Hi Guest,

Given that you have aphids on a food crop you obviously don't want to spray anything toxic, and in fact you don't need to. The short answer to your question is: anything vegetable or plant based.

There's a good article on Ecocharlie with a variety of suggestions:

http://www.ecocharlie.co.uk/blog/index.php/2010/03/08/plant-pests-%E2%80%93-ten-top-organic-solutions

The best options might well be a vegetable-based washing up liquid solution - something like Ecover is ideal - or one of the plant-based home made sprays. I like the idea of using the natural defences of one plant (like Chilli, Garlic, both of which I've used successfully, or Rhubarb, which I've not yet tried) to protect another too.