Pesticide residues in international markets
A review for cherry growers.
Fruit growers understand that the use of pesticides according to label directions is essential to assure that any resulting residues of that pesticide are at or below legal limits on the fruit at harvest. This allowable residue is called a tolerance in the United States, or a maximum residue limit (MRL) in other countries (see “MRLs in Europe”).
Legal use of a product under labels established by the U.S. Environmental Protection Agency generally meant that the product was acceptable to consumers everywhere. Historically, however, there were certain export markets that had unique chemical restrictions, involving one or two chemicals. To prevent problems, growers and packers largely avoided all use of these materials to ensure market access and ease fruit segregation. However, in recent years, that comfortable scenario began to change, driven by increased consumer concerns and greater attention to technical trade rules under the World Trade Organization’s Sanitary and Phytosanitary Agreement.
In many countries, our customers and/or their governments began to take a more restrictive look at the pesticide residues remaining on imported food products. This created a situation where residues of a certain chemical might be acceptable for one market but not for another. Given that growers do not necessarily know where their crop will be sold, the problem is complex.
Of particular interest to sweet cherry growers are two Pacific Rim markets and the challenges that their MRL rules present to fruit exporters and organizations such as the Northwest Horticultural Council, tasked by our members to work on pesticide-related issues:
About ten years ago, customers for U.S. cherries in Japan began asking questions about the pesticides used on the cherry crop. The reason for these questions was a general increase in residue violations on produce exported from trading partners in the region along with the reality that Japan had a very limited list of MRLs for sweet cherry. When residue testing in Japan detected crop protection chemicals that were not on the Japanese list, these detections generally did not result in official rejections of a cherry shipment because Japanese officials would defer to international or exporting country standards when theirs were lacking. However, this deference was not official policy, and the lack of clarity in how MRL detections were regulated was a cause of concern to our Japanese retail customers.
Beginning in 2006, Japan established a comprehensive MRL standard. How this positive list was developed could be a model for all countries in the region. Through a series of international notifications over a three-year period, Japan gathered input from its trading partners as to the MRL values needed. Using a combination of Japanese MRLs, international standards set by Codex, and MRLs requested by trading partners, a comprehensive provisional list was established. While the values set by the Japanese government do change as these provisional MRLs are reviewed and new MRLs are added, to this point, there have been no violations by U.S. sweet cherry shippers while growers appear to have the necessary pest control options. However, the system has not worked as well for all U.S. commodities exported to Japan. Penalties for MRL violations, when they occur, are onerous and the subject of continuing concern by the U.S. government and grower groups. Given the seriousness of the Japan penalty matrix, cherry growers, pest control advisors, and exporters should be aware of any changes in Japan MRLs as the growing season begins.
If Japan’s methodical approach to establishing a comprehensive MRL list is to be applauded, on the opposite end of the trade friendliness scale has been the process used by Taiwan to establish and enforce its MRL policies. Taiwan has periodically moved to establish MRL surveillance programs without first establishing a comprehensive MRL list. Taiwan has a limited MRL list, but unlike markets with similar limited lists, that country does not defer to Codex when an MRL does not exist.
The latest Taiwan episode, currently still in play, began last January with the unannounced testing of imports which resulted in the rejection of 11 containers of apples upon arrival in that country. The loads in question were treated with crop protection chemicals approved in the United States, but without Taiwan MRLs. While the impact on cherry shipments later in the year could have been greater, had not the industry recognized the potential jeopardy, still three shipments and thousands of cartons of cherries from the Northwest were rejected during the 2009 season. Some growers suffered collateral damage as they struggled to avoid the use of certain pesticides without MRLs in Taiwan, resulting in the use of less effective control alternatives that negatively affected powdery mildew control.
As NHC staff began to recognize the specifics of the concern for cherry exports in the spring of 2009, the industry was advised that the use of Provado (imidacloprid), Actara (thiamethoxam), malathion, and Gem or Flint (trifloxystrobin) was especially risky given their potential use patterns and their specific targeting in Taiwanese testing programs. Since that time, both imidacloprid and trifloxystrobin have been granted appropriate MRLs in Taiwan, along with a number of other critical insecticides and fungicides. Thiamethoxam and malathion still do not have MRLs for sweet cherries in Taiwan.
The Northwest Horticultural Council, along with a number of other specialty crop organizations under the umbrella of the Minor Crop Farmer Alliance, continues to engage Taiwan’s Department of Health with a goal of improving that country’s approach to MRL establishment and testing. This effort is receiving substantial support from USDA’s Foreign Agricultural Service, the Office of the U.S. Trade Representative and the U.S Environmental Protection Agency, which is greatly appreciated.