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Wednesday, May 25, 2011

Almonds Turning Yellow and Dropping

Almond Nut Sap Oozing and Dropping
Q. I'm having an awful time with my almond trees. I have two and they are about 8 years old. Last year my tree had large almonds and was just covered with nuts. Well, I lost all of them. They have a see through something coming out of them and then they open and have this yellowish design on the inside. Then they drop. In the meantime my almonds are falling off. So far this year I applied Volck Oil Spray when they were dormant and two weeks ago I applied a fungicide.

A. Thanks for your pictures. Several people have visited with me about the same problem. The squiggly resin coming from the nuts is usually a sign of feeding damage by insects which have mouthparts like a hypodermic needle. They stick this needle into the skin of the nut or fruit, feed on the sap and withdraw it. When they withdraw the needle it leaves a hole in the skin and sap comes out and dries in the squiggly clear resin that you see.

Leaffooted Plant Bug

Sometimes the feeding damage by these insects can cause the nut or kernel not to form. This can result in husks with no nut and the almond yellows and falls from the tree. If this happens to a few nuts and hundreds still remain on the tree then it’s no big deal. But if this happens to hundreds of nuts then this is a big deal.

One of the culprits is the leaf footed plant bug or one of its relatives and you should keep an eye out for this pest. It is a bad one.

Another possibility could be a lack of pollination due to low temperatures during flowering or a lack of good fruit set. We did have some late freezes and if the flowers were open during freezing temperatures it might be possible they were damaged and you lost some of your crop. I do not believe you needed a fungicide spray. My strongest hunch is an insect problem if this happened to you two years in a row.

2 comments:

  1. I have a ten year old Russian almond. This year it was covered in flowers, followed by tiny fuzzy fruit. Within a month the fruit had turned yellow and dropped. I haven't seen any sign of insect damage. We live in zone 2/3 Alaska. This happens every year.

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  2. This is most likely lack of pollination. Almonds may start growing without pollination but will not continue to develop because the kernel or the nut fails to develop so the fruit or fuzzy almond first yellows then aborts. Most almonds need a pollinator or they will not set almonds. There are a few which do not but the majority do.

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