wheat was once a currency

What would you rather have, in the event of a natural disaster gold or wheat?. Well, i would go for wheat, even in a financial disaster. I noticed that the Indian government had stopped futures trading in wheat. Why would they do that? My guess is that they are concerned about too many people/speculators wanting to take physical delivery, as opposed to closing out their position. Maybe there was more futures contracts than there is wheat in India. If so then a similiar problem could arise in other countries. ie US. Just my musing, although i would be interested in which companies in Australia and Canada own more than the odd silo of wheat