Disclosed are methods of enhancing plant growth, comprising treating plant seed or the plant that germinates from the seed with an effective amount of at least two lipo-chitooligosaccharides, wherein upon harvesting the plant exhibits at least one of increased plant yield measured in terms of bushels/acre, increased root number, increased root length, increased root mass, increased root volume and increased leaf area, compared to untreated plants or plants harvested from untreated seed.
