22.14.5 THE CARBON-TO-NITROGEN RATIO FACTOR Grass clippings have a high nitrogen composition and hence a lower C:N ratio than dried leaves. If the nitrogen in the compost heap is too low, it will heat up. However, if the nitrogen proportion is too high, the heap may become too hot, killing the decomposers, or become anaerobic, resulting in a foul-smelling compost heap. Usually, a good starting C:N ratio is 30:1. This ratio reduces to 10:1 at the end of a good composting process. The carbon-to-nitrogen (C:N) factor is a measure of the material’s relative proportion of carbon to nitrogen. The higher the value, the lower the nitrogen content and the longer it takes to decompose. A C:N ratio of 30 is best for composting. Straw has a C:N ratio of 80, while sawdust has a ratio of 400. Materials of leguminous origin have a low C:N ratio (e.g., 15). While a high C:N ratio material decomposes slowly, using materials of low C:N ratio produces excess nitrogen that is expelled from the heap in the form of ammonia gas. 22.14.6 TIME FACTOR Plant breeders in a way cause artificial evolution to occur in their breeding programs. The difference between their activities and natural evolution is the fact that natural evolution requires an estimated millions of years while a plant breeding program may be completed within ten years. Natural evolution depends on natural selection to guide it, while plant breeding relies on artificial selection imposed by the breeder. Similarly, a biodegradable material eventually decomposes, if left in the soil long enough. However, a gardener may not be able to wait for nature to take its course. To accelerate the process of decomposition, a compost pile is inoculated with materials called activators. They contain good populations of decomposers and a nitrogen-protein source to sustain the decomposers in the initial stages of composting. 22.14.7 COMPOST ACTIVATORS There are natural and artificial compost activators. Natural Activators Natural activators include the following: 1. Loamy soil. The decaying organic component of a loamy soil contains soil microbes. 2. Compost. For the person who composts frequently, finished compost from a previous pile may be used to inoculate a fresh compost heap. 3. Protein meal. Protein meal may be derived from high-protein plant material, such as alfalfa and cotton seed. Animal sources include fish meal, bone meal, and blood meal. 4. Manure. Manure from a variety of farm animals including poultry, cattle, and sheep is a good activator. However, it should not be used fresh, since it is safest when well decomposed. Manure may be decomposed by allowing the fresh substance to sit exposed to the weather for several weeks. Unfortunately, manures contain weed seeds, which could be a problem if the composting process does not reach the peak temperature required to kill weed seeds. Artificial Activators Artificial activators include the following: 1. Fertilizers. Fertilizers are less efficient than natural activators because they lack protein. Compound fertilizers consisting of nitrogen, phosphorus, and potassium (10:10:10) may be used. 2. Inoculant. Commercially prepared dormant bacteria and fungi that are packaged as tablets or granules may be used. 22.14 Composting 663
22.15 COMPOSTING SYSTEMS Methods of composting are varied and adaptable to one’s needs and situation, once certain general guidelines are observed. There are designs for small-scale and indoor use, and others for large-scale and outdoor production of compost. They also vary in terms of ease of aeration, cost of setup and maintenance, time to completion, quality of product, and odor. The two types of compost systems are categorized on the basis of the receptacle. No-Container Method (Sheet Composting) The ultimate goal of composting is to decompose plant material for incorporation into the soil to improve its nutrient level and physical characteristics. The most direct way of accomplishing this is to use in situ composting, in which the plant material is composted in the soil where it will be used. The material used may include leaves, plant residue after harvesting, grass clippings, and manure hauled onto the field. These materials are incorporated by an appropriate implement such as a spade or a mechanical tiller. Another version of this method, called green manuring, involves the growing of leguminous species, such as clover, alfalfa, peas, and soybean, and plowing them under while still fresh. Sheet composting allows organic materials to be applied to large fields. A negative side of this method is that it takes several months for the incorporated material to decompose. Also, when materials of high C:N ratio are used, the soil experiences a short period of nitrogen deficiency (nitrogen starvation) because the existing nitrogen is used in decomposition. Crops therefore should not be planted until several months after composting, when the nitrogen deficiency has been corrected. Another negative factor is that heat does not build up to a level at which weed seeds are killed. Container Methods Gardeners also compost in specially constructed containers or pits. These methods of composting follow certain recipes, depending on the design. The compost is prepared in one place and transported to another for use. 664 Chapter 22 Organic Farming 22.16 GENERAL PRINCIPLES OF CONSTRUCTING AND MONITORING A COMPOST HEAP The success of composting depends on the observance of certain principles including layering, moisture supply, size of pile, and aeration. When monitoring the compost heap, be sure to take multiple measurements of temperature, pH, and moisture content, since these factors vary within the heap. Right Mix and Layering Layering or arrangement of the organic material in the compost pile is important. However, the key to a successful composting is to start with the right mix of ingredients. In this regard, the key factors of concern are the moisture content and the C:N ratio of the ingredients. Since one is encouraged to use a wide variety of materials in a compost pile, the way they are arranged in the pile is important. Materials are not haphazardly mixed up in the pile but rather are placed strategically in layers. For example, layers of dry materials such as straw should be alternated with fresh materials such as clippings and vegetative matter. Materials high in nitrogen (low C:N) should be alternated with high-carbon (high C:N ratio) material. After a number of layers, the activator should be spread evenly before another set of material is added. This pattern is repeated until the container is filled. Particle size also affects the rate of decomposition of the organic materials. Particles in the heap should preferably not exceed 2 inches in size.
HORTICULTURE Principles and Practic
HORTICULTURE Principles and Practic
With love to Theresa, quarterback;
Brief Contents Preface xxi PART 1 T
Contents Preface xxi PART 1 THE UND
5.3 PLANT GROWTH PROCESSES 160 5.4
8.20 COMMON GREENHOUSE DISEASES 276
12.3 INTERNAL ENVIRONMENTAL CONTROL
PART 6 Summary 541 References and S
22.18 INDOOR COMPOSTING SYSTEMS 668
Preface Horticulture is the area of
ACKNOWLEDGMENTS I am very grateful
PART 1 THE UNDERLYING SCIENCE CHAPT
1 What Is Horticulture? PURPOSE AND
(a) (c) (b) (d) FIGURE 1-1 The many
FIGURE 1 Bridge. The plaza view of
CYCADS Many people mistake these pr
FIGURE 2 The world's largest unbran
FIGURE 2 Sold flowers are loaded on
FIGURE 1-4 Formal landscaping featu
1.4 ROLEOFTHENURSERY AND SEED INDUS
1.5 HORTICULTURE AND SOCIETY Hortic
TABLE 1-3 U.S. Horticultural Export
Turfgrass Operation 1. Landscape te
What Is Horticulture? This site pro
Examples of botanical gardens http:
2 Classifying and Naming Horticultu
Eight major taxa are commonly used
TABLE 2-3 The Divisions of the King
HISTORY OF PLANT TAXONOMY PAUL R. F
AGE OF HERBALISTS Two major events
possible system of nomenclature. Ho
TABLE 1 Type Categories for Plant N
2.3 OTHER CLASSIFICATION SYSTEMS (O
2. Shrubs. A shrub has no main trun
Simple Fruits Fleshy Fruits Drupe B
FIGURE 2-14 A pome, represented by
2.3.5 CLASSIFICATION OF VEGETABLES
(a) (b) FIGURE 2-22 (Source: George
FIGURE 2-25 A narrowleaf plant. (So
FIGURE 2-29 Parts of a typical gras
such as rosemary, sage, thyme, marj
c. Leaves d. Bulbs 2. Cut across (t
Whole plant Organs FIGURE 3-1 Level
ibonucleic acid (RNA), proteins, an
called cristae; this extreme foldin
By virtue of its position, the prim
Phloem Tissue Structurally, phloem
(a) Stalk (b) Culm FIGURE 3-5 Cross
Scale Compressed stem (a) Whole bul
Upper epidermis Palisade layer FIGU
usually occur in xerophytes. In cer
FIGURE 3-22 Selected common leaf ma
FIGURE 3-25 Selected common leaf ti
absorption of water and minerals fr
Outer bark Inner bark FIGURE 3-37 T
Anther Filament Stamen FIGURE 3-41
Exocarp Parts of a typi- FIGURE 3-4
PRACTICAL EXPERIENCE LABORATORY 1.
4.1 CLIMATE, WEATHER, AND HORTICULT
concentration in the atmosphere.A c
TABLE 4-1 Climatic Adaptation of Se
and upward. Another important gener
Rate of photosynthesis mg/sq. dm/hr
and plants that flower under only c
times of the year. Growers start th
content. This section is sometimes
TABLE 4-7 Soil Mineral Nutrients Es
Micronutrients (Trace Elements) Mic
Neutral FIGURE 4-11 A representatio
4.4 FERTILIZERS Fertilizer sources
One of the most commonly used contr
Chlorosis (the yellowing of green l
Fertilizers may be applied before p
It is neither practical nor safe to
Solution: How much of ammonium nitr
1°C (34°F), the optimum temperatu
Cellulose sponge Perched water tabl
Overhead Sprinkler Irrigation Water
FIGURE 4-19 Furrow irrigation of le
can self-install an underground irr
1. Surface drainage. Surface draina
Secondary Tillage Primary tillage i
(a) (b) (c) (d) FIGURE 4-20 (Source
texture. The most commonly used gra
TABLE 4-11 Selected Standard Mixes
Steam Pasteurization Steam pasteuri
Maracher, H. 1986. Mineral nutritio
5 Plant Physiology PURPOSE AND EXPE
Growth in an organism follows a cer
5.1.2 THE ROLE OF SIGNALS IN GROWTH
waxes are embedded. Waxes consist o
5.3.1 PHOTOSYNTHESIS Photosynthesis
CO 2 FIGURE 5-6 The C 4 pathway of
Growth and Development The general
TABLE 5-2 Energy Produced from Aero
Certain plants are adapted to dry e
conditions exist to sustain growth
Shoot Elongation In certain plants,
for success, since high temperature
FIGURE 5-13 Ripening of plantain sh
Terminal bud removed Unbranched pla
conditions—pertaining to light, m
them to maturity. The major process
6 Breeding Horticultural Plants PUR
Similarly, there can be no plant br
APPLICATION, CHALLENGES, AND PROSPE
hit with target DNA. Therefore, it
Generally, within ten days of exper
Aziz A.N., Sauve R.J., Zhou S., 200
(b) F 1 Rr Rr round round F 2 RR R
e.g., Aa × Aa), the lethal allele
eeder’s equation. Simply stated,
Before the seed or product becomes
6.18.2 THE GENERAL STEPS OF RDNA TE
2. Political disagreement. There ar
REFERENCES AND SUGGESTED READING Ac
PART 2 PROTECTING HORTICULTURAL PLA
7 Biological Enemies of Horticultur
8. Weeds may clog drains, waterways
is also a root parasite that obtain
LEGISLATIVE Both state and federal
Example Integrated cultural, physic
7.4.2 IMPORTANT INSECT ORDERS Insec
Egg FIGURE 7-3 Life cycle of an ins
sucking insects (also found with so
FIGURE 7-12 Corn earworm damage. (S
TABLE 7-1 Selected Fungal Diseases
7.6.1 SMALL ANIMALS Rabbits, mice,
FIGURE 7-16 The disease triangle. P
fungitoxic exudates in its leaves,
SUMMARY Insects are a major class o
For the home growers or those who c
for consumers and the environment).
TABLE 8-1 Strategy 4: Strategies an
gibberellic acid spray overcomes st
In a competitive industry, a variet
Chemicals gain access to humans thr
2. Pesticide management. Controllin
Every organism has its natural enem
TABLE 8-3 Selected Examples of Biol
1 2 YEAR 3 4 FIGURE 8-5 cycle. A cr
6. Heat treatment. In the greenhous
Organic Compounds (Organics) Organi
under enclosed conditions (e.g., wa
FIGURE 8-9 A tractor-mounted spraye
8.11.9 LANDSCAPE PESTS AND THEIR CO
application, a particular herbicide
Further, they do not provide unifor
SUMMARY Herbicides are chemicals us
Sulfur may be applied for both prev
8.23 PREVENTING GREENHOUSE DISEASES
PART 3 PROPAGATING HORTICULTURAL PL
9 Sexual Propagation PURPOSE AND EX
Anther Microspore Megaspore mother
Lettuce seeds Red light Darkness Fa
FEDERAL AND STATE SEED LAWS Federal
Germination Test In laboratory prac
FIGURE 15 The essential structures
processing into flour or meal). How
physiologically immature seeds must
seeds may be treated in this way be
The two basic modes of seedling eme
locations in the field. Home garden
FIGURE 9-9 A plastic flat. (Source:
(a) (b) FIGURE 9-12 (a) Sowing seed
y the gardener or grower. Whatever
REFERENCES AND SUGGESTED READING Co
species enables vegetative propagat
for rapid rooting. There are two ba
Cutting involving one node (e.g., s
This practice is especially importa
10.6.4 STICKING THE CUTTING Cutting
(a) Indexing by budding Diseased pl
10.11 M ETHODS OF GRAFTING Grafting
Scion Wax FIGURE 10-17 Steps in bar
MODULE 3 BUDDING 10.12 TYPES OF BUD
MODULE 4 LAYERING 10.13 TYPES OF LA
Buried part of shoot is nicked FIGU
variety of ways. In air layering, a
FIGURE 10-34 by using cormels. Prop
Psuedobulbs In the Dendrobium orchi
The technique is used widely in cro
PART 4 GROWING PLANTS INDOORS CHAPT
11 Growing Houseplants PURPOSE AND
TABLE 11-1 Common houseplants Commo
Saddle leaf Philodendron selloum To
Window Displays Plants in windows e
CONTAINER GARDENS DR. TERRI W. STAR
annuals and hardy perennial species
of the large container filled with
perfection about four to six weeks
FIGURE 11-6 Flowers displayed on th
TABLE 11-5 Plant Selected Plants fo
The lighting condition near these w
Fluorescent Lights Fluorescent ligh
may be used for one pot or a group
garden rooms, atriums, or a large c
The photoperiod affects when the ho
patted firm to keep the plant erect
Other Materials Apart from clay and
(a) ( FIGURE 11-25 Support for plan
TABLE 11-7 Common Problems of House
• Keep soil moist all the time
• Prefers high temperatures • P
amount and quality of light. If sup
12 Controlled-Environment Horticult
6. Curvilinear 7. Curved eave 8. Do
Detached greenhouses have several a
12.2.3 FRAME DESIGN There are two b
horticultural business a less-expen
Texas, Hawaii, and California. The
source of heat for times when the t
FIGURE 12-17 Greenhouse production
FIGURE 12-21 Moving tables allowing
Research program on greenhouse engi
greenhouses equipped with a variety
FIGURE 1 Annual energy required per
This system was demonstrated in a 5
FIGURE 6 Amounts of waste energy ut
Ekholt, B.A., D.R. Mears, M.S. Gini
or object to be warmed. Failure to
objects in its path (e.g., the floo
FIGURE 12-27 Motorized ventilation
FIGURE 12-30 Movable internal shade
FIGURE 12-33 A high pressure sodium
Source of Water The quality of loca
FIGURE 12-37 Overhead sprinkler irr
Intermittent Feed Greenhouse plants
However, in winter, greenhouse vent
OUTCOMES ASSESSMENT 1. Explain the
. Foliage or green plants. Foliage
2. Labor. The size of the labor for
FIGURE 13-1 Greenhouse production o
FIGURE 13-2 Lettuce plug is inserte
13.8.4 AGGREGATE HYDROPONIC SYSTEMS
(a) (b) (c) FIGURE 13-6 Plug produc
14 Growing Succulents PURPOSE AND E
FIGURE 14-3 Leaf succulent represen
frost-hardy. Their rosettes are usu
TABLE 14-1 Plant Selected Popular S
(a) (b) FIGURE 14-12 Typical bromel
14.7.1 WHAT ARE CACTI? 14.7 CACTI C
FIGURE 14-16 Opuntia. (Source: Crai
FIGURE 14-23 Mammillaria. (Source:
FIGURE 14-28 Both desert and jungle
Growing mix Gravel Cacti (a) (b) FI
PART5 GROWING PLANTS OUTDOORS: ORNA
15 Principles of Landscaping PURPOS
8. Create recreational grounds. Suc
knowledge, with concern for resourc
(a) (b) (c) FIGURE 15-2 The occurre
GUIDELINES FOR LANDSCAPE DESIGN DAV
the landscape. Some very successful
Rhythm and Line Panoramic view of a
FIGURE 15-10 A formal garden. The e
How frequently do they entertain? A
the patio should be located on the
15.7.1 SELECTING PLANTS A homeowner
Plant Arrangement in the Landscape
Shadow FIGURE 15-15 Planting a tree
SUMMARY Landscaping enhances the su
3. Supply materials on a timely bas
such as preparation rooms (for mixi
of environmental fluctuations. Furt
FIGURE 16-4 A bare-root tree seedli
17 Installation of the Landscape PU
for walks, driveways, and patios (F
Planting may be limited to accentin
17.3.3 PREPARING THE BED The soil s
FIGURE 17-4 Bedding plants raised i
SUMMARY Bedding plants are largely
TABLE 17-6 Selected Ground Covers T
TABLE 17-7 Selected Ornamental Gras
they determine the success and surv
12. Wildlife attraction. Trees in t
pennsylvanica), hackberry (Celtis s
y winds. A stake, which is often a
TABLE 17-8 Selected Narrowleaf Ever
TABLE 17-11 Selected Deciduous Shru
Blooming bushes 1. Blue mist shrub
Planting Bulblets and Bulbils Speci
may be divided such that each secti
FIGURE 18-1 (Source: George Acquaah
Cool-Season (Temperate) Grasses In
Growth Habit Turfgrasses are the mo
Heavy Use Lawns on playgrounds and
The seed should be free from weeds
Source of Sod As with seed, sod sup
A plug of sod FIGURE 18-7 Plugging
way, plants are able to adapt to th
form of a can placed on the lawn wi
TABLE 18-3 Some Common Lawn and Tur
even surface soil surface for layin
MacCaskey, M. 1987. All about lawns
Pruning is sometimes done in conjun
4. Pruning may be done to reduce th
19.4.2 SAWS A saw may be designed t
defeat the purpose of pruning. The
Bud withers as cut end dries back d
19.6 STRATEGIES FOR PRUNING ABOVEGR
Rejuvenation Pruning Cut canes to a
3. In the third and subsequent year
(a) Cut Prune (b) FIGURE 19-16 Step
Eucalyptus and Paulownia are amenab
TRAINING & PRUNING DECIDUOUS FRUIT
Summer pruning eliminates an energy
a) b) FIGURE 2 Newly planted apple
FIGURE 6 Wooden limb spreaders can
FIGURE 9. An apple tree trained to
years to promote continued lateral
Horizontal Espalier The horizontal
19.16.1 CANE FRUITS Cane fruits are
FIGURE 19-26 Shearing of Christmas
pyramid-like form that is wider at
After selecting the appropriate spe
PART 6 GROWING PLANTS OUTDOORS: VEG
20 Growing Vegetables Outdoors PURP
TABLE 26-3 Plant A Selection of Pop
26.3.1 COLLECTING BONSAI PLANTS FRO
Strip bark Bare branch FIGURE 26-9
26.5.2 SANITATION It is critical to
27 Postharvest Handling and Marketi
whereas oranges are picked (they ha
(b) (a) (c) (d) (e1) (e2) (f) FIGUR
To reduce packaging injury, contain
is replaced by the by-product of re
Stored produce may lose some color,
with pricing. When selling by volum
(a) (b) FIGURE 27-5 Horticultural p
APPENDIX A Temperature: Converting
APPENDIX B Metric Conversion Chart
APPENDIX D Common and Scientific Na
Pecan (Carya illinoensis) Peony (Pa
GLOSSARY A Abaxial Turned away from
Cellulose A complex carbohydrate th
Floriculture The science and practi
M Macronutrient An essential elemen
Root cap A mass of hard cells cover
INDEX A-frame, 395 A-horizon, 108 A
defined, 390 fertilization, 432-434
Radiant heaters, 378 Radicle, 90 Re
color plate 1 (a) (b) (c) (d) (e) M
color plate 3 (b) (a) (c) (d) (e) (
color plate 5 (a) (b) (d) (c) (e) (
color plate 7 (b) (c) (d) (a) (e) (
color plate 9 (a) (b) (c) (d) (e) (
color plate 11 (a) (c) (b) (d) Grow
color plate 13 (a) (b) (c) (d) (e)
color plate 15 (a) (b) (c) (d) (e)
color plate 17 (a) (b) (c) (d) (e)
color plate 19 (a) (b) (c) (d) (e)
color plate 21 (a) (b) (c) (e) (d)
color plate 23 (c) (b) (a) (d) (e)
color plate 25 (c) (a) (b) (d) (e)
color plate 27 (a1) (a2) (b2) (b1)
color plate 29 (a) (b) (c) (d) (e)
color plate 31 (a) (b) (c) Floral d
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