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We have some lime trees that generally give a good amount of fruit, most of it coming off the tree in good shape.

About 10℅ of the fruit has discolored areas usually on the bottom of the fruit ("bottom" here being relative to the orientation it hangs in). It's not just color either - there is a ridge around the area, as if the peel was thinner there.

Are these still safe to eat?

What causes it?!

Here's a pictures of a couple of limes with the issue:

Two limes with brown regions

Here's one cut in two:

enter image description here

The flesh near the discoloration is softer and perhaps a bit browner in color.

BeeOnRope
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1 Answers1

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By the bottom end I take it you are referring to the blossom or stylar end of the fruit. The appearances you are seeing is called blossom end rot which is caused by a physiological block of calcium uptake and is caused by an irregular watering of the tree. The fruit is safe to eat unless there is secondary infection with Alternaria.

Those fruits already affected can't be cured. It's suggested to place a couple of handfuls of agricultural lime or gypsum around the tree drip line and to ensure that watering is regular especially in hot weather. It can also be caused by too much soil nitrogen which causes growth outpacing the availability of calcium. Some people also suggest the use of a calcium foliar spray to try and correct the problem.

http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=19326

Graham Chiu
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  • Thanks! I'm not an expert in fruit - by "bottom" here I meant the end opposite the stem (which faces towards the ground when the fruit is handing in the tree). How would I identify a secondary infection with alternaria? – BeeOnRope Jan 26 '17 at 18:49
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    You get obvious black rot – Graham Chiu Jan 26 '17 at 23:48