Web blight of East India holly fern caused by Rhizoctonia solani
2002
Wood, Tillman F IV | McMillan, Robert T. Jr | Graves, William R.
In December 1999, in a south Florida commercial nursery, 10% of the Arachniodes simplicor "variegata" (Mak.) Ohwi ferns in containers showed necrotic areas on the fronds. Rhizoctonia solani Kuehn was isolated from the ferns on corn meal agar. Five 3 x 3 mm pieces of uninoculated potato-dextrose agar were placed on eight control plants sprayed with tap water. The plants were then placed in plastic bags and allowed to incubate for two days at room temperature. Eight treated plants were sprayed with tap water. These plants were then inoculated with five 3 x 3 mm pieces of potato-dextrose agar from a 3-day-old R. solani culture and placed in the plastic bags and allowed to incubate at room temperature (25 °C) for two days. The bags were removed and plants were placed in a greenhouse (20 °C night/28 °C day) and observed for signs of infection. Infection appeared as necrotic areas around the oculum within two days. The infection progressed along the frond as a spreading light brown necrosis that eventually encompassed most of the frond. The fronds changed color from their normal dark green with yellow to light green center variegation and then to brown within one month. The fungus consistently reisolated from the plants was R. solani.
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