Induction and inhibition of Striga hermonthica (Del.) Benth. germination by extracts of traditional Chinese medicinal herbs

• Published in: Agronomy journal Vol. 96; no. 5; pp. 1349 - 1356
• Main Authors: Ma, Y.Q, Cheng, J.M, Inanaga, S, Shui, J.F
• Format: Journal Article
• Language: English
• Published: Madison, WI American Society of Agronomy 01.09.2004
• Subjects: Agronomy. Soil science and plant productions; bioherbicides; Biological and medical sciences; biological control; Chinese medicinal plants; Fundamental and applied biological sciences. Psychology; herbicides; medicinal plants; plant extracts; seed germination; Striga hermonthica; weed control; Chinese; Inhibition; Agronomy; Germination; Medicinal plant
• ISSN: 0002-1962; 1435-0645
• DOI: 10.2134/agronj2004.1349

Striga hermonthica (Del.) Benth. is a root parasitic weed that reduces the yield of many important cereals in the semiarid tropics in Africa. Yield losses from damage by the parasite are often significant, and complete crop failure is not uncommon. The prolonged use of nonhost plants that produce S. hermonthica germination stimulants may reduce seed reserves in soil over time. The production of high-value medicinal herbs with S. hermonthica germination induction properties in soils infested with S. hermonthica seed would offer growers an alternative crop as well as potentially reducing S. hermonthica seed reserves. We screened the extracts of 383 traditional Chinese medicinal herbs to test their ability to induce or inhibit the germination of S. hermonthica seeds. Distilled water and methanolic extracts of over 20 herbs induced S. hermonthica germination. Herb extracts that induced S. hermonthica germination rates greater than 50% were Acorus gramineus Soland., Agrimonia pilosa Ledeb. var. japonica (Miq.) Nakai, Areca catechu L., Citrus tangerina Hort. et Tanaka, Cudrania cochinchinensis (Lour.) Kudo et Masam., Nardostachys chinensis Batal., Oldenlandia diffusa (Wild.) Roxb., Portulaca oleracea L., Scrophularia ningpoensis Hemsl., and Semiaquilegia adoxoides (DC.) Mak. Water extracts from 27 herbs inhibited S. hermonthica germination. The undiluted extract from Curcuma longa L. completely inhibited S. hermonthica germination. Undiluted extracts from 15 other herbs reduced germination by more than 50% compared with the positive control. The results from this study indicate that metabolites produced by some traditional medicinal herbs may have the potential to be used as bioherbicides to control S. hermonthica.