What was the effect of the ming emperors disallowed foreign exploration?

Simply to create a scarcity of the goods involved and a 'black market'.

The intent: To exclude foreign ideas & influences was only partly successful.

its b wells tried to fight lynching in the south by

the option which was not a function of missionaries in the northwest was the first one - they established posts for trading furs and other goods.

missionaries were sent around the world to spread religion and their knowledge and others - they were not merchants who sold furs and other goods.