A plant pollination control bag 10 defines, in an expanded condition, a space 12 in which a plant part is receivable. The bag defines an opening 14 through which the plant part passes into the space. In the expanded condition, the bag has an end face 16 which is substantially square or rectangular in shape. The bag may include reinforcement arrangements which hold the bag in the expanded condition. The reinforcement arrangement may include a flap 22. The bag may comprise two sheet like members which are joined together to form joints along three edges. The bag may include stiffening in the joints.