Studies on Coloured Leaf Spot Disease of Alchornea caused by Taphrina Derformans
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Asian Network for Scientific Information
he coloured leaf spot disease of Alchornea cordifolia leaves was investigated and the fungal causal agent was isolated on yeast malt extract agar. The epidemiology of the disease on the university of Lagos, Akoka campus was also studied. Taphrina deformans was isolated from the diseased leaves of Alchornea cordifolia. The coloured leaf spot disease is characterised by an initial appearance of pink spots on the leaves, as the disease progresses, an intermediate stage occurs which is brownish-red in colour and eventually turned brown at the old stage. The disease epidemic is rampant between June and November of the year. The average leaf area of the pink spot was 1.61±0.22 cm2 and brown spot was 1.74±0.13 cm2. The mean leaf area of the healthy leaf is 8.64±0.15 cm2. Free hand sections of the diseased leaves revealed the presence of T. deformans ascus on the epidermal layer of A. cordifolia leaf, rupturing the epidemis to reveal the ascus, as well as disjointed intercellular presence of the fungal hyphae. The chlorophyll content of the healthy leaves of A. cordifolia was 0.24±0.059 μg g-1, while the diseased leaves had 0.22±0.099, 0.22±0.065 and 0.16±0.070 μg g-1 chlorophyll content for the pink, brown-red and brown spot stages. T. deformans grew best on A. cordifolia leaf extract broth than on potato dextrose broth and yeast malt extract broth.
Leaf Spot , Epidermology , Chlorophyll
Adekunle, A.A, Uma, N.U and Oleah, A.M (2005) Studies on Coloured Leaf Spot Disease of Alchornea cordifolia Caused by Taphrina deformans. Plant Pathology Journal 4(2)