Blossom blight can also be a serious problem during shipment of potted plants and cut flowers, such as carnations, chrysanthemums, geraniums, and snapdragons, with bud blight causing problems during cold storage of plants like hydrangeas.ģ - 3 - Stem Canker, Stem and Crown Rot, Wilt, and Cutting Rot Black or caramel-colored, sunken and elongated lesions, with a definite outline, frequently appear on succulent stems or stalks of such ornamentals as begonia, geranium, exacum, peony, rose, and snapdragon. Blight or blast is very common on leaf and flower buds of peony and rose, causing them to turn brown or black. Flowers can also become infected while still in the bud. Hydathode infections of leaf margin on right (Nat. Figure 7 - lesions from infected petals on healthy leaves. Figure 6 - cut stub in foreground spore production (gray mold) on stem. Spore production of the fungus 3, florets have matted 4, rot progressed into pedicel, flower collapsed (5) bud blast of peony (6) stem rot of geranium, and (7) leaf blight of geranium. Botrytis blight of (2) chrysanthemum blooms, (3) geranium, and (4) cyclamen. The fungus may invade the pedicel, which rots and leads to bud and flower collapse (Figure 4) Figures 2-7. The petals of badly infected flowers often become matted and stick together. The mycelium of Botrytis may continue to grow and invade the rest of the inflorescence, and, if moist conditions persist, spore production can occur (Figure 3). Infected petals wither and turn tannish brown (Figure 2). Flowers are particularly susceptible as they begin to age. The fungus becomes established in flower petals and sometimes appears as irregular, enlarged, tannish, water-soaked flecks or spots (Figure 1). ![]() University of Illinois Extension provides equal opportunities in programs and employment.Ģ Blossom or Flower Blights and Bud Rots Blossom blight and bud blight of such ornamentals as asters, azalea, begonia, carnation, chrysanthemum, cyclamen, dahlia, geranium, marigold, peony, petunia, roses, and snapdragon very often precede and lead to stem rot. Pataky, Extension Specialist and Director of the Plant Disease Clinic, Department of Crop Sciences, University of Illinois at Urbana-Champaign. For further information concerning diseases of ornamentals, contact Nancy R. Flag to roundish, black resting bodies (sclerotia) of the fungus can appear on infected and sporulating tissue as the plant or plant part dies. ![]() A conspicuous, tan to gray fuzzy mold (composed of many thousands of spores borne in grapelike clusters) develops on rotted tissue under humid conditions. Botrytis infection first appears as a water-soaking and browning regardless of the tissue affected. Symptoms Botrytis cinerea causes blossom blight, bud rot, stem canker, stem and crown rot, cutting rot, leaf blight, and damping-off or seedling blight. It should be remembered that most ornamental plants, even if not officially recorded as hosts, are probably susceptible to one or more species of Botrytis under the right circumstances. Table 1 is a partial list of some of the ornamental plants affected by Botrytis cinerea. Botrytis cinerea has by far the largest host range of any species of Botrytis, and the following discussion will deal almost entirely with Botrytis blight of ornamentals caused by cinerea. ![]() There are some 50 species of Botrytis, accounting in part for the wide range of plants and plant parts affected. Blight is the most common symptom, however, fruit, vegetable, tuber, stem, corm, and bulb rot and leaf spot or blotch are also symptoms of Botrytis infection. Actively growing tissues, other than flower petals, are seldom invaded. With some exceptions, however, Botrytis blight mainly attacks tender tissues (flower petals, buds, or seedlings), weakened or injured tissues (such as stubs or bases left on stock plants after cuttings), and aging and dead tissues. Botrytis petal blight of petunia showing lesions or spots (Dr. The causal fungus can invade and damage many plant parts including flowers, pedicels, stems, leaves, buds, Figure 1. It also causes damage on many fruits and vegetables and can be a serious problem during both short- and long-term cold storage and subsequent shipment of most types of horticultural commodities. ![]() Botrytis blight frequently occurs on the same hosts in out-of-door plantings, especially during or following cool, damp, cloudy weather. 623 August 1997 DEPARTMENT OF CROP SCIENCES UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN BOTRYTIS BLIGHT OR GRAY MOLD OF ORNAMENTAL PLANTS Botrytis blight or gray mold, one of the most common and destructive diseases of greenhouse-grown crops, is estimated to cause a greater economic loss of ornamentals and vegetables than any other disease.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |