Fruit trees and vines defoliate after harvest season. The leaves change colour and drop off (Fall)… only some trees tend to hold their leaves and they drop off haphazardly over a long period of time.
Every time a leaf is shed it leaves a leaf scar wound that is essentially an entry point for disease-causing bacteria. So having leaves fall off slowly can leave the tree vulnerable for a long period of time.
Speeding up the defoliation process is preferable, and innovative growers can do this by applying copper as a foliar spray.
Researchers state “Copper is a nutrient required by all plants and copper is often deficient at the end of a growing season however nutritional copper is rarely applied.”
An effective application will cause the leaves to shed within the week generally, and beneficial biology applications will form a barrier over the open wounds to provide protection to the tree from pathogens.
Recent research with regard to leaf scar wounds has led to this practice becoming more of the norm in an effort to alleviate canker disease. Once the leaves have fallen biological products can be utilised to callus wounds naturally; effectively keeping out weather and various diseases (pathogens) that may prevail such as Canker and Silver leaf.
It also promotes an even bud break the following spring and some copper formulations top up the nutritional copper requirements of the plant.
But, surprise surprise, not every copper product works in the same way.
A nectarine grower in the Hawkes Bay conducted an independent trial in 2014 to assess which copper product would defoliate his trees most effectively. He compared Copper Oxychloride and BIOMIN™ Copper.
Initially, the immediate choice was Copper Oxychloride, as at $130 per 10kgs it seemed much more affordable than the BIOMIN Copper at $516 for the same 10kgs (price at the time of trial). But the results from his field trial actually proved that his initial assumption was wrong.
He only needed to apply a third of the BIOMIN™ Copper product (2 kg/ha vs 6 kg/ha) and the results were conclusive that the BIOMIN™ Copper defoliated his trees at 95% within a week, the Copper Oxychloride only 20%.
“I am dumbfounded, this goes to show how systemic your products really are,” reports the Hawkes Bay farmer.
If that doesn’t convince you, then allow me to continue…
Copper is a heavy metal and the use of large quantities of historically sourced copper products for defoliation should be considered carefully if you are interested in the long-term preservation of your soil. The vast percentages of generic copper products used for defoliation are washed to the soil, leading to long-term soil heavy metal contamination.
Copper Oxychloride (one such example) is needed to be used in large quantities for effectiveness, a vast percentage of the heavy metal is washed to the soil, contaminating it for many years to come. The copper can kill off beneficial organisms in the soil that are vital for plant health (and next year’s fruit yield!).
To add to the health dangers of this heavy metal load in the soil, it can contaminate meat of animals who graze on the pastures that have been contaminated by a Copper Oxychloride application. These heavy metals will inevitably end up in the body of those that consume the meat.
BIOMIN™ Copper, on the other hand, is a foliar systemic copper, applied at low rates, that enters the plant leaving no residue. It does NOT increase soil heavy metal levels, due to its uptake efficacy and because it is in a bioavailable form.
And the pictures speak volumes, check out these two different trials, where you can clearly see the effects of BIOMIN™ Copper. #leavesbegone
To read the full trial results, and see images click here:
And another trial to analyse the difference in Copper Oxychloride and BIOMIN Copper for defoliation in Hawkes Bay on Spring Bite Nectarines here…
Shop our BIOMIN Copper product here.