INTERNATIONAL JOURNAL OF AGRICULTURE & BIOLOGY ISSN Print: 1560–8530; ISSN Online: 1814–9596 16–627/201x/00–0–000–000 DOI: 10.17957/IJAB/15.0278 http://www.fspublishers.org Full Length Article To cite this paper: Ishaq, M., R. Tahira, A. Jamal, A. Javed, M.U. Raja and A. Munir, 201x. Lemongrass essential oil as an alternate approach to manage seed associated fungi of wheat and rice. Int. J. Agric. Biol., 00: 000-000 Lemongrass Essential Oil as an Alternate Approach to manage Seed Associated Fungi of Wheat and Rice Muhammad Ishaq 1 , Riffat Tahira 2*† , Atif Jamal 3 , Asif Javed 1 , Muhammad Usman Raja 4 and Anjum Munir 3 1 Department of Earth & Environmental Sciences, Bahria University, E-8, Islamabad, Pakistan 2 Plant Genetic Resources Institute, NARC, Park Road, Islamabad, Pakistan 3 Crop Diseases Research Institute, NARC, Park Road, Islamabad, Pakistan 4 Department of Plant Pathology, PirMehr Ali Shah University, Rawalpindi, Pakistan † Present Address: Social Sciences Research Institute (PARC), AARI, Jhang Road, Faisalabad. * For correspondence: rt_bashirch@hotmail.com; tahirariffat30@yahoo.com Abstract Rice and wheat germplasm were vetted for the presence of seed both saprophytic as well as pathogenic fungi associated with wheat and rice seeds. Seven fungal species viz., Alternaria alternata, Aspergillus flavus, Aspergillus niger, Curvularia lunata, Drechslera indica, Drechslera tripogonis and Fusarium moniliforme were associated with rice while five fungi viz., Alternaria alternata, Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger and Drechslera indica were found in wheat. Among all the isolated fungi, Aspergillus flavus was found as predominant funus (41%) associated with seeds of rice and (33%) with wheat seeds. The antifungal potential at different concentrations of lemongrass essential oil was tested by using disk diffusion method against isolated fungal species. Minimum inhibitory concentration (MIC) of lemongrass essential oil against each fungus was determined through agar plug method. Highest MIC (55 ppm) was recorded for Aspergillus flavus and lowest for Drechslera indica (20 ppm). Significant differences were recorded for different concentrations of lemongrass essential oil against isolated fungi (p≤0.05) against tested fungi. However, Aspergillus niger was found to be the most susceptible fungal strain to lemongrass essential oil. Results of the contemporary experiments indicate that lemongrass essential oil could be employed as alternate to synthetic fungicides during grain storage. © 2017 Friends Science Publishers Keywords: Lemongrass essential oil; Seed associated fungi; Rice; Wheat; Aspergillus niger Introduction Rice (Oryza sativa) and wheat (Triticum aestivum) are the main food of Pakistani population. These plants are subjected to environmental stresses and numerous injuries at all stages of growth that interfere with their normal functioning and development. Each year about 20% of the wheat would be available for food otherwise lost due to diseases (Fakir, 1999). Seed health plays a vital role in the successful cultivation and exploration of yield of crop species. Among various factors that affect the health of seed, the most important are the seed associated fungal pathogens that not only lower the seed germination but also reduces seed vigor resulting in low yield (Huynh et al., 2001). Fungal pathogens are economically most important as they affect seed quality. It is challenging to control fungal seed-borne diseases, as fungal hyphae get established into seed and become dormant. Seed robustness is reduced which results in retarded plant growth at initial stages. Loose smut (Ustilago tritici), bakanae disease of rice (Fusarium moniliforme), flag smut (Urocystis tritici), karnal bunt (Nevossia indica) and ear cockle of wheat (Anguina tritici) are seed borne diseases (Javaid and Anjum, 2006). Untreated seeds grown in the field are not only responsible for causing variation in plant morphology but also reduction in crop yield up to 15-90% (Wise, 1984). To increase wheat and rice yield, it is obligatory to espouse and practice cheap, eco-friendly and environmentally safe control methods to lessen the incidence of seed borne pathogens. Excessive and persistent application of synthetic antifungal agents exerts adverse effects on environment and may lead to resistance of pathogens against these agents. Varma and Dubey (1999) suggested plant based pest controlling chemicals as better choice to reduce or eliminate the fungal infection associated with seeds as they have minimal impact on environment as compared with synthetic pesticides. Lemongrass (Cymbopogon citratus) is an aromatic tall herbaceous plant belonging to genus Cymbopogan of family Poaceae (Akhila, 2010). Lemongrass essential oil possesses biologically active constituents including citral contents