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Indian Journal of Pure & Applied Biosciences (IJPAB)
Year : 2020, Volume : 8, Issue : 2
First page : (95) Last page : (103)
Article doi: : http://dx.doi.org/10.18782/2582-2845.8012

Current Scenario on the Prevalence of Diseases in Economically Important Medicinal and Aromatic Crops of Tamil Nadu

G. Thiribhuvanamala^1* , B. Meena, N. Swarnakumari², I. Geethalakshmi³, P. Muthulakshmi and K. Rajamani^3
1Department of Plant Pathology, ²Deparment of Nematology, ³Department of Medicinal and Aromatic Crops, Tamil Nadu Agricultural University, Coimbatore
*Corresponding Author E-mail: ragumala2000@gmail.com
Received: 19.02.2020  |  Revised: 23.03.2020   |  Accepted: 4.04.2020 

 ABSTRACT

A roving survey for disease assessment was performed in major medicinal plants growing areas of Tamil Nadu during the period from April 2018 to March 2019. The observations  indicated that root rot caused by Macrophomina phaseolina  recorded maximum disease incidence even up to 16.5 to 35 % in Coleus forskohlii at Tiruchengode, Perundurai  and Nambiyur villages.The Macrophomina root rot and Meloidogyme root knot nematode complex was also recorded up to 2 per cent. Recently, the M.phaseolina  has expanded its host range to the medicinal crop Androgrpahis paniculta as recorded at Coimbatore with incidence up to 30%. In Gloriosa superba, severe incidence of root rot  caused by M.phaseolina and tuber rot caused Sclerotium rolfsii  act as a threat to cultivation with incidence ranging from 8 to 23 % and 8.5 to 25 % in Ambilikai, Mulanur, Kallimandhayam , Dharapurum and Nallamaplaaym villages. In these areas, the crop also suffers loss due to leaf blight caused by Alternaria alternata up to 14.6 PDI Recently,symptoms with chlorotic striations in leaves, stunted growth and reduced flower set  with malformed pods were observed due to incidence virus in G.superba . The drought resistant crop Cassia angustifolia also suffers severe yield loss due to Macrophomina root rot and Alternaria leaf blight. Recently, phytoplasmal incidence was now noticed in Solanum trilobatum with incidence up to 9% as in Catharanthus roseus (20 % incidence). The Solanum nigrum also suffers yield loss due to Alternaria leaf blight (11.5 PDI)  and rust incidence (12.5PDI). The aromatic crop Cympopogon martini is also affected by rust caused by Puccinia nakanishiki up to 9.8 PDI. Leaf blight caused by Helminthosporium  sp. is prevalent in Chrysopogon zizanoides and C.martini  with incidence up to 9.5 PDI. Other diseases  of minor medicinal and aromatic crops are also discussed.

Keywords: Medicinal plants, Diseases, Incidence, Root rot, Leaf blight

Full Text : PDF; Journal doi : http://dx.doi.org/10.18782

Cite this article: Thiribhuvanamala, G., Meena, B., Swarnakumari, N., Geethalakshmi, I., Muthulakshmi, P., & Rajamani, K. (2020). Current Scenario on the Prevalence of Diseases in Economically Important Medicinal and Aromatic Crops of Tamil Nadu, Ind. J. Pure App. Biosci. 8(2), 95-103. doi: http://dx.doi.org/10.18782/2582-2845.8012