Protection Through Quarantines

Horace S. Dean.

Modern transportation in the air age brings us close in time to lands far distant in point of miles. Travel for business, recreation, and cultural purposes stimulates interest in exotic plants, fruits, and other plant products. Modern commerce and world economy are conducive to an international flow of plants and plant products together with the plant diseases which these materials may carry across international boundaries, including our own.

Were there no barriers to plant disease entry, the United States could readily become the habitat for a host of plant diseases which are not now known in this country and which, if introduced and established here, could become the cause of untold additional annual losses in field crop, fruit, horticultural, floricultural, and forest production.

We take comfort, however, in the provisions of the Plant Quarantine Act of 1912, as amended, by which many safeguards are erected against entry and establishment of foreign plant diseases as well as against the domestic spread of introduced diseases. The safeguards consist of embargo and regulatory provisions in both foreign and domestic commerce. The following remarks relate only to the provisions of the Act concerning plant diseases.

In order to prevent the introduction of any plant disease that is not known in this country or that is not widely prevalent or distributed in the United States, the Act empowers the Secretary of Agriculture to issue a quarantine prohibiting the importation of the host materials of that disease and prescribes certain legal requirements which must precede the issuance of that quarantine. They include a determination of the necessity for the action, and a public hearing on the subject. The quarantine notice must specify the host materials to be excluded and name the countries where the disease occurs. Thereafter, and until the quarantine is withdrawn, the importation of the named host materials from the specified countries is prohibited regardless of the use for which the materials are intended.

All nursery stock not excluded by such embargo action may enter this country only when a permit has been issued by the Secretary of Agriculture for the importation. If the plants are to come from a country with an official phytosanitary inspection system, the shipment is to be accompanied by a certificate of the proper official of the country of origin that the nursery stock has been thoroughly inspected and is believed to be free from injurious plant diseases and insect pests. In the case of importations from countries without official systems of inspection, the shipment shall meet such conditions as the Secretary of Agriculture may prescribe.

Any plants, fruits, vegetables, roots, bulbs, seeds, or other plant products not defined as nursery stock in the Act may be brought under regulated entry comparable to that for nursery stock by action of the Secretary. To do so he must determine that the unrestricted importation of any such plant materials may result in the entry of injurious plant diseases. Other requirements are similar to those necessary to promulgate a prohibitory quarantine.

AN AMENDMENT to the Act that was approved July 31, 1947, improves the protection against foreign plant disease entry by making provision for growing nursery stock under postentry quarantine by, or under the supervision of, the Department of Agriculture, for the purpose of determining whether it may be infested with plant pests not discernible by port-of-entry inspection methods. Should there be such infection, the Secretary is authorized to prescribe remedial measures to prevent the spread. This feature is particularly useful in the instance of virus diseases.

THE VARIOUS QUARANTINES and orders issued under authority of the Act and now in force cover practically the entire field of foreign host materials plants and plant parts, including fruits, vegetables, seeds, several fibers, and cut flowers likely to carry injurious plant diseases into this country. Several of the quarantines and orders are issued under authority of both the prohibitory and regulatory parts of the Act.

A number of the foreign quarantines contain provisions complementing domestic plant disease control programs. For example, a feature of Nursery Stock, Plant, and Seed Quarantine No. 37 regulates the entry of barberry seeds and plants in harmony with the provisions of Federal domestic Stem Rust Quarantine No. 38. Another feature of Quarantine No. 37 prohibits the entry of citrus seeds into Florida, where there is a comparable State quarantine against citrus propagating materials from other States.

The quarantines and orders are enforced by plant quarantine inspectors at the principal ports of entry. The inspectors are assisted through cooperative relations by their associates in the Customs, Immigration, Public Health, and Postal Services, and the Bureau of Animal Industry and by collaborating State plant quarantine services. The total effort of those services and the foreign inspection and certification of plants before shipment provide an effective program for the enforcement of the quarantines and prevention of the entry of plant diseases. Carriers and cargoes, mail, and baggage from foreign countries are examined for unauthorized plant material.

The plant material that is permitted entry into the United States is inspected for the presence of plant pests. The more hazardous of the plant propagating materials that are permitted entry are routed, upon arrival, for intensive inspection at specified locations where specialized facilities are available, both for inspection and for whatever treatment is required. These facilities are maintained at Hoboken, N. J. (in the Port of New York); Miami, Fla.; Laredo, Tex.; San Francisco and San Pedro, Calif.; Seattle, Wash.; Honolulu, T. H.; and San Juan, P. R. Certain designated kinds of plants are then released only for growing by the importer pending further observation for plant pests particularly virus diseases not detectible at the time of entry.

Not all importations are inspected with equal thoroughness because that would be too costly and, according to experience, unnecessary. The Department therefore places greater emphasis on the inspection of some classes of plants and plant products than on others (according to known or potential risk of entry of plant diseases) in order to afford the maximum degree of protection possible with the facilities available. The State plant quarantine agencies support the Department in connection with the postentry quarantine work by assuming the primary responsibility for the growing-season surveillance of imported plants held under postentry quarantine conditions. Certain States contribute materially to the entry control program at ports of arrival.

The Department itself makes numerous importations in connection with its program for improving field and vegetable crops, the horticulture, floriculture, and forestry of the country, and for kindred experimental and scientific reasons. These introductions, which may legally include material prohibited entry, are subjected to even more rigid control and safeguards on entry than are introductions by the public.

As to domestic commerce, the Act in some respects is more adaptable to the needs of a program for prevention of the spread of plant diseases because it gives the Secretary authority to embargo or regulate the movement of "stone or quarry products, or any other article of any character whatsoever, capable of carrying any dangerous plant disease," as well as authority to embargo or regulate the movement of nursery stock and other plants and plant products.

In a manner similar to the procedure prescribed in the field of foreign commerce, the Secretary may quarantine any State, Territory, or District of the United States, or part thereof, whenever he determines it is necessary to do so in order to prevent the spread of a new or not yet widely prevalent or distributed dangerous plant disease. He is directed, when public interest will permit, to provide by regulation for the inspection, treatment, and certification of the regulated materials in order to govern their movement from the quarantine area.

Unless the Secretary has issued a quarantine to prevent the domestic spread of a dangerous plant disease, the Act specifically provides that a State, Territory, or District may enforce a measure for the same purpose. The Secretary has discretionary authority also to cooperate with States to carry out their quarantine measures.

The quarantines and regulations governing the domestic movement of plant materials may be divided roughly into' two classes those governing interstate movement on the mainland of the United States and those governing movement between the off-shore territories and possessions and the mainland, or other off-shore territories and possessions. These domestic quarantines on the mainland are usually associated with disease control projects of the Department.

The States help materially in carrying out these projects, including enforcement of related intrastate quarantines. Further assistance in the domestic quarantine enforcement is derived from the inspection by Federal inspectors of shipments of quarantined materials moving interstate through traffic centers. Although the Act provides for such protection, practical enforcement problems resulted in lifting the only quarantine of the mainland for the protection of an off-shore area. Only three quarantines of offshore areas exist which are designed for plant disease reasons to protect the continental United States; namely the quarantine (No. 16) of Hawaii and Puerto Rico on account of sugarcane diseases, and the quarantines of Hawaii on account of citrus canker (Nos. 13 and 75).

THE ACT also makes especial provision with respect to the District of Columbia in order that it may have a plant quarantine inspection service similar to that of the States and Territories. The Secretary of Agriculture is authorized to make regulations to govern the movement of plants and plant products into and out of the District "in order further to control and eradicate and to prevent the dissemination of dangerous plant diseases." This part of the Act also confers authority to compel an owner to take sanitary action in case of a nuisance situation to prevent the dissemination of plant disease.

HORACE S. DEAN, a graduate of the University of Tennessee, entered the employment of the Federal Horticultural Board in Washington, D. C., as a plant quarantine inspector in 1923. Except for a brief period as a plant pathologist in Central America, he has worked continuously in the field of Federal plant quarantine, with special emphasis in later years on program administration. He is now assistant division leader of the division of plant quarantines, Bureau of Entomology and Plant Quarantine.