Now. In my experience, one of the many reasons that makes poor a poor farmer is coping with a non-functioning market (I said it two posts ago). So I can just imagine how helpful would be to have a tool to make market work better.
Creating a wiki page to collect and share the price of one particular agricultural product in one particular time in one particular place would be great. But succeeding in integrating such a site with the mobile phone network would be even better. How to do this? The government of Rwanda is moving in the very same direction without creating a wiki site. (It is difficult to imagine a government managing wikis). But bureaucracy is not something we usually associate with the words efficiency and effectiveness, especially in poor countries. And in any case we do not really need a government to make a site like this work.
Just think about a wiki site collecting and sharing data through sms. Actually Twitter, without the wiki interface, is doing it right now. So, think about a farmer receiving a message with updated price information the night before market day and, on this information, taking his/her decisions. And think about a farmer sending via sms the price information to the wiki site after leaving the market.
We can imagine the farmer to pay for the sms he or she receives and, on the contrary, we can imagine sending sms back to the site to be completely free. And we can imagine some volunteers to be the administrators of the site (just like Wikipedia).