A plan for tissue testing to preserve top yields
Are Ontario cash crop growers making effective use of tissue testing to enhance yield and crop performance?
The answer requires a little perspective says Jack Legg, agronomist with Guelph-based SGS Agri-food Laboratories. Tissue testing, which provides an accurate measurement of the nutrients within a plant at a given time, has traditionally been used to confirm a problem or issue in a field. Typically, the test is used to verify visual symptoms and then identify courses of action to address problems and save yield.
Perennial U.S. corn and soybean yield contest winners like Randy Dowdy and David Hula employ tissue testing in a different manner. Last week at the SouthWest Agricultural Conference, Legg described how these yield kings have established weekly tissue testing programs to understand nutrient utilization in their crops throughout the season, and respond to the high-yield needs of the crops. “Really what they are doing is paying attention to their crops,” says Legg, who notes that with irrigation and fertigation these growers have the ability to make the required nutrient adjustments throughout the growing season.
Legg tells RealAgriculture’s Bernard Tobin that lack of irrigated crop land limits the ability of Ontario growers to follow the yield script written by Dowdy and Hula, but there are still options for making the most of the test. He notes that growers do have the ability to get into fields with high-clearance equipment to address the nutrient needs identified by a tissue test. (Story continues after the video.)
When it comes to feeding crops for optimum yields, Legg says understanding critical minimum nutrient values is key. He explains that these values indicate the level of plant nutrients that are required to produce 90 percent of achievable yield, and can be measured at key growth stages such as soybean flowering or corn tasselling.
In the video, Legg also stresses the importance of effective tissue testing sampling, including how, where, and when to sample, the importance of representative sampling, testing the appropriate portion of the plant, and gathering adequate material for testing.