Nitrogen fertilizers foliar

Methods of Mo application include soil application of Mo fertilizer alone or with phosphorus (P) or nitrogen-phosphorus-potassium (NPK) fertilizers (molybdenized fertilizers), foliar sprays, dusts, and seed treatment. 

Carrow, J. R. and Betts, R. E. (1973) Effects of different foliar-applied nitrogen fertilizers on balsam wooly aphid. Can. J. For. Res., 3, 12-39. 

As a fertilizer, urea is a convenient form for fixed nitrogen and has the highest nitrogen content (46% by weight) available in a solid fertilizer. It is easy to produce as prills or granules and easily transported in bulk or bags with no explosive hazard. It dissolves readily in water and leaves no salt residue after use on crops and can often be used for foliar feeding. 

The most popular nonpressurized nitrogen solutions are prepared from urea and ammonium nitrate and contain between 28 and 32% of nitrogen. No special equipment is needed for their storage and application they are easier to mix and to handle than solids, have low distribution losses, can be accurately placed, are suitable for foliar and aircraft application, and are excellent carriers of micronutrients as well as of pesticides and herbicides. As a result, about 60% of U.S. fertilizer nitrogen is now applied in fluids, and the use of solutions is becoming also more widespread in Europe. ... 

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