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Updated: May 23, 2026
Repeatable Stair-step Assay to Access the Allelopathic Potential of Weedy Rice (Oryza sativa ssp.)
Published on: January 28, 2020
Concentrations and allelopathic effects of benzoxazinoid compounds in soil treated with rye (Secale cereale) cover
Clifford P Rice1, Guimei Cai, John R Teasdale
1Animal and Natural Resources Institute, Agricultural Research Service, U. S. Department of Agriculture, 10300 Baltimore Avenue, Beltsville, Maryland 20705, United States. Clifford.rice@ars.usda.gov
Abstract:
The concentration of benzoxazinoids (BX) was measured in field soils at selected intervals after rye residue was either incorporated or left on the soil surface. The spectrum of compounds arising in the soil persisted approximately two weeks and was dominated by methoxy containing BX compounds, which were only minor components of the rye foliage. Growth assays with lettuce and smooth pigweed species showed inhibition when treated soils were tested during the first two weeks after rye applications; however, there were no sufficient concentrations of any one BX compound in the soil to explain these affects. Solution applications of two pure BX compounds, benzoxazolin-2(3H)-one (BOA) and 6-methoxy-benzoxazolin-2(3H)-one (MBOA), to the surface of soils revealed that movement into the soil column was minimal (greater than 70% BOA and 97% MBOA remained in the top 1-cm of soil profiles) and that the time course for their complete dissipation was less than 24 h.
