Chitooligosaccharides and methods for use in enhancing corn growth

A method of enhancing corn plant growth, comprising treating a corn seed and/or a corn plant that germinates from the corn seed with an effective amount of at least one chitoogilosaccharide (CO) and at least one lipo-chitooligosaccharide (LCO) represented by the following formula:

• wherein R1 represents C14:0, 3OH—C14:0, iso-C15:0, C16:0, 3-OH—C16:0, iso-C15:0, C16:1, C16:2, C16:3, iso-C17:0, iso-C17:1, C18:0, 3OH—C18:0, C18:0/3-OH, C18:1, OH—C18:1, C18:2, C18:3, C18:4, C19:1 carbamoyl, C20:0, C20:1, 3-OH—C20:1, C20:1/3-OH, C20:2, C20:3, C22:1, and C18-26(ω-1)-OH (which according to D'Haeze, et al., supra, includes C18, C20, C22, C24 and C26 hydroxylated species and C16:1Δ9, C16:2 (Δ2,9) and C16:3 (Δ2,4,9));
• R2 represents hydrogen or methyl;
• R3 represents hydrogen, acetyl or carbamoyl;
• R4 represents hydrogen, acetyl or carbamoyl;
• R5 represents hydrogen, acetyl or carbamoyl;
• R6 represents hydrogen, arabinosyl, fucosyl, acetyl, sulfate ester, 3-0-S-2-0-MeFuc, 2-0-MeFuc, and 4-0-AcFuc;
• R7 represents hydrogen, mannosyl or glycerol;
• R8 represents hydrogen, methyl, or —CH2OH;
• R9 represents hydrogen, arabinosyl, or fucosyl;
• R10 represents hydrogen, acetyl or fucosyl;
• and n represents 0, 1, 2 or 3, and wherein, upon harvesting, the corn 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 and/or corn plants germinated from untreated corn seed.