The present invention is directed to a method for enhancing the rate of formation of the reaction products of a carboxylic acid and a urea having the formula: where R1, R2, R3 and R4 are the same or different and are selected from the group consisting of hydrogen, substituted and unsubstituted alkyl, allyl, vinyl and alkoxyl groups having from 1-6 carbon atoms, substituted and unsubstituted phenyl groups and the halides. The rate of formation is enhanced by adding acid to a solution including the carboxylic acid and the urea. Preferably, the reaction product of the present invention is N,N&prime；-diformylurea or N,N&prime；-diacetylurea. These reaction products, e.g., diformylurea, have been found to produce significantly improved growth in a variety of agricultural products when applied to the seed, to the surrounding soil or to the foliage of the emerging plant.
