Copper damage in crucifers, lettuce and
strawberry’s results in small black spots on the plants leaves. This happens when
the concentration of ionic copper in the plants surpasses the plants manageable
level. Copper damage is typically instantaneous with smaller damage spots. Some
factors can increase the likelihood of copper damage by upping the amount of available
copper on plant foliage leading to increased copper uptake. These factors include
the pH of the spray solution, as lower pH values make Copper more soluble. Other
factors are particle size, the frequency of application and rate of solution, water
availability to the plant (more rain higher solubility of copper), age of plant
tissues, product age, copper type, and finally metallic concentration of the
product. All these factors play a role in the solubility of copper and the
development of copper-based injuries on crop foliage. Optimizing these factors
to minimize can therefore prevent copper-based injuries on crops.
By Jordan Etheridge
