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Green-seeds.com:
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LANDSCAPE, FLORICULTURE, AND ORNAMENTALS NEWS
Hawaii Cooperative Extension Service
Volume 1, No. 2, December 1997
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CONTENTS
David Hensley, dhensley@hawaii.edu
Kenneth Leonhardt, leonhard@hawaii.edu
CTAHR Extension Horticulture Specialists
Last modified: September 1998
Kent Kobayashi, kentko@hawaii.edu
Dept. of Horticulture, CTAHR, Univ. of Hawaii
Floral Status of Malaysia and Mexico
Ken Leonhardt, leonhard@hawaii.edu
CTAHR Extension Horticulture Specialist
 FloraCulture International
is a trade magazine published by International Horticulture Publications
Co. of Batavia Illinois. It has often profiled a country whose floral industry
is emerging or undergoing significant change. Some of these events may impact
the floral industry in Hawaii and the U.S. at large. Some points that caught
my attention in two such articles are restated here in brief.
Malaysia: cut flowers' newest trade competitor, by Nancy Laws, February
1997.
Here it is pointed
out that floral exports have increased from $7 million in 1988 to $20 million
in 1994 , due in large part to government initiated policies intended to
bolster cut flower exports. A variety of tax incentives are available to
local and foreign investors. The government has supported growers participation
in international trade shows and exhibitions by covering travel and freight
costs, supports an overseas sales office, and brings in foreign consultants
with production and marketing expertise. Readily available construction
materials and good communication and transportation infrastructure are reasons
to expect continued industry growth.
Of interest to
Hawaii orchid growers is the government's ambition to increase orchid cut
flower production in the lowland state of Johor to over 2,900 hectares (7,200
acres) and, "replace Thailand as the major cut orchid producer in Asia."
Targeted markets include Singapore, Japan, Australia, Taiwan, Hong Kong,
and South Korea. Potted orchid production has not gone overlooked as several
Taiwanese phalaenopsis producers are expected to joint venture with Malaysian
producers this year.
Changes in Mexican floriculture, by Marta Pizano, June 1997.
This article reviews
production and marketing strengths and weaknesses of Mexico's cut flower
industry and identifies deficiencies that need to be overcome in order to
be more competitive in export markets. Mexico produces cut flowers on over
10,000 hectares (24,700 acres) of mostly open fields. Greenhouse production
is recorded at only 425 hectares (1050 acres). From this area, 15 million
tons of flowers were produced in 1994 of which approximately 90% was consumed
within the country during celebrations, holidays, and everyday life. Despite
NAFTA, suitable climate and geography, and a large and low cost labor force,
Mexico has not yet realized much of its potential as a flower exporter,
although the U.S. imported $24.6 million in flowers in 1995 which accounted
for over 90% of Mexico's flower exports. Rose, carnation and traditional
flowers make up the bulk, although modest and declining amounts of anthurium,
dendrobium orchid, and "other orchid" are listed.
The Mexican government
recognizes the industry shortcomings and has initiated technical and financial
programs to assist growers. Universities and research centers are said to
offer training and technical support. Many of these programs are coordinated
through several local, regional, and national organizations such as the
Mexican Flower Council. The need to improve crop culture including pest
and disease management, and postharvest management and infrastructure are
emphasized.
International Flower Bulb Center Now On-line
The International Flower Bulb Center Hillegom, The Netherlands, is
now on-line. In-depth information on trends and variety performance as well
as how-to information, news and feature stories and photographs are just
a few of the features offered.
1996 Netherlands Bulb Industry Statistics
9 billion bulbs produced annually
7 billion exported
4.55 billion to international growers of cut flowers and potted plants
2.45 billion to home gardeners worldwide
1 billion to U.S. gardeners
Source: Netherlands Flower Bulb Information Center, Brooklyn, NY
Special Local Need (SLN) Labelings for Agriculture
Chemicals in Hawaii
New. Plumerias; Monterey Florel® Brand Pistill (Lawn and Garden
Products; 264-263-54705); HI-960006 new 9/23/96-9/22/01. Promotes leaf drop.
Promotes winter flower production in warm climate.
Expired. Carnations; Plantvax® 75W (Uniroyal; 400-144); HI-810014
expired 2/13/97.
Source: The Pesticide Label, CTAHR Dept. of Environmental Biochemistry,
Jan-Feb 1997.
Hibiscus Mealybug
David Kuack, editor
GMPRO magazine
Florida flower and foliage growers may soon have a new pest to deal
with: Hibiscus mealybug, Maconel-licoccus hirsutus, is traveling through
the Caribbean toward Florida, said Univ. of Florida entomologist Lance Osborne.
The insect has put growers out of business and wiped out entire forests
in other countries. It has hundreds of ornamental plant hosts: hibiscus,
chrysanthemum, allamanda, begonia, ficus, palms, poinsettia and pothos.
Osborne said arrival of the mealybug is inevitable and could come into Florida
on imported plant material or be carried by a hurricane.
About Research
Eileen Herring, eherring@hawaii.edu
Science Librarian, Hamilton Library
Effects of six fertilizers on vegetative growth and flowering of phalaenopsis
orchids. Wang, Y.T. 1996. Scientia Horticulturae 65 (23):191-197.
Six water-soluble
fertilizers were applied at two different concentrations to young seedlings
of Phalaenopsis Tam Butterfly. After seven months, leaf span, leaf size,
total leaf area, and shoot and root fresh weight were measured. No differences
were found between the various fertilizers at either concentration. The
higher concentration application (200 ppm) for all fertilizers produced
wider leaf spread, more and larger leaves, and greater total leaf areas.
This study suggests that if Phalaenopsis orchids are grown in media having
good moisture and nutrient retention capacity, any balanced fertilizer will
produce good growth. Since flowering is directly related to leaf production
and expansion, higher fertilizer rates are suggested to produce rapid growth
in young plants. Fertilizer concentrations can be reduced for mature plants
in order to avoid producing excessively large plants which increases production
costs.
Testing the light acclimatization potential of Chrysalidocarpus lutescens
Wendl. Reyes, T., T.A. Nell, J.E. Barrett and C.A. Conover. 1996. HortScience
31(7): 1203-1206.
Areca palm (Chrysalidocarpus
lutescens Wendl.) performance as low light interior plants was evaluated
by using varying production light and fertilizer levels for 8 months, then
placing the plants in interior conditions for 3 months and measuring the
light compensation point, chlorophyll concentration and carbohydrate reserves.
Three light levels (481, 820 and 1231 mmol/m 2 /s) were combined with three
application rates of 201020 fertilizer (0.015, 0.03 and 0.06 oz/2 gal pot
or 440, 880, and 1660 mg/6.25 L pot). The interior conditions tested were
20 mmol/m2/s for 12 hours daily at 70oF (21oC) and a relative humidity of
50%. Previous studies have shown that plants which adapt well to low light
interior conditions exhibit anatomical and physiological changes during
exposure to low light levels which result in lower light compensation points
and higher chlorophyll concentrations. In this study, regardless of the
production treatments used, areca palms did not exhibit these adaptations
to low light and instead used internal carbohydrate reserves for growth.
For this reason, areca palm is not recommended for extended interior use
under the low light levels characteristic of most homes and commercial spaces.
Root distribution of six palm species grown in cupric hydroxide-treated
containers. S.E. Svenson and T.K. Borschat. Fort Lauderdale Res. and Edu.
Center, Univ. of Florida, 3205 College Ave., Fort Lauderdale, FL.
The root distribution
of seedlings of Acoelorrhaphewrightii, Carpentaria acuminata, Chrysalidocarpus
lutescens, Livistona chinensis, Phoenix roebellenii, and Washingtonia robusta
were grown in nontreated containers of in containers treated on their interior
surfaces treated with 25, 50, or 100 g/liter copper hydroxide. Seedlings
of all species grown in treated containers had reduced circling or matted
roots at the container wall-growing medium interface. The distribution of
roots was specific and was significantly influenced by the rate of copper
hydroxide. Copper treatment did not induce visual signs of copper toxicity,
not differences in shoot growth, nor differences in the number of higher-order
lateral roots.
Performance of
nitrate N fertilizers on bermuda grass in humid tropical conditions. M.D.
Hamilton, F. Cruz, and J. McConnell. College of Agriculture and Life Sci.,
Univ. Guam, UOG Station, Mangilao, Guam.
The performance
and leaching of six nitrogen fertilizers on bermudagrass was studied under
humid tropical conditions. Ammonium nitrate was applied to the turf monthly
at rates between 0.25 and 6 lb/1000 sq ft. Performance was gauged on clipping
dry weights, color evaluation, and visual ratings. Leachates were checked
for nitrate levels. A rate of 2 lb/1000 sq ft produced quality turf while
yielding a minimum of nitrate leaching. Rates of 4 and 6 lb/month resulted
in the highest nitrate leachings without an increase in quality. Rates of
less than 2 lb had less than 9 ppm nitrate leachate, but produced unacceptable
quality. Nutralene, Nitroform, sulfur coated urea, IBDU, and ammonium nitrate
were applied at 2 lb/1000 sq ft/month. Slow release forms were applied as
a 3 month dose. Nutralene, SCU, and Nitroform had peak nitrate leaching
levels 2 weeks after application. IBDU had peak nitrate levels after 4 weeks.
Turf quality diminished at 6 weeks.
Think About Gypsum Before Spending Your Money
Gypsum is often advertised as the magic bullet to improve the structure
of clay soil. This is not necessarily true. Any improvement in soil structure
from gypsum only occurs when there is much more sodium than calcium in the
soil. In Hawaii, we do have some soils with high levels of sodium and applying
gypsum may help in those cases.
On soils that are not high in sodium, the gypsum does little good.
Instead, consider aerifying and top dressing with compost. Aerify with large
tines and punch 20 to 40 holes per square foot. Top dress with a mature
compost and rake or drag in.
Tree Selector Computer Program Available
A program to aid in selecting tropical trees is now available. This
program is designed to work on Macintosh computers using HyperCard. It provides
information on several trees in Hawaii and recommends trees based on user
specified criteria. The text of the information was adapted from How to
Select a Tree and How to Plant a Tree by Mary Young, Honolulu Botanic Garden.
The program is part of the Farmer' Bookshelf developed by Kent Kobayashi
and Skip Bittenbender. The tree selector was adapted to the Farmer's Bookshelf
series by Kim Oshiro, David Hensley, and Julie Yogi, Department of Horticulture,
CTAHR. This program does not run on DOS or Windows machines.
If you would like to obtain a free copy of the Tree Selector for Macintosh,
contact David Hensley, Department of Horticulture, UHM, 3190 Maile Way,
St. John 102, Honolulu, HI 96822-2279. Ph. 808-956-2150. E-mail: dhensley@hawaii.edu.
Dendrobium Icy Pink 'Sakura'
H. Kamemoto, haruyuki@hawaii.edu,
A. R. Kuehnle, heidi@hawaii.edu, T.
D. Amore, and N. C. Sugii
CTAHR Dept. of Horticulture
A new Dendrobium flower color, Icy Pink, was first encountered in
our breeding program in 1977 from across between a two tone lavender D.
Jaquelyn Thomas, O580-4N, and a white D. phalaenopsis, K43-14. One offspring,
K360-8, produced a pale pink flower among other siblings with two tone lavender
flowers. K360-8 was then crossed to tetraploid D. phalaenopsis, W15-6. Among
the offspring, K816-32 produced tinged flowers that were slightly darker
pink than the K360-8 parent. Subsequently, K816-32 was self pollinated with
the objective of obtaining an even darker pink tinged flower.D. Icy Pink
'Sakura' (K1224-6) was the result.
K1224-6 appeared to possess some desirable qualities for commercial
cut flower production, and therefore was micropropagated for further observation
and evaluation in glasshouse and saranhouse environments. The performance
of the majority of characteristics were better for plants grown in the glasshouse
(Table 1).
Table 1. Characteristics of K1224-6 in glasshouse and
saranhouse.
Characteristics Glasshouse
Saranhouse
Flower width (in) 2.9 ±
0.5 2.4 ± 0.6**z
Pedicel length (in) 2.3 ± 0.4
2.6 ± 0.7**
No. flowers per spray 14.7 ± 1.7
12.8 ± 1.4**
Scape length (in) 7.9 ±
1.2 8.2 ± 0.9 ns
Raceme length (in) 23.3 ± 5.5
19.4 ± 4.1**
% bud drop
0.78 ± 2.1 1.7 ± 2.3**
% sprays with bud drop 6.5 ± 11.5 13.5
± 15.9**
No. sprays per plant 10.9 ± 2.3
8.7 ± 3.0**
Pseudobulb height (in) 35.8 ± 5.9 30.4
± 6.3**
z ** significantly different at 99% level; ns - not significant
The desirable features of K1224-6 are:
- New, attractive, delicate icy pink flowers (RHSCC54D for tepals,
54C for lip). This color was recently identified chemically as pelargonidin,
an anthocyanidin that differs from the cyanidins occurring in lavender-purple
flowers.
- Flowers are slightly larger and fuller than those of amphidiploid
cut flower cultivars.
- Sprays are long with long scapes.
- It is relatively free of bud drop.
- Good vase life. The half-life of cut sprays was about 20 days. Even
those harvested at a young stage, when only half of the flowers on the
spray were open, kept nearly as well as those harvested at two-thirds
to three-quarters maturity.
- Flower yield was moderate and distributed throughout most of the
year (Table 2). As the plants matured, the yields increased.
Table 2. Monthly spray yields of K1224-6 in glasshouse (G2) and
saranhouse (S), based on 47 plants in glasshouse and 57 plants in
saranhouse.
1994
1995 1996
TOTAL
G2 S
G2 S G2
S G2 S
JAN 8 15 21
9 29 24
FEB 9 13
8 19 17 32
MAR 11 19 7
4 18 23
APR 6 3
5 7 11 10
MAY 4 3
11 13 15 16
JUN 2 2
18 6 20
8
JUL 0 2
6 18 6 20
AUG 6 9
6 3 38 66
50 78
SEP 15 25 12
15 29 52 56
92
OCT 13 26 45
48 106 57 164 131
NOV 6 9
45 0 42 20
93 29
DEC 2 6
10 0 14 40
26 46
TOTAL 42 75 158 123
305 311 505 509
The undesirable feature of K1224-6 is the long, droopy sprays, especially
when sprays are kept beyond the three fourths maturity stage. This problem
can be alleviated by harvesting sprays when only 50% of the flowers are
open.
Because of the unique and attractive "new" dendrobium color, the parent
of K1224-6 is being registered as Dendrobium Icy Pink. By the rules of orchid
nomenclature any offspring resulting from selfing the parent, K816-32, must
retain the same name; hence the progeny K1224 must also be called D. Icy
Pink. Since K1224-6 is a clone, Sakura (cherry blossom) was chosen as the
cultivar name.
Root Mealybugs
Arnold H. Hara, arnold@hawaii.edu
CTAHR Dept. of Entomology, Hilo
Root mealybugs
occur only on roots of their host plants. Because they are undetected, occurring
below-ground, root mealybugs can be a serious pest. Currently, the Hawaiian
Islands have 7 species of root or hypogaeic mealybugs. The most pestiferous
species have been the coffee root mealybug, Geococcus coffeae, and Rhizoecus
hibisci. Plant host range of these root mealybugs are very wide, infesting
grasses, palms, citrus, cyperus, pineapple, coffee, mango and syngonium.
In pots, root
mealybugs occur throughout the root mass; however, they are concentrated
between the root-ball and the pot. Infestations of root mealybugs are noticeable
only if the root-ball is removed from the pot. The white waxy material is
the most important sign of root mealybug infestation. Mealybugs secrete
lots of white waxy material that covers their bodies. Female mealybugs lay
eggs or give birth to live young (crawlers).If eggs are laid, they usually
hatch in less than 24 hours. Crawlers are the dispersal stage and are highly
mobile. Once the crawlers find a suitable site, they settle down and begin
to feed on roots with their sucking mouthparts. The entire life cycle ranges
from 2-4 months depending on the species. Adults live from 27-57 days, also
depending on species.
Prevention
Because the root mealybug is very difficult to control, every effort
should be made to prevent spread and establishment. The following practices
are recommended to prevent spread and establishment:
- Inspect roots of newly purchased plants for root mealybugs by removing
the pot.
- Avoid root-bound plants by re-potting as needed; root-bound plants
encourage mealybugs.
- Use clean pots and media; if infested wash with soap and water.
- Treat or remove infested plant hosts from your premises.
- Do not allow water from infested areas to drain into clean areas;
crawlers can be transported in water.
Control
Research by the University of Hawaii, CTAHR, has demonstrated that
insecticides and/or a hot water dip are effective treatments. Dursban WP
applied as a liquid drench and Marathon G are effective against root mealybug.
Watering plants prior to drench application will significantly reduce problems
with phytotoxicity. Consult the Cooperative Extension Service, Hawaii Department
of Agriculture or a reputable agrochemical professional for a specific product
registered for use. Submerging potted Rhapis palms in 120° F (49°
C) hot water until the internal root ball temperature reaches 115° F(46°
C) is 100% effective in killing root mealybugs. Hot water at 120° F
does not significantly affect potted Rhapispalms.
For more information or a detailed report contact Arnold Hara in Hilo
at Ph: (808) 974-4105, Fax: (808) 974-4110 or e-mail: arnold@hawaii.edu.
Fungal Disease Control of Orchids
Ken Leonhardt, leonhard@hawaii.eduand
Wayne Nishijima, waynen@hawaii.edu
CTAHR Extension Specialists
This is a favorable
time of the year for fungal diseases on orchids. Transmission of fungal
spores is usually by wind, water, contaminated equipment and plant parts,
and occasionally carried by insects and nematodes. Rain and high humidity
conditions contribute to fungal spore germination and infection.
Fungal diseases
of orchids include flower and foliar spots and blights, pseudostem and root
rots, and damping-off of seedlings.
The first level
of defense is to start out with pathogen-free planting material and employ
high levels of sanitation in all cultural practices. This includes removal
of dead and infected plant parts including fallen leaves which can be a
source of innoculum. Use new pots or disinfest pots to be reused. Always
use clean new media. Orchid media should be very well drained and freely
aerated. When an organic medium breaks down water retention becomes excessive
and aeration inadequate. Fungal diseases of the root system are almost certain
to follow. Flame or surface disinfest tools that come in contact with plant
tissues.
Irrigate plants early
in the day to allow for leaves to be dry at night. Ensure that greenhouses
have adequate ventilation and/or air circulation to minimize still, humid
conditions that are favorable to disease development. Inspect roofs and
gutters to ensure that there are no leaks that might splash onto plants.
Fungicides can
be used to prevent infection. Proper equipment calibration and fungicide
application are essential. Follow application instructions and precautions
on the bag. The following is a list of fungicides available for use by orchid
growers in Hawaii.
Fungicides for Orchids
(Prepared Nov.
14, 1997) Disclaimer: This list was prepared as a guide for general use
by orchid growers in Hawaii. Because of frequent changes to registrations,
this list may be inaccurate. Always consult the label for proper use and
registration of the fungicide. Current registrations can be found on the
World Wide Web
Crop registered under/Fungicide Type*
Remarks
*P=Preventive; C=Curative
Dendrobium
Bayleton 25 T/O
P/C Fusarium, anthracnose, others
Dithane F-45, M-45 DF, WF; Fore, Fore
Flowable; Manzate 200
P Mancozeb; all fungi
Metam, Vapam, Nemasol
n/a General-purpose soil and
media fumigant
Ornalin Contact Fungicide
P/C Botrytis; contact
Orchids
Turban, Terrazole
P Phytophthora and pythium
Flowers
Aliette WDG Fungicide
P/C Phytophthora and pythium
Bayleton 25 T&O
P/C Fusarium, anthracnose,
others
Botran 75W Fungicide
P Botrytis
Champion WP, Kocide LF
P Copper hydroxide
Clearys 3336 G, WP; Domain FL;
Fungo Flo,
P/C Botrytis, anthracnose,
phyllosticta, others
Cooke Daconil Lawn & Garden, Ortho
Daconil 2787
P Most fungi
Ford's Procide Systemic
P/C
Metam, Vapam, Nemasol
n/a General-purpose soil and
media fumigant
Protect T&O
P Mancozeb; most fungi
Rubigan 50WSP, EC
P Botrytis
Subdue 5G
P/C Phytophthora and pythium
Terraclor 400 Flowable Ornamental Soil
Fungicide; Turfcide 10% Granular T&O;
Revere
P Rhizoctonia, sclerotium,
etc.
Ornamentals
Banner
P/C Rhizoctonia, anthracnose
Chipco 26019
P Many fungi
Clorox
n/a Disinfestant, benches,
etc.
Metam, Vapam, Nemasol
n/a General purpose soil and
media fumigant
PT 2000 Greenshield
P General purpose
disinfectant
Rubigan EC
P Botrytis
Terraguard
P/C Rhizoctonia,
cylindrocladium, other
fungi
Triathlon
n/a General purpose
disinfectant
Look at Maintenance Before Planting
David Hensley, dhensley@hawaii.edu
Extension Landscape Specialist
CTAHR Department of Horticulture
Did you know that
much more money is spent maintaining a landscape than on planning, designing,
the plants, and contract installation combined? Evaluating a proposed design
for "maintainability" before it is installed will save money and time. Eliminate
maintenance problems before they are installed and reduce the frustration
level of the people that must keep up with the demands of a poorly planned
landscape.
Look for problems
on site and planting plans and correct them before they come back to haunt
the designer, the contractor, the maintenance personnel, the owner, and
the property manager. Consider these changes to sites to save headaches.
- Avoid turf strips that are narrower than one and one-hal times the
width of the smallest mower or the mower used in that area.
- Change small enclosed areas of turf that are hard to reach with a
mower.
- Eliminate small needless turf areas (that aren't walked on) scattered
throughout the site. Fill these with groundcovers, flowers, or mulch.
- Smooth bed lines to eliminate tight curves and squiggles that will
be difficult to mow and edge.
- Do not plant low-branching trees in small turf areas unless you plan
for a mulch ring to prevent trimming.
- Incorporate obstacles (lights, signs, poles, etc.) into planting
beds rather than in the middle of the lawn area. Use mulch rings or
mowing strips around those items in the turf to eliminate trimming.
- Make sure that signs are not obstructed by low branched trees, large
shrubs, or other plantings.
- Keep benches and other site furniture located in convenient locations
for users. Are benches in safe locations? Are they in open, visible
spots or are they in areas hidden by dense plantings?
- Are the plants in parking lots appropriate? Will they soon be encroaching
into the parking spaces or have to be trimmed continually? Do they block
visibility?
- Give plants room to grow. Do not jam too many plants just to make
the beds look full. Give shrubs in beds about one-half of the natural
spread to grow, and pruning and pest problems are reduced.
- Make sure trees have adequate space around the roots and select trees
carefully. A 4 foot by 4 foot square cut in a walk or parking lot will
not accommodate a large-growing shade tree. The street, wall, or curb
will buckle eventually.
- Eliminate individual shrubs spotted around the lawn areas. The shrubs
are maintenance intensive and also visually distracting. Every plant
needs a reason to be where it is.
Copper Hydroxide Repels Slugs
Arnold H. Hara
CTAHR Dept. Of Entomology, Hilo, Hawaii
Copper hydroxide is usually used as a fungicide, but also formulated
as a root growth regulator that prevents root-bound containers. Recently,
CTAHR discovered that the copper hydroxide coating is very repellent to
the two-striped slug, Vernoicella cubensis. Plastic pots, grow bags, and
weed mats coated with a special formulation of copper hydroxide significantly
repelled slugs. For example, in one test, pots were placed in a contained
area (15 sq ft) with 500 slugs; copper hydroxide coated pots harbored an
average of 0 slugs per plot, while uncoated pots harbored an average of
24 slugs per pot.
Presently, copper hydroxide coated products are NOT registered for
use as a molluscicide, but registered only as a root growth regulator
For more information or a detailed report, contact Arnold Hara in
Hilo at Ph. (808) 974-4105, Fax: (808) 974-4110 or e-mail: arnold@hawaii.edu.
A Technique for Acclimatizing Plants from
Tissue Culture
Susan P. Martin1, Carol A. Bobisud1, and Terry T. Sekioka2, terry@hawaii.edu
1Research Associate, 2Kauai CES Administrator
Tissue culture
plantlets sometimes do not survive when transferred out of the vessel into
harsher greenhouse environments. Major changes involve humidity, light,
nutrient source and the presence of pathogens. Plantlets in the flak range
from larger to smaller, weaker plantlets. Many times, it is the smaller,
weaker plant that dies.
A technique to
increase the changes of survival of these plants has been developed by our
laboratory. A "terrarium-like" plastic bubble is used to acclimatize and
growth the plants from the flask prior to transferring to the greenhouse.
Presently, the technique used to step-acclimatize the small cultured plants
is in a plastic bag of moisten sphagnum. After the plantlets are planted,
a mist of water is sprayed into the plastic bag. Air is blown into the bag
to form a big bubble, and the opening of the bag is twisted and taped closed.
Bags of plants are then placed on illuminated shelves. Plants are kept in
this bag until they are of adequate size and/or hardiness is attained.
Three experiments
were conducted to investigate suitable planting media for this technique.
Plants used were pineapples clones t-132, t-0, t-155, and ttl-8, all obtained
from the USDA ARS Plant Germplasm Repository, Hilo, Hawaii. Potting media
used were perlite, sphagnum, and peat-lite in experiments 1 and 2; sphagnum,
peat, and a vermiculite-perlite mixture were used in experiment 3. A random
sampling of 50 plants were selected for each bag of medium. There were 3
treatments with 3 bags per treatment for each experiment. Fresh weight of
the plans was taken before and after the growth period of the experiment.
Dry weight was also recorded at the end of the experiment as was the number
of surviving plants in each bag.
Because of small
numbers of data and the non-normality of the data, the analysis of variance
was not utilized. Means were evaluated. It appeared that in all of the experiments
perlite or a perlite-vermiculite mixture was a poorer medium for plant growth,
but not necessarily for survival. This could be because it is not as good
a nutrient source. Survival may be more dependent upon factors other than
medium (such as moisture in the bag, size of the plants, etc.). Peat, sphagnum,
or a peat-lite medium all showed to be adequate and suitable media for growth
using this technique. The advantage of this technique is the higher survival
percentage of the smaller, weaker plants in the transition from the flask
to pot. However, the additional step of planting in the plastic bag prior
to planting in pots requires a longer time interval.
Mulch is a Tool
David Hensley, dhensley@hawaii.edu
Landscape Extension Specialist
CTAHR Department of Horticulture
In landscape maintenance,
mulch is a tool to be used by professionals. It is as important as a mower
or a pruner in keeping the plants healthy and for reducing labor. Mulch
reduces water loss, controls weeds, moderates soil temperatures, and reduces
soil compaction. Some of us, however, forget how many landscape maintenance
problems can be solved by mulching.
Mulch is any material
used to cover the soil. I prefer organic mulches (bark or compost) to inorganic
materials such as stone. While inorganic mulches provide the same benefits
and do not require periodic replacement, they do nothing to improve the
soil. Organic mulches break down yield humus that improves the soil's physical
and chemical properties. Organic mulches appear more natural and less formal
than stone. Organic mulches, however, must be replenished annually.
Mulching a planting
bed with 3 inches of a quality mulch reduces weed growth by up to 90 percent.
Budget limitations sometimes reduce the amount of mulch that is actually
applied and may limit the amount replaced. This is "voodoo economics." It
saves a little money up front and spends more than saved later to remove
weeds and deal with problems. The owner will be money ahead to spend the
amount needed for organic material to be incorporated into the bed and used
as a mulch. Unfortunately, most maintenance people have little say in this.
Replacing the
grass and soil around a tree, sign, or other objects in the lawn with mulch
eliminates trimming and speeds mowing. Creating a mulch barrier around trees
also protects them from string "trimmeritus."
Organic mulch
can be used as a construction cushion when the landscape or turf must be
crossed with heavy equipment. The layer of organic mulch cushions the soil
and greatly reduces compaction. The mulch can be tilled in as a soil amendment
when replanting the turf or landscape after construction.
Mulching is a
very cost effective means of conserving water. Mulching is one of the basic
tenents of Xeriscaping. It eliminates water loss through evaporation and
by preventing competing weeds. Water percolation into the soil is improved
by the mulch so greater benefit is received from irrigation.
Organic mulches
are not fertilizers, however. Organic mulches provide a small amount of
minor nutrients as they break down, but do not supply significant amounts
of nitrogen, phosphorus, potassium, or other major nutrients. In fact, organic
mulches can compete for nitrogen with landscape plants. The organisms that
breakdown organic matter need nitrogen to grow and live. The microbes are
more efficient nitrogen scavengers than trees and shrubs. This is not a
problem unless (1) the fertility of the site is very low and there is no
fertilizer program to supply nitrogen, or (2) if the mulch is "raw" or will
decompose rapidly. I have seen nitrogen deficiency symptoms when raw or
uncomposted bark or sawdust is used.
Mulches are a
valuable resource and tool for the professional landscape manager. Select
and use them to reduce labor and save money.
Organic Landscape Mulches
Replacement
life
(seasons)
Availability Notes
Leaves <1
high Unattractive,
tend to mat, can
harbor mice, blow, and be a fire
hazard. Longevity depends on species
but all are short.
Manure <1
med. to Not in my landscape! Source
of
high weeds and odor
unless composted.
Composted manure makes a high
quality pleasing mulch.
Lawn 1
high Unsightly, smelly,
pack and tend to
clippings
repel water, can damage tender
plants during decomposition and
because of herbicide residues.
Shredded 1-2
high Usually excellent
and preferred
bark
material--texture depends on
processing, color goes to dark brown
or gray with time; select composted
material if possible; fir, redwood
last several seasons; pine can
float. Hardwood bark also works
well.
Sawdust or 1
medium Will require additional
nitrogen
shavings
unless composted or "fortified". Can
float and blow. Redwood sawdust
common as an amendment and lasts
longer.
Pine 1-2
medium Widely used in South. Medium
to fine
needles
texture, brown color. Acid.
Peat moss 1-2
high Expensive as
a mulch! Can float.
Fine texture, brown color. Holds a
lot of water--avoid in wet areas.
Some Sources of Horticultural Books, Videos, and
Software
Write, phone, or fax for free catalogs. Please let us now of others--thanks.
A.C. Burke & Co. 2554 Lincoln Blvd., Suite 1058, Marina Del Rey,
CA 90291. Ph. (310) 574-2770, Fax (310) 574-2771.
American Nurseryman. 77 W. Washington St., Suite 2100, Chicago, IL
60602-2904. Ph. (800) 621-5727, Fax (312) 782-3232.
Ball Publishing. P.O. Box 247, St. Charles, IL 60174-0247. Ph. (888)
888-0013, Fax (888) 888-00014.
C&P Press, Inc. 888 Seventh Avenue, 28th floor, New York, NY 10106.
Ph. (212) 621-4601, Fax (212) 399-1122.
Creative Educational Video. 1020 SE Loop 289, Lubbock, TX 79404. Ph.
(800) 922-9965, Fax (800) 243-6398.
Edward R. Hamilton Bargain Books. P.O. Box 5005, Falls Village, CT
06031-5005.
Forestry Suppliers, Inc. P.O. Box 8397, Jackson, MS 33284-8397. Ph.
(800) 647-5398, Fax (800) 543-4203.
Grower Talks Bookshelf. 415 Bennett Rd., Elk Grove Village, IL 60007.
Ph. (888) 888-0013, Fax (888) 888-0014.
Iowa State University Press. 2121 S. State Ave., Ames, IA 50014-8300.
Ph. (800) 862-6657, Fax (515) 292-3348.
Prentice Hall. One Lake St., Upper Saddle River, NJ 07458, Fax (201)
236-7758.
San Lius Video Publishing. P.O. Box 6715, Los Osos, CA 93412. Ph.
(805) 528-8322, Fax (805) 528-7727.
The Haworth Press, Inc. 10 Alice St., Binghamton, NY 13905-1580. Ph.
(800) 342-9678, Fax (800) 895-0582.
Thompson Publications. P.O. Box 9335, Fresno, CA 93791. Ph. (209)
435-2163, Fax (209) 435-8319.
Timber Press. 133 S.W. Second Ave., Suite 450, Portland, OR 97204.
Ph. (800) 327-5680, Fax (503) 227-3070.
New CTAHR Publications
Dale Evans
CTAHR Editor
A new group of
publications for the landscape industry began with Selecting a tree care
professional (Landscape category publication L-1). Two other titles in the
series are Watering trees (L-2) and Mulching for healthier landscape trees
(L-3). These publications are designed to be of interest to homeowners as
well as landscape professionals.
Some technical
publications written for professionals in the landscape, ornamentals, and
floriculture industries are include n the CTAHR publication category Horticulture
Research Notes. Two recent titles are Substitutions for peat in Hawaii nursery
production (HRN-11) and Substituting Hawaiian composts for peat in growing
media for hibiscus (HRN-12).
These new publications
are available on-line at the website and go to "Publications."
Also, quite a
few of the Ornamentals and Flowers fact sheets on plants useful for landscapes,
including native Hawaiian species, have been revised during the past year.
The most current versions are available to be downloaded from the website.
The subjects covered include wiliwili, Kauai white hibiscus, naio, ohia
lehua, ma'o (Hawaiian cotton), aalii, hala, southern magnolia, wedelia,
beach naupaka, Oahu white hibiscus, akia, hapuu (Hawaiian tree fern), monstera,
oleander, ruellia, coromandel, hemigraphs, and bamboo.
New or revised
CTAHR fact sheets are often posted on the website before printed versions
become available.
Selecting a Tree Care Professional, Landscape, L-1,
April 1997
Ginny Meade and David L. Hensley, dhensley@hawaii.edu
CTAHR Department of Horticulture
Homeowners, property
managers, and everyone working with plants can greatly extend the life and
health of trees by practicing good gardening and maintenance techniques.
Some tree maintenance jobs, however, are best handle by professionals.
Arborists are
specialists in the care of individual trees. Arborists have the proper equipment,
skills, and training to do work in large trees, around power lines, and
at heights. Hiring an arborist should be a careful and detailed procedure.
Safe and proper tree care is important not only as an investment but to
minimize injuries and liability and extend the use and beauty of trees.
How do you select a
qualified arborist? Anyone can trim trees. Qualified and trained arborists,
however, follow a set of professional, legal, and ethical guidelines.
- Verify that the tree company is licensed. In Hawaii, arborists should
hold a C-27 B license.
- Ask if there is an International Society of Arborists (ISA)-certified
arborist in the company, and whether the tree workers are certified
by ISA. Voluntary certification or arborists is self-regulated to maintain
standards of competence and up-to-date knowledge in the science and
art of tree care. Certified arborists and tree workers must pass written
and field tests to prove their knowledge and skills.
- Ask for proof of insurance. Insurance should include personal and
property damage coverage, as well as workers' compensation. General
liability coverage should be no less than $1 million per occurrence.
Hiring underinsured or uninsured workers could result in your personal
responsibility for damages and injuries.
- Request references from other, similar work done by the company.
Always check the references and when possible, visit some of those sites.
This is an important step. Would you buy a car sight unseen?
- Unless you know or are comfortable with the arborist or the company,
get more than one estimate. Do not always take the low bid. Check the
credentials and the written specifications accompanying the bid or estimate.
Determine the best combination of price, work to be done, skill, and
professionalism.
- Get it in writing. There should be a written, detailed contract specifying
the work to be done and the cost. It is wise to include start and completion
dates. Determine who is responsible for cleanup and disposal. Ascertain
that the company has the proper tools and manpower to complete the job.
Ask other questions.
Use caution and common
sense. Be wary of door-to-door bargains for tree work. Most professionals
will not operate on this basis, and choosing a nonprofessional can prove
costly, dangerous, and ugly. Insist on proper and approved techniques. Some
examples of unacceptable practices are tree topping, excess removal of live
wood, removing or disfiguring living trees without good cause.
Invest some initial time before you spend money to be sure you obtain
the best possible care for your tees. The result will be trees that are
healthy, long-living, and increasingly valuable.
This newsletter is produced
in the Department of Horticulture, a unit of the College of Tropical Agriculture
and Human Resources (CTAHR), University of Hawaii at Manoa, as a participant
in the Cooperative Extension Service of the U.S. Department of Agriculture.
CTAHR is Hawaii's Land Grant institution established in 1907 from which
the University of Hawaii developed. For information on CES horticulture
programs or to receive future issues of this newsletter, please contact:
David Hensley or Kenneth Leonhardt
Department of Horticulture, University of Hawaii
3190 Maile Way, St. John 102
Honolulu, HI 96822-2279
Mention of a trademark, company, or proprietary name does not
constitute an endorsement, guarantee, or warranty by the University of
Hawaii Cooperative Extension Service or its employees and does not imply
recommendation to the exclusion of other suitable products or companies.
Caution: Pesticide use is governed by state and federal regulations.
Read the pesticide label to ensure that the intended use is included on
it, and follow label directions.
Thank You. We hope you've enjoyed this issue of Landscape, Floriculture,
and Ornamentals News.
David L. Hensley, dhensley@hawaii.edu
Kenneth W. Leonhardt, leonhard@hawaii.edu
Extension Specialists in Horticulture
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Green - Seeds Co., Ltd.
81/10B Ho Van Hue Street, Phu Nhuan District, Ward 9, Ho Chi Minh City, Vietnam
Tel: +84 (8) 847 6901 - Fax: +84 (8) 844 1392 - Email: info@green-seeds.com
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