The suitable fertiliser for foliar spray is

The suitable fertilizer for the foliar spray is Urea.
Foliar fertilizers are dilute fertilizer solutions applied directly to plant leaves. As with soil application of fertilizer, the goal of foliar fertilization is to supply plants with the nutrients needed for good growth.
Urea is commonly used for foliar fertilization because of its uncharged, high solubility and it's rapid and efficiently absorbed by leaves. Once urea is absorbed, it's changed into ammonia and carbon dioxide by a chemical called urease, found in the leaves of many plants.