processing into flour or meal). However, cracked seeds can significantly reduce the market value of the produce in other markets. Mechanical damage may be determined by a simple laboratory procedure as follows: 1. Obtain twenty to fifty seeds (randomly selected) from the lot. 2. Place a sample in a petri dish containing a 1 percent sodium hypochlorite solution. (If household bleach is used, it should be noted that it contains 5.25 percent sodium hypochlorite.) 3. Soak seeds for fifteen minutes. 4. Count the number of swollen seeds. 5. Count the number of swollen seeds after soaking for thirty minutes. 6. Calculate percent cracked seed as follows: number of swollen seeds total number of seeds 100 9.5 SEED VIABILITY AND LONGEVITY Seeds may look healthy but fail to germinate when planted. Two other seed qualities that are essential but not displayed on the seed envelope are viability and longevity. Viability is a measure of the proportion of seeds in a lot that are capable of germinating. Longevity is a measure of how long seeds remain viable. Viability is measured using germination and tetrazolium tests. Species in the pumpkin family (Cucurbitaceae) (e.g., cucumber, squash, and cantaloupe) remain viable for a long time (sometimes for several years), whereas species in the lily family (Liliaceae), including onion and leek, lose viability only about two to three months after harvesting. Seeds of pine, hemlock, and spruce remain viable with proper storage for several years. On the contrary, seeds of maple, elm, and willow have a very short period of viability, lasting only a few weeks. Apart from longevity inherent in the plant species, viability of seed during storage depends on the storage environment as pertains to seed moisture content temperature, and relative humidity. Seed longevity depends on the species and the conditions at harvest and during storage. Seeds should be stored only when they have attained the appropriate moisture content (usually less than 15 percent). Seed dried to about 7 percent moisture and under low relative humidity can be stored for a long time in a refrigerator (0 to 4°C or 32 to 39°F). Very low relative humidity of about 5 percent allows seeds to be stored for a long time while retaining the highest level of viability. However, a relative humidity of 50 to 65 percent maintains the viability of most seeds for about one year. To increase longevity, seeds may be stored cryogenically in liquid nitrogen at 192°C (313.6°F) for years. For ordinary storage, ziplock plastic bags, or bottles are adequate containers. Seed Viability The proportion of seed in a lot that is capable of germinating. Seed Longevity A measure of how long seed remains viable. 9.6 TAGGING COMMERCIAL SEED Before certified seed can be released for sale to customers, it must be identified with an appropriate tag. Tags are color-coded. A white tag identifies breeder or foundation seed, a purple tag for registered seed, and blue tag for certified seed. Sometimes, a breeder may have seed that meets certification standards and yet opt not to have it certified. Such seed is identified with a green tag. Apart from these color codes, a seed tag displays some basic information about seed quality and source. The interpretation of the information on the tag is presented in Table 9–1. 9.6 Tagging Commercial Seed 295
9.7 PURCHASING SEED Select seed cultivars that are adapted to your locality. Extension agents can assist you in making the right choice. Select fresh seeds if possible, and have them ready to plant on time. Seeds should be purchased from a reputable grower or store. The date of harvest is usually printed on the seed packet. Mail-order purchases are available through a variety of outlets. Seed companies produce seed catalogs on an annual basis. Some small seed companies may provide seed at a lower cost to growers. However, more established companies provide a variety of information on the seed packet to guide the grower with limited knowledge about growing plants. 9.8 SEED COMPANIES The seed industry was introduced in Chapter 1. The seed market is very lucrative worldwide. There are numerous small seed producers, some specializing in vegetables, specialty crops, and ornamentals. Being a lucrative area, mergers and acquisitions have characterized the seed industry in the past two decades, some of the recent shuffling including the acquisition of Novartis by Monsanto in 2005, and prior to that Syngenta (formerly Novartis/Astra Zeneca), Pioneer incorporating Dupont, and the merger of Monsanto and Pharmacia. These behind-the-scene corporate maneuverings notwithstanding, growers of horticultural crops deal with the smaller seed companies that specialize in their crop or plant species of interest. 9.9 SEED DORMANCY Seed Dormancy The failure of viable seed to germinate under adequate environmental conditions. All seeds do not germinate, even when optimal conditions are provided. A physiological or structural adaptive mechanism called dormancy imposes further restrictions on the requirements for germination. Seeds germinate only after the dormancy is overcome or broken. Dormancy is desired in the wild, where plants depend entirely on nature for survival. It prevents germination in the face of adverse weather, which will kill the vulnerable seedlings after emergence. Structural dormancy is imposed via the seed coat (seed coat dormancy) (e.g., Camellia and redbud). Hard seed coats are impermeable to the much needed moisture that is critical for germination. The seed coat may be softened before planting by one of several methods, such as scarification, a method of mechanically scratching the seed coat (by, for example, tumbling seeds in a drum containing coarse material). Seeds may also be scarified by soaking them in concentrated sulfuric acid or household bleach for a period. Physiological dormancy (embryo dormancy) occurs when the embryo requires a special treatment to induce it to start active growth. A cold temperature application (called stratification) of about 1 to 7°C (34 to 45°F) is commonly required to break the dormancy. Woody species like holly (Ilex spp.) and magnolia (Magnolia grandiflora) require this treatment. Seed to be stratified is soaked in water for about twelve to twentyfour hours prior to placement in a sterile medium container such as a polyethylene bag to hold in moisture. The medium should permit good aeration to occur. Effective media include coarse vermiculite, sphagnum moss, coarse sand, or a mixture of equal volumes of peat and perlite. Seed may be wrapped in cheese cloth prior to placement in the medium to eliminate the need for cleaning the seed after the treatment. Stratification in the fridge takes about three to four months to complete. A number of chemicals in plants inhibit germination of seeds while they are still embedded in the pulp of the fruit (e.g., in tomato and strawberry). In some species, such as Pinus and Ranunculus, the fruits are shed before the embryo fully matures. Such 296 Chapter 9 Sexual Propagation
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).
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
The National Agricultural Statistic
(This item omitted from WebBook edi
growers should take to determine an
pests and reduce/ eliminate hail da
square yard (10 to 68 grams per squ
High tunnels help increase the prof
(This item omitted from WebBook edi
20.4 VEGETABLE MARKET TYPES Fresh V
Establishing the Crop Planting into
home water supply from the tap. Thi
Cole crop Cabbage Root Potato Bean
6. Adequate nutrition. While overfe
variable, ranging from creamy yello
There are two general production pr
This toxin is heat resistant and no
large, or jumbo. The bulb may be sw
REFERENCES Growing selected vegetab
TABLE 21-1 Popular Herbs and Their
(a) (b) (c) (d) (e) (f) FIGURE 21-1
22 Organic Farming PURPOSE AND EXPE
22.3 PRINCIPLES OF ORGANIC FARMING
and the specific materials to be us
22.8 MANAGING SOIL PHYSICAL QUALITY
preemergent or early postemergent o
Composting is a deliberate activity
22.14.5 THE CARBON-TO-NITROGEN RATI
Moisture Supply Water is required b
Compost materials FIGURE 22-4 a wir
As microbial decomposition proceeds
Establishment and Management of an
night, freezing can occur in spring
accomplished by stratification. It
transmitted by the dagger nematode
PART 7 SPECIAL TECHNIQUES AND HANDL
24 Cut Flowers and Floral Design PU
to more than four-fold in standard
Temperature and Humidity Wilting re
FLORAL DESIGN: AN OVERVIEW BY WM. J
Principle Definition Types (or Uses
pH value-a measure of the acidity o
FIGURE 6 Parallel Design-Parallel d
24.3.2 TOOLS AND MATERIALS The tool
3. Establish the focal point. 4. Ad
Natural Drying To dry naturally, fl
24.4.3 DRIED FLOWER ARRANGEMENTS Dr
25 Terrarium Culture PURPOSE AND EX
FIGURE 25-3 Terrarium containers ar
FIGURE 25-5 Assortment of tools use
25.6.7 ENHANCING THE DISPLAY Certai
(a) (b) FIGURE 26-1 Bonsai can be c
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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Magazine: Horticulture Principles and Practices