They are hurt because cotton is one of their exports and a developing nations needs to be able to make money from them so if a big country takes away one of their main exports it will hurt their economy.
Markdown refers to a reduction in the regular selling price of an item. When a trader wants to clear some old inventory or in a sales promotion, they may reduce the regular price to attract more customers. The rate at which the price has been reduced in the markdown.
Markdown can be given in dollar amount. The seller indicates the amount of money that has been knocked off the price. Markdown can also be expressed as a percentage of the regular selling price. In such a case, the new price after the markdown has to be calculated.