(-) Apart from prototyping and testing the approach, you will have to find the best possible way to address (and organize) the vendors. Is there some kind of intermediary structure you can go through? (-) Mobile applications can help not just to impart knowledge, but also help with waste management. There are some value-chain oriented apps for producers that could possibly be adapted to suit your purpose. (-) Improved waste management and reduced waste would already be great, but I agree that you might want to go a step further in helping the vendors increase value addition, be it by drying some of the leftover food, using it for energy generation (some smaller scale options exist already), or processing it further (soups, juices or smoothies - supplying some local market kitchens (?), but also concentrate, essential oils, etc.). (-) Have you thought about how vendors could potentially be financing this (micro finance institutions) or how you could be financing this longer-term (there are many different public and private sector options available)? (-) I can think of a few project examples, where the local market place was leveraged to support entrepreneurship development. Once you start and the project thrives, there are so many good options to expand it further... (-) Quite a few organizations might be interested in this, esp. once you have the prototype (approach).