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Volume 16, Number 3
Production Times is brought to
Lelan Parker, M.S.
Office: (407) 254-9200
FAX: (407) 850-5125
This material is provided as one of the many
services relating to the educational programs
offered to you by this agency. Our statewide
network of specialists is prepared to provide
current information on agriculture, marketing,
family and consumer sciences, 4-H, marine
science, and related fields. We will be happy to
help you with additional information upon
Use of trade names in this newsletter does not
reflect endorsement of the product by the
University of Florida, Institute of Food and
Agricultural Sciences, or the Florida Coopera-
tive Extension Service.
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NEWS FLASH: PLANT CLINIC
CHARGES & CHANGES!
Due to budget cuts at the University of Florida the Commercial Plant Diagnos-
tic Clinic at the Mid-Florida Research & Education Center (MREC) in Apopka
will no longer be held on Thursday afternoons or be free of charge for disease
diagnosis. The new time will be Tuesday from 1:00 p.m. to 4:00 p.m. beginning
July 1, 2009 and a fee of $40.00 per sample will be needed for disease analysis
and shipping to Gainesville. MREC will no longer be accepting samples for
laboratory disease analysis, however insect questions and others that may be
answered without laboratory testing will remain free of charge.
0 Websites to Check Out
On the University of Florida's Central Florida Extension Webpage you can view
videos and download information on some of our recent programs that you
may have missed this year.
The Virginia Cooperative Extension has updated the Nursery & Greenhouse
There are publications on Pest Management and Plant Growth Regulators.
Hillsborough County Extension has a fact sheet on increasing plant sells via the
PEST ALERT! Orchid Mealybug, Pseudococcus dendrobiorum Williams (Hemiptera: Pseu-
dococcidae) The University of Florida collected this specimen in March of this year in Gaines-
ville. It is the first finding in Florida and the Western Hemisphere. Adults and immatures are
grayish-pink in color. Wax filaments are present around the entire body with two or three pairs
of filaments at the tip of the abdomen which are slightly longer than the rest. Usually a patch of
white waxy secretion is present on orchid roots surrounding the mealybug. This mealybug
lives on the roots of orchids and attacks Ascoglossum sp., Cymbidium sp., Dendrobium sp., Pha-
laenopsis sp., Pholidota sp. and Promatocalpum species. Heavy infestations could cause death of
host plants as well as dieback. For more information go to:
Photo by Lyle Buss
(University of Florida)
The Institute of Food and Agncultural Science (IFAS) is an Equal Employment Opportunity Institution authonzed to provide research, educational information and other services only to individuals and institutions that
function without regard to race, color, sex, age, handicap or national ongin U S DEPARTMENT OF AGRICULTURE, FLORIDA COOPERATIVE EXTENSION SERVICE, UNIVERSITY OF FLORIDA, IFAS,
FLORIDA A & M UNIVERSITY COOPERATIVE EXTENSION PROGRAM, AND BOARDS OF COUNTY COMMISSIONERS COOPERATING
L J Mesophyll Cell Collapse of Orchids
By Lelan D. Parker
Mesophyll cell collapse is a physiological disorder that affects many different types of orchids. Ini-
tial symptoms show up as sunken yellow areas which later may turn dry and necrotic; damage is
permanent to the leaf. Injured leaves may become colonized with fungi that feeds on dead matter
which causes many growers to believe the disorder is fungal leading them to spray with unneces-
sary chemicals. This disorder can be caused by plant exposure to low water or air temperatures,
which damages mesophyll cells in the leaf. Just like freeze damage, mesophyll cell collapse may
take a significant length of time (6-8 weeks) for symptoms to appear. Thus, the condition is hard to
identify and many growers mistake it for a fungus and apply chemicals unnecessarily. The severity
of symptoms is related to factors such as temperature, length of exposure to low temperature and
the age of the leaves. Mature leaves appear to be resistant while younger leaves appear to be more
susceptible to injury. Mesophyll cell collapse occurs frequently in Phalaenopsis orchids because of
the thick, fleshy leaves. Phalaeonopsis insigne has relatively thin leaves and may not be as prone to
mesophyll cell collapse. A detailed history of growing conditions is needed for proper diagnosis.
For areas that are prone to drafts or lower temperatures, thermometers can be placed in the green-
house to record temperature variance. In some cases records of growing conditions may not be
available and a deeper examination of the plant to rule out pathogens as a cause of damage may be
required. If there are no viral, bacterial or fungal pathogens present then environmental stresses
may be the cause of the damage.
For more information go to: http://edis.ifas.ufl.edu/pdffiles/PP/PP26500.pdf
Pulp Mill Ash for Marigold Production
By Lelan D. Parker
The Mississippi State University experiment station conducted a trial evaluating the potential of
pulp mill boiler ash as an alternative substrate component for greenhouse production. Marigolds
were used as a test plant. Pulp mill boiler ash is a widely available industrial waste byproduct pro-
duced when the paper industry burns tree residues and other materials to fuel paper mill boilers.
Currently, the majority of this boiler ash is put into landfills, whereas some is applied to forest and
agricultural land. This study illustrated that there was no significant difference in N, K, and S con-
centration in shoots from plants grown in peat-based substrates with ash content. Plants grown in
all substrates containing ash had lower Mg, Zn, and Cu concentration in shoots; and plants grown in
20% to 50% ash had lower Mn concentrations. Increasing ash additions also led to lower Mn, Zn,
and B concentrations in shoots. It appears that paper mill boiler ash has the potential to be used as
an ingredient in peat-based substrates rather than as a sole substrate component. Proper testing
must be conducted before incorporating paper mill boiler ash into growing substrates.
For more detailed information on this study refer to: Use of Pulp Mill Ash as a Substrate Component
for Greenhouse Production of Marigold by G. Bi, W. B. Evans, and G. B. Fain. HortScience 44(1): 183-
SNew Cultivar: 'Emerald Bay' Aglaonema
'Golden Bay' Aglaonema was developed through the Foliage Plant Breeding Program at the U. F.
Mid-Florida Research & Education Center (MREC). 'Emerald Bay' Aglaonema originated as a muta-
tion from tissue cultured 'Golden Bay' Aglaonema plants. 'Emerald Bay' was selected because it
lacked the yellow background coloration present in normal 'Golden Bay' leaves and petioles.
'Emerald Bay' cuttings reach marketable size in 9 months. It readily adapts and performs well un-
der low light and humidity levels that are encountered in the interiorscape. Prior to installation in
an interior setting the plant does not require post production. 'Emerald Bay' is intended for com-
mercial producers growing finished plants in 6 or 8 inch pots. Plant patent rights have been as-
signed to the Florida Foundation Seed Producers.
'Golden Bay' Aglaonema 'Emerald Bay' Aglaonema
For more info go to: http://edis.ifas.ufl.edu/pdffiles/EP/EP35500.pdf
Plant Clinic Problem: Abiotic Disorders
Over the past quarter many of the plant clinic diagnoses have resulted in "no pathogen present".
Abiotic factors are the main cause of this result. Abiotic disorders are nonbiological factors that are
associated with the plant's environment. Environmental factors include soil pH, air quality, light,
temperature, moisture and nutrition. Abiotic disorders may also be caused by human contact, such
as fertilizer and pesticide applications. Environmental problems are more likely to affect most
plants in the environmental unit uniformly. Taking abiotic causes into consideration first may make
the identification process less time-consuming.
Liriope-Injury Aglaonema-Burn Bird's Nest Fern-Iron deficiency
For all plant clinic diagnosis go to: http://cfextension.ifas.ufl.edu/agriculture/plant_clinic/
M Upcoming Programs
25 Limited Pesticide License Certification Review and Exam. Tavares, FL See flyer inside to register.
Contact: Maggie Jarrell 352-343-4101.
1, 2 Small Farms Alternative Enterprises Conference. Kissimmee, FL. http://smallfarms.ifas.ufl.edu
4 Spanish IPM Nursery Scout Training. MREC Apopka, FL. Contact: Maggie Jarrell 352-343-4101.
19 Review and Exams for Restricted Use Ornamental/Turf or Private Agriculture Applicator Pesticide Li-
censes. Tavares, FL. See flyer inside to register. Contact: Maggie Jarrell 352-343-4101.
18 Green Industries Best Management Practices. Orlando, FL at Orange County Extension. To register con-
tact: Yamira Donato 407-254-9200.
Production Times is going green! Refer to form attached for details.