Scarring of Nectarine from Thrips Can Be Prevented

Nectarine damage from thrips. Picture from another reader,
not this one.

Q. I have an Arctic Star nectarine but the fruit really looks awful each year. How do I make the fruit look better and is this fruit safe to eat?

A. This particular nectarine is one of my favorite fruits to grow in Las Vegas and it is also one of the more difficult to grow as well. The difficulty is just what you are experiencing. The fruit becomes scarred because of the Western flower thrip.

            But let me say something about the quality of this fruit first. When I first tasted this fruit I was blown away. The flavor profiles are absolutely remarkable when it is grown here in the desert. My best description would be “perfumey”. Now I am not a “perfumey” kind of guy but it has this floral overtone that sets it apart.

Arctic Star nectarine growing at the Orchard. Sprays were
applied to control the scarring from thrips.

             It is a white-fleshed nectarine. Typical, like many white fleshed peaches, I would describe the taste having some almond in the background, very sweet and with these floral (I would call them rose) backgrounds.



            Nectarine is a hairless peach. It was discovered in a peach orchard as a “sport” (mutation) growing on a peach tree. This branch with the hairless peach was propagated by cuttings and then used as budwood to make more nectarines.

            The hair on a peach that some people object to actually adds some protection from insects for the fruit. Tiny insects, like the Western flower thrips, are so small (long and narrow measuring about 1/32 of an inch long) that they have a hard time battling their way down to the skin of a hairy peach.

Scarring from thrips starts at a very early time
in fruit development. Spraying should begin
immediately after flower petal fall.

            However, once that hair is no longer there this insect has no problem getting to the skin of the fruit. Once at the skin, this thrip uses its modified mouthpart to rip and shred at the skin surface and lap up the juice from the fruit much like a dog.



            This tearing and shredding of the fruit skin leaves scarring on the fruit surface as it grows. This scarring is what you are seeing. I have watched thrips start their feeding inside the flowers of peach and nectarine, feeding on the ovary of the flower. As the ovary becomes pollinated and the fruit develops, the hair on the peach keeps the thrip at bay.

 

            However, the hairless peach, the nectarine, does not have this protection and the thrip continues feeding up to harvest. This can cause tremendous scarring of the fruit and it looks so awful no one wants to eat it. It is, however, perfectly safe to eat.

            Control of the thrip on nectarine requires a spray program on nectarines but not on peach. Sprays used in rotation include insecticidal soaps, neem oil and spinosad. I will talk more about control and give some pictures in my blog. Start your spray schedule right after the petals fall from the flowers. Do not spray flowers in bloom...ever. Follow label directions on your sprays. Obey the re-entry period that the label states even though the sprays I mentioned are "organic". However, the most effective spray in the group is the spinosad. Spray the fruit to protect it. Add a wetting agent to the spray to get better fruit coverage.