By M. Moghaddam, R. Omidbiagi and F. Sefidkon

Abstract: Abstract: The essential oil content and chemical composition of Tagetes minuta L. was determined at different harvesting times of budding, full flowering and fruit set stages. The oil was obtained by hydrodistillation of all samples, and was analyzed by GC and GC/MS. The oil content of samples which were harvested at budding, full flowering and fruit set stages were 1.55%, 1.44% and 1.0% (w/w) on a dry weight basis, respectively. Nineteen, 20 and 19 compounds have been identified in the oils of budding, full flowering and fruit set stages of T. minuta, respectively. The major compounds were limonene, dihydrotagetone, (Z)-tagetone, (E)-ocimenone and α-terpineol. The results showed that harvest times had a major effect on the constituents of the oil of T. minuta. Key Word Index: Tagetes minuta, Asteraceae, harvest time, essential oil composition, dihydrotagetone, (Z)-β-ocimene, (Z)-tagetone, α-terpineol.

Introduction
The genus Tagetes (Asteraceae) contains 56 species and includes annual and perennial species. Tagetes species are mainly cultivated for ornamental purposes all over the world. The genus is also known for its essential oil present in leaves and flowers which make it an important crop (1).

Tagetes minuta L. is an annual, herbaceous essential oil plant. It is native to southern South America. This plant is wild growing and also cultivated at different parts of the world such as South African, Australian, Nigeria, New Zealand, Russia, India, Uruguay, East African, Brazil, France, Chile, Bolivia and the Chaco region of Paraguay (2–4). It is used as a condiment and for medicinal purposes. Its essential oil exhibits hypotensive, spasmolytic, anti-inflammatory, anti-microbial and anti-fungal properties (3,5). Tagetes minuta oil finds a good market as an ingredient in the perfumery and flavor industries. The oil has been reported to show 100% inhibitory effect on Gram + bacteria, 95% inhibitory effect on Gram - bacteria and 100% inhibitory effect on fungi (6). Also (E)-ocimenone [(E)-tagetenone] at a concentration of 40 ppm as found to cause 100% mortality of mosquito (Aedes aegypti) larvae (7).

Numerous reports have appeared on chemical composition of the oil of T. minuta at different growth stages (3,8,9). The aim of this investigation is examined the oil content and composition of T. minuta at different harvest stages.