Inhibitory effects of woodchips on growth of climbing bean plant Kudzu vine (Pueraria lobata Ohwi)

In pot culture, we studied the allelopathic weed control potential of water extracts of wood chips of 4 trees viz., Japanese cedar (Cryptomeria japonica (Thunb. ex L.f.) D. Don), gland-bearing oak (Quercus serrata Thun.), Manchurian walnut (Juglans mandshurica, Maxim.), and Japanese red pine (Pinus densiflora Siebold & Zuccarini) on kudzu vine (Pueraria lobata Ohwi). Periodical exposure of kudzu shoots to the extracts of sapwood chips of Japanese cedar, gland-bearing oak significantly inhibited the kudzu vine shoot growth, whereas, those from the sapwood chips of Manchurian walnut and Japanese red pine had no effects on kudzu growth. The water extracts of the sapwood chips of cedar and oak contained phenolic and carboxylic acids as the allelochemicals that might have caused the growth inhibition of kudzu.