Just sew some appropriate black webbing type stuff over the tear (maybe even take a bit if the pole and file it smooth. Use a strong black synthetic thread (not cotton which might rot) and don't worry too much as it's very unlikely to show up against the black background so you can just do it by hand. It might be a lot to get a needle through so use a pair of pliers to push it through and pull out the other side. As my Mrs says, when I sew something, it might not look pretty but it never comes apart.