Herbicidal effects of mixture of oxygenic terpenoids on paddy weeds

To further explore the practical application of allelochemicals in rice production, the mixture of five oxygenic terpenoids [(') carveol, (+) carvone, (') menthone, (') carvyl acetate, and (+) cedrol] identified in previous study, was evaluated in green house for their herbicidal activity on paddy weeds. This terpenoid mixture effectively reduced the growth (aboveground dry weight) of most paddy weeds by 90.0% in 2007 and 83.3% in 2009, respectively, over control. However, the growth of two tested hybrid rice cultivars (Shan-You 63 and Te-You-Hang II) was enhanced after the terpenoid mixture treatment. This study suggested that allelochemicals (including terpenoids), could be used as novel component of integrated weed management in rice production.