All nursery stock shipped into this state from any foreign state or country must be accompanied by a certificate, dated not more than six months prior to the date of the shipment, or by a written or printed copy of the certificate, attached to each car, box, bale or parcel thereof, stating that the stock to which the certificate is attached has been inspected by an officer duly authorized by the laws of the state where the stock was grown, and that the same was found to be free from dangerously injurious insects and from such as might be liable to become so when introduced into nursery, vineyard, farm or garden.
Every such certificate shall be accompanied by a written or printed statement from the nurseryman shipping the same, declaring that the stock is part of that which was inspected by or under the direction of the officer signing the certificate, and he shall further state whether or not the stock has been fumigated with hydrocyanic acid gas.