What is pear virus?
Pear virus diseases can cause a number of problems on pear, such as Decline, Stony Pit, Pear blister canker, Apple rubbery wood, Apple chlorotic leaf spot, Ring pattern mosaic, Vein yellows and others. For most of them, a virus is suspected but there is no certainty.
One of the most visible virus diseases is Stony Pit, in which fruit becomes misshapen and pitted, and the flesh become hard and gritty. Other typical pear virus symptoms may also be observed in conjunction with stony pit, such as bark cracking, reduction of vigour, chlorotic vein banding or leaf mottling. In fact it is possible that some of the viral diseases listed above are caused by the same virus. In any case, most virus diseases also reduce tree vigour and cropping.
Transmission occurs when infected scion wood is propagated in the nursery when grafting the scion onto the woodstock, or when infected pollinator wood is grafted onto an existing tree in the orchard or garden. It seems that pear virus diseases are not transmitted by seed, pollen or insects.
How to treat pear virus
The best and only treatment for pear virus is prevention. When you plant a pear tree, buy a certified virus-free tree. If you have an infected tree, consider grubbing it and removing it from your garden, replacing it with another type of fruit tree (don’t plant a new pear in the same position of the old pear).