Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Allelopathic potential of invasive Hypochaeris radicata weed on Brassica napus and Lactuca sativa.

Abstract

We tested whether allelopathic effects of Hypochaeris radicata L. are one in its invasion mechanisms, using Brassica napus and Lactuca sativa as recipient plants. Aqueous extracts of H. radicata did not affect the seed germination but significantly decreased the seedlings root elongation of test species. The H. radicata extract also decreased the growth and chlorophyll content of Brassica campestris ssp. napus var. nippo-oleifera Makina and Lactuca sativa L. seedlings in indoor bioassays, but had no effects in outdoor experiments on B. napus and Erigeron annuus (L.) Pers. This may be due to the climate of Jeju Island i.e. high spring precipitation. Although indoor experiments confirmed the allelopathic effects of H. radicata extracts, but the responses to H. radicata extracts varied in outdoor fields with environmental conditions. As H. radicata is spreading to mainland Korea, where the spring season is usually dry, hence, more studies are needed on the allelopathic effects of H. radicata under dry conditions. As the global climate continues to change, the Pacific area countries will also need to predict H. radicata invasion through careful studies and field monitoring.