Field production trials of new downy mildew resistant basil varieties has yielded positive results, promising the herb industry some much-needed relief from this debilitating disease.

These commercially viable downy mildew resistant (DMR) varieties were developed by a team at Rutgers University in New Jersey, spearheaded by Dr. Jim Simon, distinguished professor of plant biology.

The development was further supported by long-time herb pioneers Ed Van Drunen of Van Drunen Farms and Charlie Coiner. Seeds for these DMR varieties are now available from select seed distributors or VDF Specialty Seeds.

Over the past year, these DMR varieties have undergone field trials to ensure efficacy and viability. In a nod to basil being the “herb of love,” the varieties are named Rutgers Devotion DMR, Rutgers Obsession DMR, Rutgers Thunderstruck DMR, and Rutgers Passion DMR.

“At a time when consumer demand for basil is at an all-time high the industry cannot afford to suffer increasing loss due to downy mildew,” says Coiner. “These varieties come at a fortuitous time for growers and the past year’s production and trials prove these varieties yield big when not sick with downy mildew.”

In the 2018 season, Van Drunen Farms planted and harvested hundreds of acres of Rutgers Downey Mildew Resistant (DMR) basil, resulting in tremendous increases in organic and conventional basil yield.

“We saw a 194% increase in organic and a 15% in conventional,” reports David Van Drunen, VDF Specialty Seeds manager. “We expect 2019 yields of conventional to increase 50% since all of the 2018 trials were not able to be harvested.”

Harvest quality and cost reduction were other important aspects. “Leaf quality of the DMR varieties was exceptional with a decrease in leaf damage, spotting, and yellowing,” says Van Drunen.

Full field trials were also performed in Hawaii and other U.S. states in 2018, evaluating the resistance levels of DMR commercial basil varieties marketed by VDF Specialty Seeds.

The University of Hawaii’s Cooperative Extension concluded that considering resistance, flowering, and size, the Rutgers Devotion DMR and Rutgers Obsession DMR varieties are a solution to downy mildew issues facing field basil production in Hawaii.