Black sooty mold l&c

black sooty mold

1. Presenters: Joel Manning and Marcus Shepherd Date: October 11,2019 BLACK SOOTY-MOLD

2. INTRODUCTION

3. BLACK SOOTY-MOLD The black residue of sooty mold is composed of dark fungal threads of a number of ascomycetes . These fungi grow in flowing sap or on honeydew excreted by aphids and other sucking insects. Although the condition is unsightly, it usually is not harmful. Control includes spraying or dusting for sucking insects, washing off sticky coatings of sap or honeydew on plant surfaces, and avoiding the wounding of plants.

4. Sooty mold Appears as a black staining or powdery coating on leaves and stems. While the black leaves may become unsightly, sooty-mold itself does not directly harm the plant. Instead the black fungus affects the plant indirectly by shading the leaves which interferes with photosynthesis, potentially slowing plant growth and reducing the long-term vigor of the plant.

5. Where does it come from ? Sooty mold grows on a substance called “honeydew” which is excreted from certain insects such as aphids, soft scales, whiteflies and mealy bugs. These insects feed on a variety of landscape plants and can be found on the leaves and stems where they use special mouthparts to pierce plant tissues and suck out the juices from within. During this time these insects excrete large amounts of a sticky, sugary Substance commonly called “honeydew”. The excreted honeydew coats leaves, stems, and fruit, Stimulating the growth of sooty-mold.

6. Honeydew Producing Insects Figure 1: Mealy bugs Figure 2: Hemispherical scale on coontie .

7. Con’t Figure 3: Florida wax scales along leaf veins . Figure 4: Whitefly adult (left) resembling a moth and immature nymphs (right) which resemble scale insects.

8. How do you get rid of the black mold? Before you run out to purchase a fungicide to rid your plant of the black sooty mold, there is something you should know. The black mold will only go away once the insect pest is controlled. To rid your plants of these insects, you can spray them with an insecticidal soap or lightweight horticultural oil such as neem oil. Be sure to spray all parts of the plant, including the undersides of the leaves, and follow the label directions, repeating the treatment as directed on the label or at weekly intervals as necessary.

9. REFERENCES French , Bruce R. (1982). Growing food in the Southern Highlands Province of Papua New Guinea (PDF). AFTSEMU (Agricultural Field Trials, Surveys, Evaluation and Monitoring Unit) of the World Bank funded project in the Southern Highlands of Papua New Guinea. pp. 64–71. Retrieved 20 September 2018. Aisnworth GC (1981). Introduction to the History of Plant Pathology. Cambridge University Press. ISBN 978-0-521-23032-2.

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