The espaliered Blood Plums have set a huge crop of fruit this year.
This crop will require thinning which is best done when the fruit reach the size of a pea, probably about a fortnight from now. Ideally a fruiting spur such as this should carry only half a dozen fruit maximum.
By keeping crops smaller, aiming for quality over quantity, it becomes easier to manage diseases and pests including by avoiding fruit-fly problems arising from massive amounts of fallen fruit. Rigorous pruning and espaliering the trees allows this "micro-management" of fruit crops. For more on The Espaliery click here