Hi. I work with pears and don't have direct experience with Japanese apricots, but will offer a few comments. One is that there is often a great deal of variability among individual blossoms, and all kinds of deletions or fusions of flower parts occur among the population of blossoms in most fruit trees. Absence of petals or other flower parts, or odd-looking fusions of parts happen regularly in some blossoms on some trees. However, as you suggest, nutrition can play a role in flower health. Nutrient availability to the blossom may affect its size, shape, and likelihood of forming a fruit. In pear, nitrogen is generally important, but also magnesium and manganese. I don't know specifically about the Japanese apricot, but suggest that a fertilizer containing macro and micro nutrients applied to the soil during spring may help support the health of next year's blossoms.

Thank you so much.  I will do it as you advised me.