. parts of the plant, it is known as Seeds germinate and form new plants. vegetative propagation. So, what is the function of flowers in plants? Flowers perform the function of Activity 12.1 reproduction in plants. Flowers are the Cut a branch of rose or champa with a reproductive parts.
    [Show full text]
  • Protect Oak Tree Seedlings from Browsing Using Paper Bud Caps
    Field Tip #13 May 2013 PROTECT OAK TREE SEEDLINGS FROM BROWSING USING PAPER BUD CAPS By Doug Hecker, Silviculture Program Forester - Sandstone Depredation by deer on planted and natural oak tree seedlings can be a severe problem. Repeated browsing will restrict growth dramatically, creating very deformed seedlings and saplings, repeated dieback and re-sprouting, and even mortality. After many years of effort to control browsing using balloons, tree shelters, repellants, fencing, and dry wall joint tape, a successful technique, using 4” x 4” bud cap paper, was developed to protect hardwood seedlings. Although effective 65 to 75% of the time, balloons can have negative effects on about one-third of the trees, causing dieback on the terminal bud. A lateral bud then takes over as the new terminal bud, sometimes deforming the shape of the tree. Balloons need to be applied only when conditions are Figure 1: 4 x 4 inch piece of bud cap paper dry. If they are applied after a rain or even a heavy morning due, the terminal bud can rot, and die back. Oak should be bud capped in October, after the leaves have started to senesce; at the point where the leaf starts to turn red, before dropping, or easily pulls off without damaging the leaf cuticle or stem of the tree. This period is usually during the first three weeks of October, before the leaves drop. The seedlings can be capped after leaf drop, however it is easier for crews to identify oak seedlings while the leaves are still on. Oaks tend to retain their leaves even after they change color and become dormant.
    [Show full text]
  • CHERRY Training Systems
    PNW 667 CHERRY training systems L. Long, G. Lang, S. Musacchi, M. Whiting A Pacific Northwest Extension Publication OREGON STATE UNIVERSITY n WASHINGTON STATE UNIVERSITY n UNIVERSITY OF IDAHO in cooperation with MICHIGAN STATE UNIVERSITY CHERRY training systems Contents Understanding the Natural Tree....................................................................................................................................................... 3 Training System Options.......................................................................................................................................................................... 4 Rootstock Options.......................................................................................................................................................................................... 5 Pruning and Training Techniques.....................................................................................................................................................5 Kym Green Bush............................................................................................................................................................................................ 10 Spanish Bush.....................................................................................................................................................................................................18 Steep Leader......................................................................................................................................................................................................25
    [Show full text]
  • Dormant Tree (And Shrub) Pruning
    Dormant Tree (and Shrub) Pruning By Sue Gwise, Consumer Horticulture Educator & Master Gardener Coordinator If you need to prune any of your hardwood trees, late winter is the best time for this task. Even fruit trees like apple, pear, and peach should be pruned during the dormant season, which is basically February through early April, and prior to spring bud swell. The worst time to prune hardwood trees is during or soon after their initial growth flush. Unfortunately, this is the same time of year when most people begin their landscape chores. A prune at this point is very stressful to the tree. Dormant pruning is done for several reasons: 1. Fungi and insects are not active, and this eliminates the chance of disease and infestation. 2. Pruning done before bud swell in early spring will maximize growth. 3. It minimizes the chance of cold damage which is higher if pruning is done in early winter. 4. The tree will go into a full season of active growth in which pruning wounds will close-up much quicker. 5. There are no leaves, so it is much easier to see the tree structure. Like anything, there are exceptions. Crabapples, for example, tend to sucker profusely if pruned in the winter or early spring. As a result, species prone to suckering should be pruned in the summer. Things get trickier with ornamental flowering trees and shrubs. In these cases, the timing of pruning relates to the type of wood that develops flowers. In species where blooms occur on the current season’s growth (new wood), a dormant pruning is fine.
    [Show full text]
  • Pruning Manual Arboritecture
    Pub. No. 37 November 2016 Arboritecture:Arboritecture: BuildingBuilding GreatGreat TreesTrees WithWith PruningPruning ○○○○○○○○○○○○○○○○○○○ ○○○○○○○○○○○○○○○○○○○○○ 1234567890123456789012345 1234567890123456789012345 1234567890123456789012345 1234567890123456789012345 1234567890123456789012345 1234567890123456789012345 1234567890123456789012345 1234567890123456789012345 1234567890123456789012345 #1○○○○○○○ 1234567890123456789012345 #1 1234567890123456789012345PC 1234567890123456789012345 1234567890123456789012345 1234567890123456789012345 1234567890123456789012345 1234567890123456789012345DZ 1234567890123456789012345 1234567890123456789012345 #2 1234567890123456789012345 1234567890123456789012345 1234567890123456789012345 1234567890123456789012345 1234567890123456789012345#3 1234567890123456789012345 1234567890123456789012345 STEM by Dr. Kim D. Coder, Professor of Tree Biology & Health Care Warnell School of Forestry & Natural Resources, University of Georgia This manual is a third revision of a popular educational product designed for helping tree health care providers and other allied professionals appreciate and understand a number of basic aspects of young to middle-aged tree pruning. This manual is a synthesis and integration of research and educa- tional concepts regarding trees and how pruning impacts tree biology, struc- ture and aesthetics. This product is for awareness building and educational development. This product does not represent young tree training specifica- tions or pruning standards. At the time it was finished, this publication
    [Show full text]
  • What Makes a Tree
    Trees 101 Structure, Function, Identification, Jargon Pam Zipse Outreach Coordinator, Rutgers Urban Forestry Program of NJAES urbanforestry.rutgers.edu NJ Licensed Tree Expert # 426 NJ Certified Teacher of Biological Science # 863775 Defining a Tree What is a Tree? • A woody perennial plant, typically having a single stem or trunk growing to a considerable height and bearing lateral branches at some distance from the ground. What is a Tree? • A large water pump facilitating moisture exchange for energy conversion and food production. Photosynthesis Photosynthesis • For a tree to be healthy, it must be able to carry out photosynthesis. • Carbon Dioxide + Water in the presence of light , yields Sugar + Oxygen LIGHT CO₂ + H₂O → C₆H₁₂O₆ + O₂ Photosynthesis • So what does a tree need to be able to successfully carry out photosynthesis? • Carbon Dioxide (Air) • Water • Light Photosynthesis • Anything that inhibits a tree’s ability to carry out photosynthesis… • Anything that prevents a tree from pumping water and cycling air… • is going to harm the tree! Forestry is Common Sense Elevated to a Science Structure and Function… Beginners Guide to Tree Anatomy and Physiology Anatomy & Physiology (Structure & Function) • Tree Anatomy deals with the structure of trees. – What are the parts of a tree? • Tree Physiology deals with the functions and activities of these parts. – How does a tree grow? How does a tree grow? How does a tree grow? • Trees grow from the outside out and from the top up. How does a tree grow? • The cambium is the living layer of actively dividing cells located just inside the bark that produces a new growth ring each year.
    [Show full text]
  • Lecture 30 Origins of Horticultural Science
    Lecture 30 1 Lecture 30 Origins of Horticultural Science The origin of horticultural science derives from a confl uence of 3 events: the formation of scientifi c societies in the 17th century, the creation of agricultural and horticultural societies in the 18th century, and the establishment of state-supported agricultural research in the 19th century. Two seminal horticultural societies were involved: The Horticultural Society of London (later the Royal Horticulture Society) founded in 1804 and the Society for Horticultural Science (later the American Society for Horticultural Science) founded in 1903. Three horticulturists can be considered as the Fathers of Horticultural Science: Thomas Andrew Knight, John Lindley, and Liberty Hyde Bailey. Philip Miller (1691–1771) Miller was Gardener to the Worshipful Company of Apothecaries at their Botanic Garden in Chelsea and is known as the most important garden writer of the 18th century. The Gardener’s and Florist’s Diction- ary or a Complete System of Horticulture (1724) was followed by a greatly improved edition entitled, The Gardener’s Dictionary containing the Methods of Cultivating and Improving the Kitchen, Fruit and Flower Garden (1731). This book was translated into Dutch, French, German and became a standard reference for a century in both England and America. In the 7th edition (1759), he adopted the Linnaean system of classifi cation. The edition enlarged by Thomas Martyn (1735–1825), Professor of Botany at Cambridge University, has been considered the largest gardening manual to have ever existed. Miller is credited with introducing about 200 American plants. The 16th edition of one of his books, The Gardeners Kalendar (1775)—reprinted in facsimile edition in 1971 by the National Council of State Garden Clubs—gives direc- tions for gardeners month by month and contains an introduction to the science of botany.
    [Show full text]
  • Pruning the Orchard
    Pruning the Orchard Ronald H. Walser, Wilford A. Wright, Alvin R. Hamson, Extension Horticulturists, Utah State University Revised March 1994 by Dan Drost, Extension Vegetable Specialist, and Tony Hatch, Extension Horticulture Specialist March 1994 HG 363 CONTENTS Introduction ....................................... 1 Pruning Equipment .................................. 1 Apple Trees ....................................... 1 Central Leader Pruning .............................. 2 Modified Leader or Modified Central Leader Pruning ...... 3 Peach and Nectarine ................................. 5 Open Center Pruning ................................ 6 Pear Trees ......................................... 7 Sweet Cherry Trees ................................. 8 Tart Cherry Trees ................................... 8 Plums ............................................ 9 Apricot Trees ...................................... 9 Walnut and Pecan Trees ............................. 10 Espalier .......................................... 10 Pruning Neglected Trees ............................ 11 Grapes .......................................... 12 Raspberries ....................................... 13 Red Raspberries ................................... 14 Everbearing Raspberries ............................ 15 Blackberries ...................................... 15 Currants and Gooseberries ........................... 15 Glossary ......................................... 16 General Rules for Pruning ........................... 17 ACKNOWLEDGMENT The authors
    [Show full text]
  • Tree Identification ISA Certified Arborist
    Panelists: (comprised of urban foresters and certified arborists) • John Warner, Texas A&M Forest Service, Facilitator • Jordy Herrin, Texas A&M Forest Service, Chat box monitor • Mark Kroeze, Texas A&M Forest Service • Jack Hill, Burditt Consultants, LLC • Michael Gabrielse, Burditt Consultants, LLC What we will cover today in All About Trees Tree Pruning: Why prune, pruning types, pruning guidelines, wound wood, codominant stems, bad pruning habits, physiological characteristics of trees Tree Planting: Proper planting, when to plant, planting stock Tree Facts & Quiz Tree Root Architecture Small absorbing roots Lateral roots Sinker roots Taproot = Topping a tree is considered a healthy way of pruning. True or False? False! Topping, de- horning, hat-racking or what ever you want to call it is NOT recognized by any of the professional arboriculture organizations, urban forestry professionals or certified arborists as an approved method of pruning. Pruning Trees Proper pruning helps keep plants’ attractive and vigorous and will add years to the plant’s health. Many people are apprehensive about pruning, but knowing how, when and why to prune will end these fears. Basic Pruning Questions May include but are not limited to: – Three D’s – Dead, Dying or Diseased – Improve Tree Structure & Form – Crowded – Reducing risk – Potential hazards – Improving aesthetics – Satisfying a specific need Basic Pruning Guidelines •Prune first for safety, next for health, and finally for aesthetics. •Never prune trees that are touching or near utility lines; instead consult your local utility company. •Always have a reason for pruning •TREES DO NOT HEAL THEY SEAL Basic Pruning Guidelines • Remove broken or hanging limbs immediately before they fall.
    [Show full text]
  • Introduction to Horticulture 3
    1 Introduction to Horticu ltu re INTRODUCTION Horticulture is a science, as well as, an art of production, utilisation and improvement of horticultural crops, such as fruits and vegetables, spices and condiments, ornamental, plantation, medicinal and aromatic plants. Horticultural crops require intense care in planting, carrying out intercultural operations, manipulation of growth, harvesting, packaging, marketing, storage and processing. India is the second largest producer of fruits and vegetables in the world after China. In India, about 55–60 per cent of the total population depends on agriculture and allied activities. Horticultural crops constitute a significant portion of the total agricultural produce in India. They cover a wide cultivation area and contribute about 28 per cent of the Gross Domestic Product (GDP). These crops account for 37 per cent of the total exports of agricultural commodities from India. SESSION 1: HORTICULTURE AND ITS IMPORTANCE The term horticulture is derived from two Latin words hortus, meaning ‘garden’, and cultura meaning ‘cultivation’. It refers to crops cultivated in an enclosure, i.e., garden cultivation. Chapter -1.indd 1 11-07-2018 11:33:32 NOTES Features and importance Horticulture crops perform a vital role in the Indian economy by generating employment, providing raw material to various food processing industries, and higher farm profitability due to higher production and export earnings from foreign exchange. (a) Horticulture crops are a source of variability in farm produce and diets. (b) They are a source of nutrients, vitamins, minerals, flavour, aroma, dietary fibres, etc. (c) They contain health benefiting compounds and medicines. (d) These crops have aesthetic value and protect the environment.
    [Show full text]
  • From Dendrochronology to Allometry
    Concept Paper From Dendrochronology to Allometry Franco Biondi DendroLab, Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV 89557, USA; [email protected]; Tel.: +1-775-784-6921 Received: 17 December 2019; Accepted: 24 January 2020; Published: 27 January 2020 Abstract: The contribution of tree-ring analysis to other fields of scientific inquiry with overlapping interests, such as forestry and plant population biology, is often hampered by the different parameters and methods that are used for measuring growth. Here I present relatively simple graphical, numerical, and mathematical considerations aimed at bridging these fields, highlighting the value of crossdating. Lack of temporal control prevents accurate identification of factors that drive wood formation, thus crossdating becomes crucial for any type of tree growth study at inter-annual and longer time scales. In particular, exactly dated tree rings, and their measurements, are crucial contributors to the testing and betterment of allometric relationships. Keywords: tree rings; stem growth; crossdating; radial increment 1. Introduction Dendrochronology can be defined as the study and reconstruction of past changes that impacted tree growth. The name of the science derives from the combination of three Greek words: δ"´νδρoν (tree), χρóνo& (time), and λóγo& (study). As past changes can be caused by processes that are internal as well as external to a tree, both environmental factors and tree physiology are subject to dendrochronological inquiry. Knowledge of the principles and methods of tree-ring analysis therefore allows the investigation of topics ranging from climate history to forest dynamics, from the dating of ancient ruins to the timing of wood formation.
    [Show full text]