Organic Compounds (Organics) Organic insecticides may be natural or synthetic. Natural (Botanicals) Botanicals are products from plants that have insecticidal effects. Many plant species produce organic compounds that are toxic to insect pests that feed on them. Plant organic substances are usually safe and nontoxic to humans. An example of a botanical is pyrethrum, which is obtained from chrysanthemum. Another organic substance is nicotine, which is obtained from tobacco plants and is an addictive substance found in cigarettes. Other botanicals are rotenone, ryania, and sabadilla. Many organic compounds act as stomach or contact poisons. Synthetic Organic Compounds Synthetic organic chemicals are artificially compounded and are effective against a wide variety of insects and pests. On the basis of the active ingredients in chemicals, several classes of synthetic organic insecticides are identified: 1. Organochlorines (chlorinated hydrocarbons). Organochlorines are most readily associated with dicarbo-, dihydrotetrachloride (DDT), which is one of the earliest and most successful to be developed. It has wide application, being effective against horticultural field pests, mosquitoes, fleas, and flies. It has a long residual effect, working long after initial application. Organochlorines are not readily biodegradable, which contributes to their rapid buildup in the environment in the soil and water, as well as in the tissues of plants and animals and their products. They are thus not only toxic to humans through their action on direct contact but also through the ingestion of food that has been contaminated, such as dairy and meat products (i.e., through a cow eating contaminated feed) and fish from contaminated waters. Consequently, DDT (as well as its close relatives) has been banned in many parts of the world. Other organochlorines are chlordane, lindane, methoxychlor, heptachlor, and aldin. 2. Organophosphates. Unlike chlorinated hydrocarbons, organophosphates (or organic phosphates) have shorter residual action (breakdown within thirty days) and are more readily biodegradable. As such, they do not build up in the environment. However, certain types (e.g., parathion) are extremely toxic to humans. Organophosphates are generally effective insecticides. Malathion is less toxic and widely used as a horticultural spray. Other organophosphates include diazinon, phorate, dameton, and chlorpyrifos. 3. Carbamates. Carbamates are relatively safer to use than those previously described. They have somewhat low mammalian toxicity and short residual action (breakdown within seven days). They are effective against sucking and chewing insects. One of the earliest and most successful was carbaryl (trade named Sevin). Others are carbofuran, aldicarb, and propoxur. 4. Pyrethroids. Pyrethroids are synthetic equivalents of natural pyrethrins found in species such as chrysanthemum. They are less toxic to humans and effective against a broad spectrum of insects. Fumigants Fumigants act in the gaseous state and are best used in closed environments (e.g., as storage pesticides) or injected into the soil. One of the most common types is methyl bromide, an odorless and colorless gas that is highly toxic to humans but is used widely to fumigate stored vegetables, seeds, fruits, and grains. It is also used to chemically sterilize soil mixes for use in greenhouses. Malathion is one of the most widely used fumigants of stored grain. Spray Oils Spray oils are obtained by specially distilling and refining crude oils. They are used to combat scale insects and mites in orchard plants and ornamentals. A common form is called dormant spray. 8.11 Insecticides and Their Use 263
Biologicals (Microbial Insecticides) Biologicals are commercially produced pathogens (e.g., bacteria, fungi, and viruses) that are applied to the foliage of plants to prey on specific insect pests. For example, commercial preparations of the bacterium Bacillus thuringiensis are applied to foliage to control several species of Lepidoptera (caterpillars). Formulation The form in which a pesticide is offered for sale. Drift The movement by air of pesticide particles outside the intended target area during or shortly after application. 8.11.3 FORMULATIONS OF INSECTICIDES The chemical that actually controls the target pest (active ingredient) is not marketed or utilized directly but mixed with an inert ingredient to create what is called a formulation. Although some formulations are ready to use, others require diluting with a solvent or water before use. The two general types of formulations are dry and liquid. Dry Formulations Dusts Dusts are chemicals formulated as powders and applied as such without mixing or diluting. They usually contain low concentrations of the active ingredient or ingredients (about 1 to 10 percent) mixed with fine-powdered inert material (e.g., chalk, clay, or talc). Dusts are applied by using simple equipment called dusters. They are easy to apply but leave unsightly residue on foliage. Further, when applied in even the slightest wind condition, drift (blowing away in the wind) may be a problem. Drifting of a pesticide onto plants not intended to be sprayed may result in collateral damage. Wettable Powders Wettable powders are concentrated chemicals formulated as dusts or powders that require dilution before use. Wettable powders are usually formulated to a high concentration of active ingredient (about 50 percent or greater). The addition of water decreases drift, but since the powders, even in solution, tend to settle, care should be taken to stir the mixture frequently so that the chemical is applied uniformly and at the desired rate. To increase the effectiveness of pesticides that require mixing with water before use, they are mixed with surfactants (agents that help pesticides to stick or spread better by lowering surface tension). This mixing is necessary because the plant surface naturally repels water to a varying extent. Wettable powders require constant agitation during use. Granules Sometimes insecticides are formulated as coarse particles called granules. Granules are applied to the soil in the same way as granular fertilizer formulations are applied. They may require dissolution in water before roots can absorb the chemicals. Some may have to be incorporated into the soil. Systemic herbicides may be formulated this way. Other granules are designed to act like fumigants and thus need no water to initiate their effects. Granules are ready to use and pose little danger to the user. There is no danger of drift, and application requires only simple equipment such as a spreader. Pellets Pellets differ from granules in that the former consists of particles that are uniform in size and of specific weight. Unlike granules, pellets can be applied by precision applicators. Baits When an active ingredient is mixed with food or some other substance that attracts pests, the formulation is called a bait. Pests are attracted to baits and die when they ingest the poisons. Baits are usually low in active ingredient (less than 5 percent). They are commonly used to control indoor pests including mice and cockroaches. Liquid Formulations Aerosols Aerosols contain one or more active ingredients in a solvent. Household chemicals are frequently formulated as aerosols. These insecticides are contained in pressurized cans and are ready for use. They are very convenient to use but still require adherence to the safety measures that apply to all insecticides. The insecticides are propelled by special gases (propellants) including fluorocarbons (e.g., freon), isobutane, and isopropane. Aerosols may be formulated for use as smoke or fog in special generators 264 Chapter 8 Principles and Methods of Disease and Pest Control
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
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
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