So I thought this may be of interest to some people - I should have photographed more throughout the grow!
Anyway, this little fella popped up 2 weeks after I planted an autoflower seed. This really bugged me for a while, i couldnt understand what it was and as it grew bigger it made the fabric pot go a whitish colour and as a result the plant suffered.
I had filled the pot with Coco Coir, before wetting the soil out of laziness I said I would do it tomorrow. I had lay this pot right next to a cactus plant. The following day when watering and planting the seed it was also in very close proximity to the cactus. Due to the spikes that have grown, I am leaning towards the idea of it maybe being that one of the cactus spikes fell into the soil or something!
Any other ideas or knowledge on what this is would be brilliant! I can answer any questions to the best of my ability.