~ 675 ~ The Pharma Innovation Journal 2021; 10(4): 675-679 ISSN (E): 2277- 7695 ISSN (P): 2349-8242 NAAS Rating: 5.23 TPI 2021; 10(4): 675-679 © 2021 TPI www.thepharmajournal.com Received: 18-02-2021 Accepted: 20-03-2021 Akhilesh Patel Ex-M.Sc. Student, Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology & Sciences, Prayagraj (Allahabad), Uttar Pradesh, India Mohd. Danish Ph.D. Scholar, Department of Entomology, Sam Higginbottom University of Agriculture, Technology & Sciences, Prayagraj (Allahabad), Uttar Pradesh, India Mukesh Kumar Prajapati Ph.D. Scholar, Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology & Sciences, Prayagraj (Allahabad), Uttar Pradesh, India Anoop Kumar Ph.D. Scholar, Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology & Sciences, Prayagraj (Allahabad), Uttar Pradesh, India Abhilasha A Lal Assistant Professor, Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology & Sciences, Prayagraj (Allahabad), Uttar Pradesh, India Corresponding Author: Akhilesh Patel Ex-M.Sc. Student, Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology & Sciences, Prayagraj (Allahabad), Uttar Pradesh, India In vitro efficacy of plant extracts against Alternaria lini (leaf blight of linseed) Akhilesh Patel, Mohd. Danish, Mukesh Kumar Prajapati, Anoop Kumar and Abhilasha A Lal Abstract This research work deals with the study of “In vitro efficacy of plant extracts against Alternaria lini (leaf blight of linseed)”. It is the second most important rabi oilseed crop and stands next to rapeseed-mustard in area of cultivation and seed production in India. Alternaria lini is a highly destructine pathogen. The disease caused by this fungus is characterized by leaf spot appearance on the plant leaves Small circular dark brown lesion with paler margin and yellow halo, usually circular in shape, first small and then enlarged to 2 to 3 cms in diameter. Leaf blight is one of the most economically important diseases world- wide. It affects every part of infected plant. Regular use of fungicide will be hazardous for the soil and humans as well. The lab experiment was analysed using C.R.D. (Complete Randomized Design) with three replications and eight treatments including six botanicals. Treatments like control (Untreated), Jatropha (5%, 8% and 12%), Tulsi (5%, 8% and 12%), Neem (5%, 8% and 12%), Neem (5%, 8% and 12%), Bougainvillea (5%, 8% and 12%), Gulmohar (5%, 8% and 12%) and Parthenium (5%, 8% and 12%)Observations were recorded at different time intervals at 72 and 96hrs for the mycelium growth of the pathogen and inhibition per cent. Jatrophaleaf extract @12%recorded lowest radial growth and highest radial inhibition (%) against Alternaria lini causing leaf blight of linseed (Linum usitatissimum L.). The results of present experiment are under Allahabad conditions as such more trials should be carried out in future to validate the findings. Keywords: Alternaria lini, botanicals, management Introduction Linseed or flax (Linum usitatissimum L., 2n= 30, X = 15) belongs to the order Malpighiales, the family Linaceae, and the tribe Lineae. Linseed is an important rabi oil seed crop and a major source of oil and fibre. The average productivity of this crop is very low (about 3.0 q/ha), for which diseases are one of the major reasons. Among fungal diseases, Alternaria leaf /bud blight caused by A. lini Dey is a serious threat in Northern high humidity regions of the country causing 58.44% yield losses (Singh et al., 2014) [16] . Linseed is one of the most important crops of the world cultivated in over 2.6 million ha. The important linseed growing countries are India, Canada, China, USA and Ethiopia. India ranks first in the world in respect of acreage accounting for 23.8% of the world total and third in production contributing of 10.2% of the world total. Canada and China are other main linseed producers in the world. The productivity is the highest in Romania (1751.4 kg/ha). It is cultivated in the world over an area of 22.70 lakh ha with a production of 22.39 lakh t and productivity of 986 kg/ha. In India, it occupies an area of 3.38 lakh ha with a production of 1.47 lakh t and a productivity of 435 kg/ha (FAO, 2013) [5] . The major part of linseed growing area lies in the states of Madhya Pradesh, Himachal Pradesh, Chhattisgarh, Uttar Pradesh, Maharashtra, Bihar, Odisha, Jharkhand, Karnataka and Assam accounting for more than 97 per cent of the total area. (Anonymous, 2014) [2] . India area of linseed in India 0.31 lakh hactare and production of linseed1.55mitric ton and its productivity rate is 1285 q/hac in 2016-2017 and the major linseed producing states in India are: West Bengal, Bihar, Madhya Pradesh, Rajasthan, Gujarat, Maharashtra, Orissa, and Uttar Pradesh. The area, production and productivity of linseed in Uttar Pradesh were 0.23 mha, 60.48 MT, 0.12 Mt/ha and 4.78 q/ha, respectively (National Horticulture Board, 2016-2017) [12] . Disease was first reported by Dey (1933) from Kanpur in Uttar Pradesh. The disease was found to cause heavy damage, especially in low lying, ill-drained fields with the yield losses ranging from 28-60 per cent. (Chauhan and Srivastava 1975) [4] .