Sweet potato growers in North Carolina will soon begin the process of planning for their 2012 crop and a big part of that process will be developing a management plan insects — most prominent of these the ever-present wireworm.

North Carolina is the country’s largest sweet potato producing state, totaling nearly half the entire production in the U.S. Despite annual production of 600 million pounds or so, worth more than $175 million, until recently there was no consistent plan for managing wire worms — the leading insect threat to sweet potato production in the state.

Now, thanks to a multi-state research program and the recent addition of Mark Abney to the research and Extension program at North Carolina State University, growers have a uniform program to follow.

Abney worked for a while on a USDA regional sweet potato project to determine which insect pests were causing problems in sweet potatoes. He brought with him to his current position a keen interest in sweet potatoes and extensive knowledge of sweet potato pest management.

Wireworms, which live in the soil and feed on sweet potato roots, are the No.1 insect enemy of sweet potato growers. Left uncontrolled, these insects can cause devastating yield reductions.

Prior to 2006, wireworm management strategies were much the same from North Carolina to Texas. Growers relied almost exclusively on a pre-plant insecticide, most recently Lorsban, followed by up to 12 foliar applications during the growing season. Most North Carolina growers were spraying 4-6 times with a wide array of foliar-applied insecticides, Abney says.

Sometimes, the foliar applications worked, sometimes they didn’t work. The major shortcoming of this long-term management strategy is the treatments didn’t kill wireworms below ground. Adults don’t feed above ground on sweet potato, so the practice was often ineffective.

Nevertheless, growers were compelled to spray because of the high value of the crop and the high probability of wireworm damage.