Skip to main content









Donation Heart Ribbon

Customs Agents Stop Fungus At Mexico-U.S. Border

During the last two months of 2009, U.S. Customs and Border Protection (CBP) agriculture specialists frequently intercepted a fungal disease, black leaf spot, preventing it from entering Southern California.

Paul Morris is the director of field operations for CBP in San Diego. He says part of the agency's mission is to find harmful agricultural pests and keep them from entering the United States.

Morris says stopping fungal disease on shipments into the country and at the border helps protect California's multi-billion dollar agriculture industry.

There were 31 interceptions of black leaf spot from November through December 29, 2009.

While interceptions of this fungal disease are expected to be more frequent during the rainy season, this year's interceptions have increased significantly.

In every instance, the pest was found on basil, an aromatic and tender low growing herb that belongs to the mint family. It is grown locally and is also imported fresh into the U.S. year-round from Mexico.

Basil can be infected with this fungal disease, which is commonly referred to as "black leaf spot." Symptoms of the disease include dark brown to black necrotic, often opaque spots on leaves, usually with angular margins. Black spot disease progresses rapidly under favorable conditions such as high humidity, and makes the basil unmarketable.

CBP officers and agriculture specialists enforce hundreds of laws at the border for other federal, state, and local law enforcement agencies.

Following other agency regulations, CBP is required to take action when they encounter black leaf spot. In each case, the CBP said the shipments of infested basil were re-exported to Mexico.

Want more KPBS news?
Find us on Twitter and Facebook, or subscribe to our newsletters.

To view PDF documents, Download Acrobat Reader.