International Allelopathy Society has redefined Allelopathy as any process involving secondary metabolities produced by plants, algae, bacteria, fungi and viruses that influences the growth and development of agricultural and biological system; a study of the functions of secondary metabolities, their significance in biological organization, their evolutionary origin and elucidation of the mechanisms involving plant-plant, plant-microorganisms, plant-virus,
plant-insect, plant-soil-plant interactions.
Taxonomic keys to plant, soil and aquatic nematodes [by] Bruce E. Hopper and Eldon J. Cairns.