Leaf spot disease caused by Nimbya alternantherae in Alternanthera philoxeroides (Mart.) Grisb.: A new report from India
Anoop K.1* and Abhijnya J.2
1&2Department of Botany, The Zamorin’s Guruvayurappan College, Kozhikode-673014 (India) *email: anoopkuttiyil@gmail.com
ABSTRACT
Alternanthera philoxeroides, commonly known as ‘alligator weed’, is an aquatic perennial herb belongs to the family Amaranthaceae. It is a weed found in temperate and tropical climates of the world. The leaf spot disease in this plant was noted in Kozhikode district of Kerala, India. The infected material was subjected to analysis and the symptoms were noted. The disease was characterized by numerous circular purplereddish colored spots of varying sizes. The spots were found in greyishbrown necrotic centres with purple to red colored borders. Irregular shaped purple spots and streaks were present on internodal region of the stem. Chlorosis was prominent in advanced stages of the disease followed by premature leaf fall. The pathogenicity of the isolate was proved by detached leaf method. Based on the morphological characters, the pathogen was identified as Nimbya alternanthera. This is the first report of this pathogen as leaf spot pathogen of A. philoxeroides in India.