The subject matter of microeconomics primarily focuses on the individual economic agents and their decision-making processes. It analyzes the behavior of households, firms, and industries in the allocation of limited resources to satisfy unlimited wants. Microeconomics deals with various economic concepts, such as supply and demand, market structures, production and cost analysis, consumer behavior, and resource allocation.

The options provided in the question are related to different aspects of microeconomics. Let's evaluate each option to determine which one is not a subject matter of microeconomics:

1. The price of mangoes: This is a relevant subject matter of microeconomics as it involves the interaction of supply and demand in the mango market. Microeconomics studies how the price of goods, including mangoes, is determined by the forces of supply and demand.

2. The cost of producing a fire truck for the fire department at Delhi, India: This is also a subject matter of microeconomics. It falls under the category of production and cost analysis, which examines the factors influencing production decisions, costs, and efficiency of firms.

3. The national economic annual rate of growth: This subject matter is not within the scope of microeconomics. It belongs to the field of macroeconomics, which focuses on the overall behavior of the economy, including factors like national income, aggregate demand and supply, inflation, and economic growth. Macroeconomics deals with the economy as a whole, while microeconomics concentrates on individual economic units.

4. The quantity of mangoes produced for the mango market: This is also a subject matter of microeconomics. It involves analyzing the factors that determine the quantity of mangoes supplied to the market by producers. Microeconomics examines the relationship between price, quantity supplied, and other influencing factors.

In conclusion, the subject matter that is not a part of microeconomics is "The national economic annual rate of growth." It belongs to the field of macroeconomics, which studies the behavior of the economy as a whole, rather than focusing on individual economic agents and their decision-making processes.