Microsoft word - may 12, 2006 greenhouse ipm report.doc

Greenhouse TPM/IPM Weekly Report
University of Maryland Cooperative Extension
Central Maryland Research and Education Center

From: Stanton Gill and Ethel Dutky, University of Maryland Cooperative Extension
Ginny Rosenkranz, Extension Educator, Chuck Schuster, Extension Educator, Suzanne Klick
and Shannon Wadkins, Technicians, University of Maryland Cooperative Extension
Amanda Laudwein, Joanne Lutz, John Speaker, and Marie Rojas (Independent IPM Scouts)

May 12, 2006
Sclerotinia
We had a grower find Sclerotinia on their petunia crop this week. Ethel Dutky notes that
normally greenhouse growers don't spray greenhouse crops for this disease because the spore
inoculum comes in from clover and other forage fields so infection of the greenhouse crop is
scattered and sporadic. It is very important to rogue out infected plants. Once symptoms of
blight and canker, diagnostic signs of white fluffly mycelium (giving rise to the common name
"White Mold") and the distinctive black sclerotia are present it is too late to use fungicides.
Controls: Remove blighted plant parts. Vorlan (vinclozolin), Chipco 26019 (iprodione), Fore,
Zyban, and Protect T/O (mancozeb), Daconil Ultrex, Concorde, and Spectro 90 (chlorothalonil),
Spectro 90, Cleary's 3336, Zyban, TopsinM, and FungoFlo (thiophanate-methyl), Banner Maxx
(propiconazole), Terraguard (triflumizole), Terraclor (Pentachloronitrobenzene)

White peach scale (Pseudaulacaspis prunicola) is an armored
scale we usually find on temperate grown woody plants but it was
found this month on a shipment of plants that arrived from
Florida. The picture shows white peach scale found on oleander.
This armored scale is best controlled by applications of Distance
and 1- 0.5% horticultural oil applied right after crawler
emergence.

Brown soft scale (Coccus hesperidum) feeds on a wide range of greenhouse grown plants and
tropical foliage plants. It can be found on agave, gardenia, ficus, peperomia, schefflera, vinca,
yucca, ferns and several species of palms. This soft scale feeds in the phloem of the plant and
produces copious amounts of honeydew that coats plant foliage. Sooty mold will often grow on
the honeydew. The females are usually what you find on plants; males are rather rare. The
females are light brown, oval and generally flattened in profile.
Control: Systemic neonicotinoids applied to the soil
The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by Maryland Cooperative Extension is implied. Read labels carefully before applying any pesticides. Photographs are by Suzanne Klick, Stanton Gill and Shannon Wadkins unless stated otherwise. Tomatoes
We had two tomato samples in our lab this week showing symptoms of low fertility. Tomatoes
are often grown dry to keep them from stretching. The problem with this method of growth
regulation is that withholding water also means withholding nutrients. Soil tests confirmed that
the soluble salt levels on both samples were very low. A tissue analysis performed on the sample
shown on the left revealed low levels of potassium. Although a foliar analysis was not
performed on the sample shown on the right, the marginal scorching seen on the older leaves is a
classic symptom of potassium deficiency. The pH of the sample on the left was also low. Low
pH makes iron in the soil more soluble and available to the plants. Tomatoes are an iron-
sensitive crop. Excess iron could also have caused the spotting seen on the leaves.
.

Morning Glories
In The Washington Post on May 3, 2006, there was an article by Theresa Vargas on the increased
use by teenagers of morning glory seeds as a hallucinogen when ingested. The seeds contain
lysergic acid amide, a compound that is about one-tenth the potency of LSD. After catching two
teenage boys stealing morning glory seeds, a Virginia store changed the bar code on the seeds in
order to monitor the supply and they’re paying closer attention to teenagers who are buying the
seed in large quantities. At this time, little information beyond anecdotal reports is available as
to the extent of this problem.
The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by Maryland Cooperative Extension is implied. Read labels carefully before applying any pesticides. Photographs are by Suzanne Klick, Stanton Gill and Shannon Wadkins unless stated otherwise.

Source: http://www.ipmnet.umd.edu/greenhouse/grnhsandcutalerts/2006/06May12G.pdf