Source:  NCDA&CS, 6/10/20


From grapes to cotton, tobacco to Christmas trees, any crop can be harmed if the wrong herbicide or pesticide is sprayed on it. Certain specialty crops are especially vulnerable because they can be damaged by lots of normal herbicides and pesticides that are commonly used on farms and yards across North Carolina. Beehives could also be wiped out if certain pesticides drift from nearby. So a registry called DriftWatch is available to help prevent those crops and beehives from being destroyed by drifting chemicals.

Now that hemp is a legally grown commodity in the U.S., it has been added to the list of specialty crops in the Driftwatch registry.

As more farmers and others become interested in growing hemp in the state, the Structural Pest Control and Pesticides Division of NCDA&CS hopes more growers and pesticide applicators will use the registry to protect the crop.

“If hemp growers use Driftwatch to map their sites, others will be able to see where hemp is grown in their area and cut down on any drift damage,” explained Patrick Jones, Deputy Director of Pesticide Programs.

Dr. Angela Post, the N.C. State Extension small grains specialist, says hemp is quite susceptible to many different herbicides, including but not limited to anything that injures other broadleaf crops, any “Group 2” herbicides and hormone herbicides such as 2,4-D and dicamba. Those are all common herbicides used in North Carolina fields.

Just like any other crop, protecting hemp from damage is protecting the grower’s income. Damage to the plants caused by drift isn’t the only concern though, especially with hemp. Even if an herbicide doesn’t damage the hemp, traces of chemical could contaminate it.

Right now there are very few herbicides or pesticides that are approved to be used on hemp. So either by choice or by lack of other options, most hemp growers use only certified organic “minimum risk” (sometimes called 25(b)) herbicides and pesticides. Many hemp processors test hemp for foreign substances before making products out of it.

“There are no tolerances for hemp, so if conventional herbicides or pesticides drift onto it, it may not be able to be sold because they shouldn’t be found on the product.”

The desire to protect hemp and its North Carolina growers is the reason Jones hopes more growers will register their hemp fields and greenhouses in Driftwatch. He said it can be especially helpful to pesticide applicators who are hired from out of state or who work for large entities spraying highways, railroads or power lines (e.g., DOT, railroad or power companies). Often they may not know that a vulnerable hemp field is nearby. While it’s generally believed that local farmers will be more familiar with any hemp growing nearby, that’s not necessarily the case these days.

“These days farmers are going to so many different areas, in and out of counties and such,” Jones said. “So they may not be familiar with everything that’s being grown. If they use Driftwatch they can see any registered crops they could potential damage with drift.”

The statewide DriftWatch map for N.C. shows registered fields and the prevalence of beehives and apiary registries. The map can zoom in to specific areas with a satellite view also to give an aerial view of fields.

Much of the effort so far in North Carolina has been to get growers with specialty crops registered in Driftwatch. The idea is that the Driftwatch map needs to have the crops on the map first before it will be useful for pesticide applicators. Hemp was just added to the registry last fall, and a quick check of the N.C. Driftwatch map shows only three registered hemp fields in the state – all in the northeastern corner.

Only three hemp fields in N.C. are registered with Driftwatch right now.

As of February, there were 1,413 licensed growers in North Carolina with 17,427 licensed acres and 6,819,662 licensed square feet of greenhouse space. So participation in Driftwatch could obviously be better Jones said.

Overall, the state’s participation is much better than many other states in the country. Jones said the most recent figures show 468 specialty crop fields covering 10,549 acres in North Carolina are registered in Driftwatch. Beekeepers have been the most active adopters. There are 2,027 apiaries with 11,147 hives registered. Only 354 applicators have registered, but they can always check the registry map without actually signing up.

More information about DriftWatch, including how to sign up and use the registry, can be found on a special page of the NCDA&CS website that focuses on pollinators.