The Zakah of Corn, Watermelons, and Trade Goods

Question:
A questioner from Sudan says: He is a trader in corn and watermelons. Is zakah due on them? And what are trade goods?

Answer:
Grains are subject to zakah (the obligatory alms) if they reach the nisab (the minimum threshold for zakah), because they are among the grains. As for vegetables, there is no zakah in them in themselves; rather, the zakah is in their value. So if he sells them and obtains money from them that reaches the nisab and a lunar year has passed over it, he pays zakah on it. Or if he sells in vegetables, buying and selling with vegetables, then this is among trade goods, and he pays zakah on their value by giving a quarter of a tenth of it. Yes.