Allelopathic Potentials of Cuscuta campestris Yuncker Extracts on Germination and Growth of Radish (Raphanus sativus L.) and Lettuce (Lactuca sativa L.)

Cuscuta campestris Yuncker, commonly known as Golden dodder is an annual problematic parasitic weed in abandoned and derelict areas in Malaysia. The weed is leafless plant, glabrous, yellow-white in colour, with haustoria, sucker-like attachments to the aerial parts of a wide range of host plants. This study was instituted to assess the allelopathic potentials of C. campestris on lettuce and radish as test plants. Three types of treatment using aqueous extract of fresh (fc), and dried s (dc) and ethanol extract of dried C. campestris (ec) were assayed for their allelopathic effects on radish (Raphanus sativus) and lettuce (Lactuca sativa) seeds. These extracts reduced seed germination, root and shoot lengths of both radish and lettuce. The roots of radish were more sensitive vis-à -vis the shoots when exposed to fc, while shoots were more sensitive than roots when exposed to dc. Dose-mediated differences in shoot and root lengths of radish were registered when treated with ec. The roots of lettuce were more sensitive compared with the shoots when exposed to ec, while no measurable effect was observed when roots and shoots of lettuce were exposed to fc and dc. The results demonstrated the allelopathic effects of dodder on the tested host plants. The potentials of these extracts and their chemical constituents as bioactive ingredients for new herbicides are implied.