Q. My nectarine fruits have this corky appearance on the
outside on their skin. They do this every year. I don’t apply any pesticides. I
sent you a picture. Why does this occur?
outside on their skin. They do this every year. I don’t apply any pesticides. I
sent you a picture. Why does this occur?
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| Nectarine scarring noticed by reader. |
A. I will post your picture on my blog as well as some
others which are similar that are common to nectarine.
others which are similar that are common to nectarine.
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| Thrips damage to nectarine fruit at the UNCE Orchard |
Nectarine
fruit is a hairless peach fruit. Not having this hair on the skin allows a lot
of things to damage the fruit. Hair gives a lot of protection to fruit and
slows down water loss from the fruit as well. When the fruit skin is damaged by
blowing sand, disease, and insects the skin reacts by growing a corky surface
which we could relate to as “scabby”.
fruit is a hairless peach fruit. Not having this hair on the skin allows a lot
of things to damage the fruit. Hair gives a lot of protection to fruit and
slows down water loss from the fruit as well. When the fruit skin is damaged by
blowing sand, disease, and insects the skin reacts by growing a corky surface
which we could relate to as “scabby”.
Instead
of scabby, we call it russeting of the skin. In plants we are probably most
familiar with Russet Burbank potato which has that naturally rough, dark brown,
corky skin.
of scabby, we call it russeting of the skin. In plants we are probably most
familiar with Russet Burbank potato which has that naturally rough, dark brown,
corky skin.
Russeting
is due to damage to the skin. If this type of damage continues, the entire
fruit could be covered with this corky surface. From your picture it appears
that it’s started and then stopped for some reason since it only covers a small
portion of the fruit. So we are looking for something that happened to the
fruit when it was pretty young.
is due to damage to the skin. If this type of damage continues, the entire
fruit could be covered with this corky surface. From your picture it appears
that it’s started and then stopped for some reason since it only covers a small
portion of the fruit. So we are looking for something that happened to the
fruit when it was pretty young.
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| One of the several products that contain spinosad insecticide. Thrips control is difficult. |
The
usual reason for this in southern Nevada would be thrips damage. Thrips are tiny
insects that cause damage to soft plant tissue very early in the spring. If
they are left uncontrolled this damage can cover the entire fruit or even cause
the fruit to drop from the tree. I was
a little confused because the damage was only in a small area of the fruit and
you did not use any pesticides to control them. But with uncontrolled thrips
you would have expected the damage to continue and cover the entire fruit.
usual reason for this in southern Nevada would be thrips damage. Thrips are tiny
insects that cause damage to soft plant tissue very early in the spring. If
they are left uncontrolled this damage can cover the entire fruit or even cause
the fruit to drop from the tree. I was
a little confused because the damage was only in a small area of the fruit and
you did not use any pesticides to control them. But with uncontrolled thrips
you would have expected the damage to continue and cover the entire fruit.
I
forwarded your picture to a friend at Dave Wilson Nursery in California and he
confirmed the thrips damage. You would apply Spinosad insecticide, an organic
pesticide, with the wetting agent so that the entire fruit is protected from
thrips. You apply this immediately after flower petal fall in the spring for
about three applications about a week apart.
forwarded your picture to a friend at Dave Wilson Nursery in California and he
confirmed the thrips damage. You would apply Spinosad insecticide, an organic
pesticide, with the wetting agent so that the entire fruit is protected from
thrips. You apply this immediately after flower petal fall in the spring for
about three applications about a week apart.
Thrips can be pretty nasty as they deposit their eggs into plants via their ovipositor. Growth stunting, damaged leaves, petal discoloration, are all signs that thrips have been feeding on the plants. Though they can damage smaller plants like this, it is rare that the life of a tree or shrub will be threatened by an infestation of thunder flies. To get rid of thrips, thrips treatment must be applied to a garden.