Effect of Soil Type and Seasonal Variation on Growth, Yield, Essential Oil and Artemisinin Content of Artemisia Annua L

Abstract

Aims: This experiment was carried out to study the effects of soil type and seasonal variation on growth, yield, essential oil and artemisinin content of Artemisia annua plant. Methods: Two field experiments were carried out during two successive seasons in two different types of soil, loamy clay soil and sandy loam soil. Artemisia seeds were cultivated in nursery plots at 15th December then transplanted at age of 90 days in a distance of 60cm in apart and 50cm in between plants under organic system then plant samples were collected every 30 days through growth season. Results: Significant increases in vegetative growth characters were observed for plants cultivated in clay loamy soil comparing to those cultivated in sand loamy soil. The plant essential oil percentage of those cultivated in sand loamy soil were increase more than those cultivated in clay loamy soil while essential oil yield of plants grown in clay loamy soil was more than those grown in sand loamy soil. Essential oil % of A. annua aerial parts in the two soils increased with increasing plant age to reach its maximum values at full flowering stage then this tended to decrease towards the end of plant life. The major compound in the essential oil was found to be artemisia ketone followed by 1,8 cineole in both soils. A change in the order of the followed compounds according to the soil type was observed. Artemisinin % and artemisinin yield (kg/fed) of plants cultivated in sand loamy soil was increased in comparing to plants cultivated in clay soil and showed the maximum values of artemisinin % at the flowering stage in August in both types of soil. Conclusion: Cultivation of A. annua in sandy loam soil resulted in increasing essential oil percentage whereas clay loam soil increased oil yield as it increased all vegetative parameters. Artemisia ketone and 1,8 cineole are major compounds in essential oil and their percentage in essential oil for sandy loam soil plants were more than of clay loam plants.