Plant Health Inspection by APHA July 2021
Today the 7th July 2021 was the first inspection of the year by our (UK’s) APHA or Animal and Plant Health Agency.
It was a special sort of day, as our inspector was undecided on the leaf and stalk of a Pear (Pyrus) and a Quince (Cydonia) tree. They seemed to have the appearances of Fireblight (Erwinia amylovora).
Extract from Wikipedia – Fire blight, also written fireblight, is a contagious disease affecting apples and pears and some other members of the family Rosaceae. It is a serious concern to apple and pear producers. Under optimal conditions, it can destroy an entire orchard in a single growing season.
Pears are the most susceptible, but apples, loquat, crabapples, quinces, hawthorn, cotoneaster, pyracantha, raspberry and some other rosaceous plants are also vulnerable.
A “Shepherd’s Crook” can be seen when the tip of the shoot wilts, and diseased shoot leaves typically have blackening along the mid-vein and then die. In number, diseased shoots give the tree a blighted appearance.
The 2 images below show firstly an Asian Pear (pyrus) and then a Quince (Cydonia).
The next bit was the most interesting, as I have never seen an in-field test done for Fireblight. Firstly some leaves were gathered, with an emphasis on junction of the dead leaf and live green part. Bits were put into a bottle with a solution in it and a few ball bearings. Cap on and a few brisk hand shakes, to macerate the leaves and extract the juices. A few drops were then pipetted into the eye of the lateral flow test diagnostic sensor. After a few seconds a blue shading appeared on the screen, as soon as it approached the ‘C’ or Control, a blue bar would appear. If it passed this bar all was clear or a negative result.
Both tests proved to be negative. But interestingly, with regards to Covid 19, Boris Johnson (UK Prime Minister) gave the impression that this was new technology, specially designed for Covid. But these lateral flow tests have been used for fireblight testing for years. The only part different is the chemical used for the diagnostics.
