When D.L. Tuttle died in 2002, the future of his farm hung in the balance.

Daughter Caroline Lineberry had business skills and her father’s meticulous records, but she needed more than that to manage the farm successfully.

Her first step was to do something she had often seen her father do — call Robin Watson, regional agronomist with the North Carolina Department of Agriculture and Consumer Services.

“Caroline is great with marketing,” said Watson, “but after her father died, she was seeking guidance on the field production side of things. I had advised D.L. for about 15 years, especially in the area of plasticulture. I showed him how to grow crops on plastic, how to handle watering and fertilization, and how to use agronomic sampling to optimize yield. Caroline wanted the advantage of that same training.”

To keep the farm going, Lineberry needed to master the production of strawberries, blueberries, tomatoes, pumpkins, cantaloupes and watermelons. Some of these crops require intensive care and critically timed inputs. Watson’s specialty is teaching growers like Lineberry how to optimize crop production through the use of soil testing, plant tissue analysis, nematode assay and other agronomic tests.

Berries and melons may fetch high prices, but their profitability depends on trimming input costs down to the essentials. A pre-season soil test and periodic plant-tissue tests throughout the season give growers precise information about crop nutrient needs so they can apply fertilizer in the most cost-effective manner.

Other agronomic tests can alert growers to the presence of hazardous plant-parasitic nematode populations or indicate potential problems with water sources used for irrigation or for mixing nutrient solutions. The objective of all this testing is to identify and resolve critical issues in a timely way so yields can be maximized and profitable.

Watson walked Lineberry through the process of collecting, documenting and submitting soil samples. He stressed the importance of applying lime and fertilizer based on soil test results. This precaution is especially crucial when growing produce on plastic-covered rows because soil pH cannot be corrected after plastic has been laid, and fertilizers applied through drip tape can be more expensive.

Lineberry followed this advice, but discovered its true value the year she forgot to sample before planting a crop of trellis tomatoes. The field had a pH of about 4.6, which is far from ideal for this crop. Once the oversight was realized, it was too late to put out lime. Crop yield that year barely offset the investment costs.

Has become routine practice

“Soil sampling is always part of my routine now,” Lineberry said. “I need it if I want to make money.”

The first season Lineberry tried her hand at growing strawberries, she collected leaf and petiole samples at 10- to 14-day intervals from March through May. At various times over this period, test results indicated the crop was in need of sulfur, magnesium, potassium, phosphorus or nitrogen. With this information to guide her, Lineberry was able to adjust the nutrient solution mixture so the crop was properly fed. She didn’t waste money by guessing.

“Robin showed me how to take my first tissue sample,” Lineberry said. “He explained how to fertilize and water crops. If I didn’t understand something, he would pull out his calculator and show me the numbers.”

Watson likes to focus on the connection between fertilization and crop quality. In strawberries and melons in particular, nutrition can affect fruit firmness, flavor and disease resistance. In advising Lineberry, he wanted to make sure that she understood the specific roles played by nitrogen, potassium and sulfur. 

“I try to emphasize that excess nitrogen can make fruit too soft,” Watson said. “But growers also need to consider the relative balance of nutrients, as shown on their plant analysis reports.”

A crop with a nitrogen-potassium ratio of 1:2 usually produces sweeter, firmer berries, Watson said, while one with a nitrogen-sulfur ratio of 18:1 or greater may need more sulfur to make use of the available nitrogen. “Applying the right amount of potassium and sulfur is the secret to flavor for melons and strawberries,” he said.

Another challenge Lineberry faced was learning how to manage water inputs. The farm had three different irrigation sources — pond, well and municipal water. Unsure how her father had handled this aspect of production, she chose city water because it seemed easiest. The prohibitive expense of this choice was soon apparent.

Watson recalled that D.L. had watered his larger fields with pond water, passing it first through a sand filtration system to remove sediment and some pathogens. He had used well water on the smaller fields. Watson explained how the filtration system worked and showed Lineberry how to set it up and use it. Then he discussed how to calibrate and time the applications to make sure each crop received the right amount of water.

“Robin is definitely our ‘go-to’ man,” Lineberry said. “If I have a question, I call him. He can always tell me what to do.”

Today, Tuttle Farm is successfully producing all the crops that D.L. used to grow and has added greenhouse tomatoes and deer corn as well. Customers still line up at the roadside market to buy blueberries, strawberries, tomatoes, melons and pumpkins in season. The farm has also become a popular fall destination for school kids, featuring a corn maze, petting zoo, giant hay tractor, hayrides and other attractions.

Watson is one of 13 regional agronomists available to assist North Carolina growers in the diagnosis and resolution of plant nutrient and suspected plant-parasitic-nematode problems. A list of regional agronomists and their contact information is available on the NCDA&CS Agronomic Services Division’s website, www.ncagr.gov/agronomi/.