|Cysts of Globodera rostochiensis, the golden nematode.|
Symptoms typical of potato "soil sickness" had been noted in a field near Hicksville, Long Island in the early 1930s, but it was not until 1941 that the cause was identified as Hederodera rostochiensis (now Globodera rostochiensis). The farm on which it was found had been a staging area for military equipment returning from World War I, and the nematode likely was introduced in mud on the tires of returning vehicles. The population growth of G. rostochiensis is very slow, and it can take 10-12 years to build up to a level that can cause noticeable damage. In the time between its introduction and its identification as the golden nematode, it was spread to other potato farms on Long island through the reuse of burlap bags, the return to the fields of "tare soil" (soil that falls off the tubers during grading and packing), and the movement of farm machinery and vehicles from one field to another.
To limit the further spread of the golden nematode, a State and federal quarantine was established on Long Island in 1944 with the following provisions:
Drums of D-D in preparation to fumigate a golden nematode-
infested potato field on Long Island.
The golden nematode has a slow population growth rate. Following introduction, it takes 5-8 years to build up to the detection level and 8-12 years to reach the damage threshold (about a 10- to 100-fold increase over the detection threshold). This allows plenty of time for the nematode to be dispersed unwittingly by movement of soil adhering to machinery, tires, boots, etc.
Unbeknown to APHIS, a Long Island potato grower sold his farm to a real-estate developer and moved to Steuben County in upstate New York before the quarantine was imposed, bringing with him his tractors, trucks, and all his farm equipment. The golden nematode was found on his Steuben County farm in 1967. That farm was immediately quarantined, and later purchased by the USDA/ARS and established as a golden nematode research farm under rigid security. The farm was surrounded by a chain-link fence with carefully controlled access. Ditches were constructed to manage the surface water run-off.
The grower had not grown seed potatoes, so APHIS officials were not concerned about spread of the nematode to other upstate potato farms. However, it was later discovered that the grower had shared machinery with a neighboring potato grower who did grow seed potatoes and sold his seed to out-of-state growers as well as other New York growers. Upon soil sampling, the seed plots were discovered to be infested, and APHIS began surveys of the soils of as many of the seed customers as they could identify.
In 1976 the golden nematode was detected on potato farms in Wayne County and Orleans County in New York, and these farms were also immediately quarantined. There was another detection in 1983 in Livingston County, New York. As of 2002, 6,000 acres are known to be infested in 9 New York counties, but no golden nematode has been found outside of New York despite extensive soil surveys in 35 states that have commercial potato production.
The APHIS/PPQ quarantine is still in effect in the golden nematode-infested areas, and hundreds of pieces of farm machinery, earth-moving equipment, and vehicles are being treated every year before being allowed to move out of quarantined zones. Eradication of the golden nematode in the US, once the goal of APHIS/PPQ, is now out of the question, and many argue that even the quarantine has reached the end of its useful life. The quarantine, despite a few "leaks," has kept the dispersal of the golden nematode to very low levels and has provided time to develop golden nematode-resistant potato varieties.