Mimosine in Leucaena as a potent bio-herbicide

Abstract - Mimosine [-amino--(3-hydroxy-4-oxo-1,4-dihydropyridin-1-yl)-propanoic acid] is a major constituent of Leucaena (Leucaena leucocephala de Wit) and responsible for the strong allelopathic potential of the legume tree. Mimosine showed strong herbicidal activities on six plants in a bioassay. All plant parts of Leucaena contain mimosine. The quantity of mimosine in the young leaves and mature seeds was the greatest, 2.66 and 2.38% of dry weight, respectively, while the quantity in the root xylems and xylems was the lowest: 0.18 and 0.11% of dry weight, respectively. Younger plant parts of Leucaena contained greater amounts of mimosine than the mature parts. Mimosine released from young parts and the seeds of Leucaena was proportional to the quantity of soaking water. Compared with the mature seeds, other mature parts of the plant did not give any mimosine through exuding. In soil to which mimosine was added, about 60% of the mimosine was adsorbed in 1-5 days, and only a minor volume of mimosine was decomposed: 5.30 and 0.16% after 1 and 5 days, respectively. Using a mixture of FeCl₃ and mimosine in a 4:6 ratio may be the most effective and economical method of lowering the toxicity of mimosine in Leucaena leaves, giving a safer cattle feed and decreasing the soil toxicity caused by mimosine in areas where Leucaena is grown. On the other hand, the incorporation of mimosine leaves into cultivated soils may be helpful for the biological control of weeds. The findings of this research reveal that mimosine may be useful for the development of bio-herbicides.