Taking matters into their own hands, Crop-Tech Consulting employees Thomas Zerebny (left) and Zach Ferrie developed a micronutient-symptom growout experiment.
Step-by-step guide to identify lacking micronutrients
Micronutrients are essential for plant health. You can apply a micronutrient mix that, you hope, will prevent problems or you can learn to identify the symptoms and treat only if you find a problem. Farm Journal Field Agronomist Ken Ferrie recommends the latter approach.
"Micronutrient deficiencies can be serious—if you have them," Ferrie says. "But problems with micronutrients usually are driven by some other condition, such as compaction, drought, organic [muck or peat] soils, sandy soils and acid or alkaline soils. If possible, solve the micronutrient issue by fixing the underlying cause.
"The environment tells us where to expect micronutrient issues," he adds. "Elsewhere, it’s rare to find a problem."
Neither crop scouting, soil testing nor tissue testing is sufficient, by itself, to diagnose a micronutrient deficiency. It requires a combination of all three.
Take the detection process step by step, Ferrie says.
Diagnosis begins by knowing the symptoms of various deficiencies well enough to spot a problem. Determining whether symptoms appear at the top or the bottom of the plant eliminates half of the possibilities.
The Micronutrient Deficiency Detection Guide will lead you through the detection process. The first step is to rule out macronutrient (nitrogen, phosphorus and potassium) deficiencies, then evaluate micronutrient issues.
Micronutrients to Monitor
Here are capsule descriptions of the micronutrients most likely to cause problems, according to Farm Journal Field Agronomist Ken Ferrie.
Boron is involved in cell division, viability of pollen grains, and the formation and metabolism of carbohydrates. But its biggest impact is on water metabolism. "If boron availability in the plant is low, it can have trouble taking up water," Ferrie says.
Boron deficiency also can be triggered by excess potassium and calcium in the soil. Deficiency symptoms in plants are difficult to identify because the individual symptoms mimic those of other nutrients.
Symptoms include scattered white spots between the veins on the youngest leaves, which eventually form 2" or 3" long stripes. Plants will have shortened internodes, difficulty unfurling the whorl and rippling at the leaf edges. On older leaves, you will see scorching along the edges. At harvest time, you will find banana-shaped, poorly filled ears.
Copper affects chlorophyll formation and enzymes involved with photosynthesis and disease resistance. Because it plays a role in the development, release and survival of pollen, it is
- February 2012