Sunday, September 9, 2012

Why are my Apples Falling Off the Tree?

I returned home from my vacation in mid-August and was surprised to see apples on the ground.

Why are those apples on the ground in August?
While it is close to apple harvest season, most of our crop doesn't start to ripen until late September.  This was a full month ahead of schedule.  A quick check confirmed it wasn't just one tree either.  It seems every tree in the orchard (over 20 trees) were losing their loads.

It's been a funny summer, hot and desperately dry.  Was it possible the apples had actually matured earlier than normal and were dropping off due to ripeness?

These apples are bright red and LOOK ripe
Taste tests revealed otherwise.  They are hard and bitter and suitable only for the compost heap.  Close inspection revealed a few other details.


If you take a close look at the photo above you'll note some issues.  This apple is small and lumpy with odd blackish streaks on the skin.  Others were mishapen.


So why are almost full size unripened apples falling right before harvest time?  and why do they look so deformed?

I had a suspicion but I needed to check the internet first to be sure.  I have noticed other plants, most obviously the dahlias, were not producing flowers this year.  The only difference from other years is lack of water.

And sure enough the internet confirmed my instincts.


Apple trees often drop their fruit in June (see my post on June Drop), dropping any excess fruit the tree cannot support throughout the season.  Back in June this year things were proceeding along quickly but normally.  The trees had bloomed in May and by June fruit was forming.  The weather was warm but there was still some rain in the forecasts.

Blooms in May
That changed though.  By July the temperatures were consistently in the mid to high twenties (celsius) and no rain was coming at all.  That got worse in August as the temperatures climbed higher and humidity set in, still with no rain.

What has happened to our flowering plants and our apple trees is that flowers and fruit require water to form.  In the case of fruit it requires a lot of water.  When you bite into an apple what is it you first taste?  Juice.  Juice that is derived from water.  But plants also require water in order to survive.  Similar to June Drop, the trees have chosen to keep water sources to save themselves and are dropping fruit they cannot support.

Cleaning up the fallen fruit
But why is this happening so late in the year?  What the internet confirmed for me was that apple drop, just before harvest, is common on trees affected by water stress.  The trees don't know when it will rain again so they hold out, producing fruit and only dropping it when it becomes clear they can no longer support it.

As for those small, awkward looking, lumpy apples.  I discovered that orchardists check fruit circumference and condition throughout the season as a measurement of water stress.  Had I bothered to look earlier I would have noticed this as a clear indicator of water stress.  Something for me to note in future years.

26 comments:

  1. This was fascinating about plant responses to growing conditions. Distressing, though, as your harvest fails. I imagine there was no way you could even have watered so many orchard trees all summer. So sad, but what a great lesson in botany!

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    1. Hi Laurrie, you're right, watering is out of the question so there's no way we could have done anything about this even if we had known. but as you mention, it was a good lesson to learn.

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  2. Marguerite when I read your heading the first thought that came to mind was your dry summer, I've heard and read that plants don't flower and fruit when there is a lack of moisture or drop flowers and fruit they had started to form, a shame but at least your trees are saved to flower and fruit in the coming years, Frances

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    1. When I was reading up on this I actually read that drought one year can affect fruit and flower production the next year as well so we'll see what next year brings. This is definitely an interesting issue.

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  3. An interesting post Marguerite, we expect our plants to perform for us during all sorts of conditions, during tough times they go into survival mode and sometimes if we don't pay attention we don't realise it. I hope weather conditions will be better for you next time around it's a shame you lost so much fruit, it can be very disappointing.

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    1. Karen, I guess I was really surprised because I always think of trees, especially ones as old as these, as being somewhat immune to drought.

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  4. It is good that you know but let's face it, there wasn't anything you could have done, unless you had the fields irrigated. Sorry Marguerite..sorry to see so many apples not achieve maturity, but it is as they say.."a composting opportunity".

    Wonder if you have an apple press? Can't recall you mentioning it.

    Good growing!

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    1. Brenda, you're absolutely right, there's no way we would have watered even had we known. I wish we had an apple press, on the long list of 'wants' but I'm not sure these apples would even be good for that considering they never did ripen.

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  5. I had apples dropping before I left in late August too, now I know why! In Ontario - NO APPLES! They bloomed too early, nipped in the bud by severe frosts a bit later. So sad.

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    1. Jane, Ontario had a really rough year with weather didn't it? I remember maritime growers talking about how our crop would make up for what was lost in Ontario as we just missed that frost but it seems now we have a different issue.

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  6. How frustrating for you but it's an excellent survival skill for the apple trees. Will you have any apples left to harvest this fall?

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    1. Tammy, at this point we're looking at zero harvest. What is left on the trees is so badly damaged it's virtually inedible. never thought I would see the day.

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  7. What a shame to lose so much fruit. I am glad you read up on it and figured it out. Hope next year is better.

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    1. Janet, I have my fingers crossed, apparently drought can affect flower production the following year so I have no idea what next year will bring.

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  8. How sad - and yet, how fascinating. That is actually an impressive survival strategy. Almost as impressive as your orchard containing over 20 trees!

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    1. It is really neat to see what a plant can do to survive. Despite the disappointment this was really interesting to learn. yup, it's a lot of trees to care for!

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  9. Such a destructive weather pattern - even here in my Zone 6 garden in SW Ohio. We had an arborist tell about 'limb drop' - siting the same reason - the heat and drought - hang in there - And let's hope next year is better.

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    1. Hi Claudia, thanks for visiting. I've never heard of limbs dropping off! but I guess when you see branches dying back it can be the same reasons. Learn something new every day.

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  10. We have several apple farms one street over. I noticed a sign on Marie Ferri's farm that reads, "Sorry closed. No apples this year." I feel so sorry for these farmers! The drought has been devastating for apples everywhere. I hope you are still able to salvage some of your apples Marguerite.

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    1. oh my goodness, that is horrible Jennifer. While we don't expect to salvage anything our apples aren't a monetary crop so it's not hurting us any. Usually we do everything we can to load them off on other people for free. I can't imagine losing everything when that is your source of income.

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  11. This was so interesting, Marguerite! I've noticed very few apples on our lone remaining apple tree this year, so it looks like I won't be baking much this fall. But in past years, when we had the two apple trees, I often noticed this phenomenon as well. I always wondered why some apples would fall before they ripened. It's kind of like the trees' own way of survival of the fittest.

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    1. Rose, I've had to learn a lot about fruit trees very quickly in the last couple years. I had never heard of fruit drop either. It's really quite interesting that they overproduce and then drop fruit but this year I learned something new again when I saw fruit dropping this late. The garden never ceases to amaze me.

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  12. We've had a little fruit drop too. Although we irrigate, our soils still are relatively poor in the orchard, so they can dry out quickly during a run of warm weather. As our apples are planted at the top of the slope, which tends to run drier than the bottom of the slope, they tend to jettison fruit sooner. I'm hoping to improve the moisture holding capacity of our soil more over the next few years to avoid this. That said, I hadn't thought to check the fruit circumference (other than the 'oh gee those look small this year' casual observation) to indicate water stress. Maybe I should spring for a pair of calipers!

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    1. Clare, I think you would have to have quite a bit of experience to judge an apple by its circumference. With all the different varieties and conditions each year there's a lot of factors affecting the size. I did find it fascinating though that some people would know their orchards so well they could judge the crop by the growth rate.

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  13. I didn't realize PEI had suffered drought this year. Maine escaped; although July was hot and dry, we had higher than average rainfall in May, June, and August. -Jean

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    1. Jean, we haven't had severe drought comparable to many other places so I guess we flew under the radar but some crops were affected. Early potatoes and hay are two I've heard about. Water springs as well were drying out. It's rather odd actually, had it been more severe I think more people would have taken notice and been forced to be more water conscious. As it was, nobody seemed to care which was really unfortunate.

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