Floriculture Disorders Eddie McKie Georgia February, 2007
APHIDS Small (up to ¼”) soft- bodied insects. The characteristic feature that distinguishes aphids from other insects are the “tail pipes” (called cornicles) which extend from the rear of their abdomen.
FUNGUS GNATS Adult fungus gnats are about 1/8 to 1/10 inch (2.5 mm) long, grayish to black, slender, mosquito- like, and delicate with long legs, antennae and one pair of wings.
LEAF MINER Insect larvae that feed inside a leaf, between the upper and lower surfaces.
MEALY BUG Mealybugs derive their name from the white, waxy, mealy secretions that cover their bodies.
SCALE Either soft scales or armored scales Covered with waxy shell for most of their life which protects them from predators or insecticides
SLUG Slugs are gastropod mollusks without shells or with very small internal shells, in contrast to snails.gastropod molluskssnails
SPIDER MITE To the naked eye, spider mites look like tiny moving dots Adults have eight legs and an oval body, with two red eyespots near the head end of the body.
POWDERY MILDEW Infected plants will display white powder- like spots on the leaves and stems. The fungus is favored by periods of high relative humidity or site conditions that promote a more humid environment
THRIP Thrips are small (~1/8” long) and narrow-bodied insects commonly found feeding on leaves and stems. The presence of thrips gives a splotchy appearance to leaves.
WHITEFLY Adults are less than 1/8” long and, like their name suggests, have white wings with pale yellow bodies. Adult whiteflies congregate above and under leaf surfaces, and disperse in clouds when disturbed.
BLACKLEG Plants with blackleg are stunted and have a stiff, erect growth habit. Foliage becomes chlorotic and the leaflets tend to roll upward at the margins. Stems of infected plants exhibit an inky black decay. The base of the stem is often completely rotted.black decay In relatively dry soil, only the pith may show blackening.
BLACK SPOT Round to irregular black splotches with fringed margins are quite obvious, mostly on upper leaf surfaces. Round to irregular black splotches with fringed margins are quite obvious, mostly on upper leaf surfaces. Leaf yellowing develops around these black spots, with defoliation of these infected leaves common. Round to irregular black splotches with fringed margins are quite obvious, mostly on upper leaf surfaces. Leaf yellowing develops around these black spots, with defoliation of these infected leaves common. Leaf yellowing develops around these black spots, with defoliation of these infected leaves common.
BOTRYTIS Botrytis is by far the most common fungal disease encountered under cool, humid conditions, particularly were crops are grown at a high density with limited air movement.
DAMPING OFF A common fungal disease that attacks seedlings, weakening the stems right at the soil level. Infected seedlings usually die.
MOSAIC VIRUS Characterized by the presence of intermingled patches of normal and light green or yellowish colored plant tissue.
ODEMA appears as small, sometimes corky blisters which form on the lower surface of leaves or needles. These blisters may eventually harden to form white, tan, or brown wartlike corky bumps on the lower leaf surface.
COLD WATER DAMAGE Often begins with “halo” spots of the leaves caused by overhead watering with cold or cool water.
IRON CHLOROSIS Iron chlorosis is a yellowing of plant leaves caused by iron deficiency that affects many desirable landscape. The primary symptom of iron deficiency is interveinal chlorosis, the development of a yellow leaf with a network of dark green veins.
BERMUDAGRASS Bermudagrass is creeping perennial warm-season grass. Bermudagrass spreads by both rhizomes and stolons. The leaves of bermudagrass are folded in the bud, and the sheath is strongly compressed. The leaf is short, approximately 1/8 inch wide with rough edges. The roots of bermudagrass are deep and fibrous allowing it to be highly drought tolerant. The stolons root at the nodes forming a thick dense mat. The seedhead of Bermudagrass consists of finger-like spikes. Common bermudagrass can spread by seed.
CRABGRASS Crabgras is a low-growing summer annual that spreads by seed and from rootings of nodes that lie on the soil. It may grow upright to a height of 2 feet. It will not tolerate close mowing as well as smooth crabgrass. True leaves are generally 3 inches long and hairy on the upper surface of the leaf and leaf sheath. The branches are l about 2 to 5 inches at the end of the stalk.
NUTGRASS Nutgrass has yellow- green, wide-bladed leaves that are smooth and shiny or waxy on the upper side. Nutgrass grows 1-3 feet tall if not mowed. Yellow and purple varieties
OXALIS The leaves are divided into three to ten or more round, heart-shaped or lanceolate leaflets, arranged in a whorl with all the leaflets of roughly equal size. The majority of species have three leaflets; in these species, the leaves are superficially similar to those of some clovers