Abstract: Background: Parthenium hysterophorus L. is one of the top ten worst weeds globally and is recorded in the global database of invasive species. Objective: The current study was aimed to evaluate the herbicidal potential of Alternaria brassicicola (Schwein.) Wiltshire and Alternaria gaisen Nagano. culture filtrates against a problematic weed P. hysterophorus. Methods: A. brassicicola and A. gaisen culture filtrates were tested in vitro against the test weed. A. gaisen culture filtrates were found most effective against the test weed, and this test fungus was partitioned with various fractions viz. n-hexane, chloroform, ethyl acetate and n-butanol were isolated. In vitro bioactivity of these fractions were tested against P. hysterophorus. The most productive n-hexane fraction was subjected to GC-MS analysis, and thirteen compounds were identified. Results: A. gaisen original (100%) and diluted (50%) culture filtrates showed significant herbicidal activity against P. hysterophorus. However, culture filtrates of A. gaisen suppressed the germination, root and shoot growth of the test weed to a greater extent compared with culture filtrates of A. brassicicola . Original culture filtrates of A. gaisen significantly reduced germination of P. hysterophorus by 88% as compared to diluted concentration by 56% in comparison with control. On the other hand, original and diluted culture filtrates of A. brassicicola reduced the germination of P. hysterophorus by 69% and 50%, respectively, over control treatment. The n-hexane fraction was found more effective in suppressing the P. hysterophorus growth as compared to other fractions. Both 0.10% and 0.05% concentrations of n-hexane fraction significantly inhibited P. hysterophorus seedlings germination by 88% and 81%, respectively. The n-hexane fraction was subjected to GC-MS analysis, and thirteen compounds were identified. Among these, ocimene (27.63%); benzene 1-ethyl-3-methyl-(20.30%) and n-hexadecanoic acid (10.27%) were major compounds. Conclusion: The present study concludes that A. gaisen culture filtrate has substantial herbicidal potential against P. hysterophorous.

Abstract The current study was designed to evaluate the antifungal properties of Datura metel L. against Rizoctonia solani Kuhn. To achieve this objective, six concentrations of leaves & stem methanol extract of D. metel viz. 1%, 1.5%, 2%, 2.5%, 3% & 3.5% were tested against R. solani in vitro. Leaf extract of D. metel was found more effective as its 3.5% concentration caused 75% retardation in test fungal growth as compared to the stem extract. D. metel methanolic leaf extract was fractioned between n-butanol, n-hexane, chloroform & ethyl acetate & bioactivities of isolated fractions were tested against R. solani. The chloroform fraction was found highly effective, as its concentrations 0.1% & 0.01% caused 27% & 21% growth inhibition respectively. So, this particular chloroform fraction was further analyzed to identify various chemical constituents through GC-MS (Gas chromatography mass spectroscopic) analysis. Twelve phyto-constituents viz. eugenol, 2-pentadecanone 6,10,14 trimethyl, pentadecanoic acid, pentadecanoic acid, 1 4-methyl- methyl ester, phytol, 9,12,15-octadecatrienoic acid, heptacosane, n-hexadecanoic, 6-octadecanoic acid, 9, 12 octadecanoic acid, dodecanoic & tetradecanoic acids were identified. So, the present study concluded that the presence of these bioactive constituents make D. metel as an effective antifungal agent against R. solani.