Allelopathy Journal

  • Year: 2006
  • Volume: 18
  • Issue: 2

Assessment of allelopathic potential of aqueous extracts of Praxelis (Praxelis clematidea) under laboratory conditions.

  • Author:
  • Z.H. Wang, P. Christie, Q.B. Chen, G.Y. Lan, F. An, X.L. Li
  • Total Page Count: 1
  • DOI:
  • Page Number: 11 to 11

Department of Plant Nutrition, China Agricutural University, Beijing-100094, China; Rubber Cultivation Research Institute, Ministry of Agriculture Key Laboratory for Tropical Crop Physiology, CATAS, Danzhou-571737, Hainan, China; Agricultural and Environmental Science Department, Queen's University Belfast, Newforge Lane, Befast BT9 5PX, UK

Abstract

Allelopathic effects of aqueous extracts of fresh Praxelis (Praxelis clematidea) material were determined on germination While influence of extracts from fresh and dry Praxelis material and soil were studied on initial seedling growth in four crops: Chinese cabbage (Brassica campestris L. ssp. Pekinensis (Lour.) Olsson), radish (Raphanus sativus L.), rice (Oryza sativa L.) and Stylosanthes CIAT184 (Stylosanthes guianensis cv. Reyan No.2). All fresh Praxlis aqueous extracts inhibited seed germination in all four test species. Leaf, flower and whole plant extracts exhibited greater phytotxicity than other plant parts. The allelochemicals may be released mainly by leaves and flowers. Praxelis extracts severely inhibited the root growth of the crops with a similar trend with extracts of fresh material at lower concentrations. Soil extracts had little adverse effect on the test species and actually showed stimulatory effects on some parameters in some plant species. Allelopathic effects of extracts from immature and flowering Praxelis showed no effects on radish. Allelopathic activity of P. clematidea increased under adverse (arid) conditions under which more allelochemicals may have been released.