Application of Chenopodium ambrosioides Linn. essential oil as botanical fungicide for the management of fungal deterioration in pulses.

Essential oils isolated from 35 aromatic plants of Gorakhpur Division, India, were screened at 0.36 μl ml^-1 against four dominant fungi Aspergillus flavus Link, A. niger van Tieghem, A. ochraceus Wilhelm and A. terreus Thom found on stored pigeon pea (Cajanus cajan Linn.) seeds. Chenopodium ambrosioides Linn. and Citrus aurantium Linn. oils exhibited strong antimycotic activity (100% mycelial inhibition). The minimum inhibitory concentration of C. ambrosioides oil was less (0.07 μl ml^-1) than that of C. aurantium oil, against all the test fungi. Both the oils were fungicidal at higher doses (1.71-2.78 μl ml^-1). C. ambrosioides oil exhibited broad fungitoxic spectrum against 16 other storage fungi of pigeon pea seeds. The oil remained effective with increased inoculum load, and physical factors had no adverse effect on its toxicity. C. ambrosioides oil proved superior to aluminium phosphide and ethylene dibromide, synthetic fumigants, at 0.29 μl ml^-1 and significantly protected 1 kg of pigeon pea seeds from microbial attack for up to 6 months. Chenopodium oil can be recommended as an effective substitute of synthetic fumigants for storage of pigeon pea seeds. [ABSTRACT FROM AUTHOR]