Sudan has agreed to take a shipment of food aid after all. The shipment, from the US, had previously been rejected on the grounds that it was genetically modified; the World Food Programme claimed that this was impossible.
It's not unreasonable to assume that food aid from the US might be contaminated with genetically modified food (if you don't know that GM sorghum hasn't been developed); 60% of the land that is used worldwide to grow GM crops is in the US, and a lot of this harvest ends up in food aid (source). But the problem, as the BBC article suggests, may not be the presence of genetically modified material as such, but rather the policy of dumping food in the guise of aid.
Sudan has had a bumper crop this year. It would be well capable of supplying food to the refugees. What it needs is a purchaser and a distribution network. The WFP is well placed to do this. Except it's not.
Donors, particularly rich countries like the US, tend to give food rather than money. It's a great way of getting rid of the excess food produced by the over-subsidised agricultural industry. So the WFP doesn't have any money to buy Sudan's food. Instead, it has to distribute the foreign food, which ends up driving the local farmers out of business when they can't sell their crops.
Jennifer Clapp's paper The Political Economy of Food Aid in
An Era of Agricultural Biotechnology suggests the US also has another motivation for distributing GM material as food aid: in the developing world, countries are generally hesitant to approve the growing of GM food. As they don't have the resources to do extensive testings, they tend to follow the European model of caution rather than the US one of 'innocent until proven guilty'. This means that the market for GM crops outwith North America is very small – unless they can break the resistance by presenting people with a fait accompli.Equally, the developing countries have an economic motivation for refusing GM foods: they might lose their export licences to the EU if any of the food grain is found to have been sown and crossed with local varieties.
Ultimately, of course, the problem is with all food aid, not just that involving GM material, where the food is the result of Western subsidised excess rather than having been sourced as locally as possible. In general, it's better to give money in such situations rather than food.