In September 1976, the authors collected the leaves of Zizyphus mauritiana Lamk bearing light brown to dark brown spherical as well as irregular spots. These on examination gave Alternaria tenuissima (Kunze ex Pers.) Wiltshire, a pathogen causing leaf spot disease, not reported earlier on this host from India.
The spot were spherical to irregular, not exceeding 0.5 cm square of the leaf on ventral surface. These were light to dark brown. The disease starts as a small pin head sized light brown spot both on the older and younger leaves. Extensions occur with the aging and the spot turns dark brown. The infected regions ultimately become nacrotic. Artificially infected plants developed typical spots of disease in 10-15 days and reinoculation showed the presence of Alternaria tenuissima.
The mycelium is septate, oblivaceous, green to light brown, conidiophores mostly branched, arising singly or in fascicles, brown, varying in length, straight to slightly bent, slightly swollen at the base, 2-5 septate and 28-125X3-4µ in size. Conidia light brown to brown, muriform or obclavate or elliptical with short beaks scarred at the both ends, catenulate, thick walled, about 28-112X8-15µ.
Alternaria tenuissima has been reported on a number of hosts from India but not on Zizyphus mauritiana Lamk; hence Zizyphus mauritiana Lamk is new host record for Alternaria tenuissima for India and the disease has been described as new leaf spot disease reported for the first time in India.
The fungus has been deposited in the herbarium of Commonwealth Mycological Institute, Kew, England as IMI. 210036a and herb. Botany Department, K.S. Saket P.G. College, Faizabad as RSK-271.
Cite this as: Kanaujia R.S. and R. Kishor (1977):A new fungal disease of Zizyphus mairitiana Lamk in India. Fertilizer Technology. 14(3): 286.
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