Jan 18, 2019

Sap analysis an option for winter tomato growers

Beyond simple field scouting, there’s another way to check up on high-value crops.

New Age Laboratories, based in South Haven, Michigan, does analysis of sap pressed from plant leaves and petals.

“It’s like taking a blood sample from a human, but we’re taking a blood sample from a plant,” said Scott D. Wall, president of New Age. “We’re looking at the soluble nutrients that are in transport in the plant, and that are available for metabolism in that portion of the plant’s life cycle.”

Many of New Age’s clients are blueberry growers in its region of southwest Michigan, but Wall said they’ve also performed sap analysis for cherries, grapes and apples. The lab is also reaching out to growers of high-value vegetables such as winter tomatoes and peppers.

Few others offer similar services in the U.S. Some university labs, such as Cornell University’s Nutrient Analysis Laboratory, offer plant tissue analysis services including sap analysis, although not on a commercial basis.

NovaCropControl, based in the Netherlands, specializes in sap analysis and Crop Health Labs in Bellville, Ohio, is the North American provider of its technology.

“Because the tests are not time-consuming, adjustments on fertilization strategies can be done quickly,” according to NovaCropControl’s website. “This helps to avoid nutrient deficiencies or excesses in plants.”

Once the nutrient levels in the sap are analyzed, they can be compared to benchmarks for plant performance.

“It’s one thing to be able to analyze the sap,” Wall said. “It’s another to know where should we be targeting, particularly depending on the growth stage of the plants we’re working with. Are we talking about flowering? Are we talking about pre-flowering? Are we talking about fruit set? And where are our optimal ranges for calcium, potassium, nitrate levels in the sap, in those moments? Plant sap analysis is all about getting the optimal ranges in the plant itself at the right moments during the production period in that year to get an optimal return on investment.”

New Age is able to check sap analysis data against a database from Australia’s Hortus Technical Services that shows the optimal nutrient ranges for a broad spectrum of crops.

“It’s giving us a key tool to optimize the metabolic functions of the plant for maximizing productivity in that production year,” Wall said.

A timely analysis of the plant sap can lead to crop-saving adjustments in the orchard, vineyard, or block of blueberry bushes. For example, a sap analysis of a block of Honeycrisp apples could examine potassium and calcium uptake, in an effort to avoid bitter pit. Honeycrisp that is identified as aggregating too much potassium, rather than calcium, might be ready for an intervention with manganese.

In another case, the lab helped rule out a lack of nitrogen as a possible cause of a fungus outbreak in a vineyard.

Modern growers generally welcome opportunities to take unknowns and uncertainty out of their work.

“It’s not our job to sell them nutrients,” Wall said. “It brings about science to crop management. We no longer have to take it on the salesman’s word that this is the right product.”

Wall said he sees the technology as having a growing impact on the specialty crop industry.

“As we get the word out, it’ll have a wide-ranging influence in a lot of different areas,” Wall said. “The higher value of the crop, the more important it will be.”

– Stephen Kloosterman, VGN Associate Editor

Above: Automatic analyzing machines at New Age Laboratories. Photo: New AgeHELM’s