Cause of Fruit Drop

[aclum]

Hi,

If you've seen my recent thread in the photo section (Anne's garden 6-17-16), you know that I've been pruning my plants heavily and repositioning the vines with trellis clips on drop lines so that they drape horizontally.

As I've repositioned the vines, I've had a few green fruits just drop off the vine and I was wondering what might be causing this. It's not been many - actually just 3 or 4 out of 125 green fruit at this point. Could it be that the plants are overloaded with fruit (esp. in proportion to the foliage) and are sort of "self-culling" or something else??? The plants are really very healthy otherwise (again "at this point" ) with some of the nicest looking fruit I've ever had - only 1 fruit with BER, virtually no cracks and only a couple of fruit with catfacing. (Not bragging - just trying to help with a diagnosis ).

Any ideas? I don't want all my green fruit to start dropping off!!

Thanks,
Anne

[My Foot Smells]

I have some drop if I vigorously fool around with the plant. When tomatoes form in bunches, often some are not strongly secured to the stem and flop off. Just my opine, but have had it happen when picking or pruning.

Fried green tomatoes?

[Shapshftr]

Originally Posted by aclum

Hi,

If you've seen my recent thread in the photo section (Anne's garden 6-17-16), you know that I've been pruning my plants heavily and repositioning the vines with trellis clips on drop lines so that they drape horizontally.

As I've repositioned the vines, I've had a few green fruits just drop off the vine and I was wondering what might be causing this. It's not been many - actually just 3 or 4 out of 125 green fruit at this point. Could it be that the plants are overloaded with fruit (esp. in proportion to the foliage) and are sort of "self-culling" or something else??? The plants are really very healthy otherwise (again "at this point" ) with some of the nicest looking fruit I've ever had - only 1 fruit with BER, virtually no cracks and only a couple of fruit with catfacing. (Not bragging - just trying to help with a diagnosis ).

Any ideas? I don't want all my green fruit to start dropping off!!

Thanks,
Anne

Physiological stress is the reason for both catfacing and fruit drop. Catfacing is more common in beefsteak varieties. You must have had some low temps overnight while the plants were blossoming and setting fruit.

Fruit drop. Tomato fruit set and development is considerably affected by overnight temperatures. When temperatures are over 75 F or under 55 F at nighttime, fruit has difficulty setting and maturing. Next time, if overnight temperatures are forecast to be cold, consider using a space heater in the greenhouse. Fruit may also not set when plants are exposed to too much shade or are under-watered. In addition, check the fertilizer balance. Nitrogen (the first number in a fertilizer's three-number designation) promotes vegetative growth. Once plants flower and begin to set fruit, they need more phosphorus and potassium in order for tomatoes to be healthy and mature.

[Gardeneer]

I also think that they drop due to handling /disturbance.

Gardeneer

[Allisa]

Originally Posted by aclum

Hi,

If you've seen my recent thread in the photo section (Anne's garden 6-17-16), you know that I've been pruning my plants heavily and repositioning the vines with trellis clips on drop lines so that they drape horizontally.

As I've repositioned the vines, I've had a few green fruits just drop off the vine and I was wondering what might be causing this. It's not been many - actually just 3 or 4 out of 125 green fruit at this point. Could it be that the plants are overloaded with fruit (esp. in proportion to the foliage) and are sort of "self-culling" or something else??? The plants are really very healthy otherwise (again "at this point" ) with some of the nicest looking fruit I've ever had - only 1 fruit with BER, virtually no cracks and only a couple of fruit with catfacing. (Not bragging - just trying to help with a diagnosis ).

Any ideas? I don't want all my green fruit to start dropping off!!

Thanks,
Anne

I was told not to prune more than 2-3 leaves at the time per 1 week, it could stress the plant. Also, when I prune leaves I leave two small leaves on the leave itself, it gives some time for the plant to adjust. Temps could play a role too, as well as potash or phosphate deficiency, but usually if there is some deficiency you'd be able to see on the leaves.

[NarnianGarden]

I remember a fascinating conversation here at T ville three years ago, about this topic. It also came up that some little green nobs just seem to sit there for a long time: they don't seem to do anything, but they aren't dropped off either. There seems to be no logic whatsoever when and which fertilized flower begins to form a fruit...
If the plant is otherwise healthy, growing and producing flowers, there is no reason why the fruits don't grow. Sometimes they begin to grow after weeks and weeks of inactivity...
Being as impatient as I am, I would love to see fruit-setting right away... ! But nature has its own mind.

[aclum]

Hi,

Thanks for all the input. I think now that the fruit drop must have been due to my vigorous pruning and manhandling of some of the vines in order to get them to drape horizontally when they had been quite happy growing vertically. Since the plants have been "disciplined" , they've been very well behaved with virtually no fruit drop. Some of the vines are now so horizontal that they're almost a sprawl with the fruit resting on the mulch - so they really can't fall off the vine even if they wanted to .

Lots of fruit ripening now, but the plants are looking a bit worse for wear due to the 100+ heat spell we're going through. It's supposed to be 106 here today .

Anne

[BigVanVader]

Sungold drop fruit pretty much every time I touch them. I told my wife they act like a kid caught with his hand in the cookie jar.

[Shapshftr]

Originally Posted by Gardeneer

I also think that they drop due to handling /disturbance.

Gardeneer

Well mine never do. I have to fight to pull them off without ripping the truss all the way down the stem.

[efisakov]

Some tomato varieties drop fruit more than others do. Eva Purple Ball is one of them. I just touch the fruit and it is off. Which variety did that for you?

[b54red]

If you are having the high temps you mentioned then my best guess would be a slight deficiency in moisture. When it is really hot the plants need more moisture in the ground than normal or fruit drop and blossom drop will occur. I have found that just one day of too dry conditions with high temps will cause some loss and sometimes quite a bit depending on how dry or how hot. It is going to happen sometimes but I doubt the pruning and handling had too much to do with it unless accompanied by lack of moisture. I always find it nice to water them well before pruning or at least right afterwards especially with heavy pruning during hot dry weather.

Sounds like you are using the same method of plant support that I am. Are you using the drop line method and moving them all in one direction and lowering them as they get taller? I love this method but sometimes lose a few lying on the mulch ripening to slugs which are more than plentiful in my garden despite lots of slug bait applications.
I have found that it is a lot less work with only a single stem and plant fairly close for shade; but it does require frequent maintenance and pruning. I find it much less work than any other method of plant support that I have tried over 40 years of growing tomatoes. If you are using this method I will give you a tip I finally figured out that if you start the drop lines already at the angle you will be laying them as they grow then it is far easier to make that first drop since the plants are already trained in that direction.

Bill

[Tormato]

In my garden, gravity is the cause of fruit drop.

What causes it to first release from the stem, I don't know.

Dr. Lve Apple

[Allisa]

Originally Posted by NarnianGarden

I remember a fascinating conversation here at T ville three years ago, about this topic. It also came up that some little green nobs just seem to sit there for a long time: they don't seem to do anything, but they aren't dropped off either. There seems to be no logic whatsoever when and which fertilized flower begins to form a fruit...
If the plant is otherwise healthy, growing and producing flowers, there is no reason why the fruits don't grow. Sometimes they begin to grow after weeks and weeks of inactivity...
Being as impatient as I am, I would love to see fruit-setting right away... ! But nature has its own mind.

I had some varieties that would start to grow fruits when the weather gets cooler again, about 2.5 month later. So, last year I tried to trick them, I took off the top of the plant in July and almost all green nobs started to grow. Some of them were good size, others (especially on the first trusses) were very small, not worth to keep them. My guest is that when pollination happened there was not enough mature pollen to pollinate, that's why first grow good pollinated fruits and then after they are gone, more weak nobs start to grow. I might be wrong, it could be my imagination of the reason)))

[aclum]

Hi Again,

And thanks again for all the replies - some were fairly amusing .

Ella - There were only a few fruit that fell off the vine (and none since my original post). As I recall, it was one Wes and 2 Goose Creek and maybe one or two others I don't recall . I know about EPB just dropping off the vine of their own accord when ripe. The ones I had drop were all at or near full size but still green and fell off when I was working near the vines. So I'm pretty convinced it was my rough handling of the plants that caused the fruit to drop.


Bill - I'm kind of doing the same sort of trellising as you are, but not quite. We both end up with the vines being draped nearly horizontal/parallel to the ground, but, as I understand it, you reposition the drop lines with tomatoes attached and I leave the drop lines in place and reposition the actual vines on new drop lines. I unclip the vine from where it is, move it over one of two drop lines, and then reattach the vine to the new drop line. By doing it this way, I don't have to access the drop line's attachment point at the top of the trellis and I don't have to struggle with the weight of the whole vine at once. Lots of photos and maybe a better description over in the photo forum in a thread called "Anne's Garden 6-17-16."

My paths are all covered with heavy landscape fabric (with cardboard underneath in some places) and the beds are covered with reflective silver mulch so I haven't had any problems with snails or slugs, etc. damaging the fruit resting on the mulch (knock on wood). The original soil beneath the beds has a high percentage clay and what with the silver mulch, the raised beds seem to retain moisture pretty well. I've been hand watering about once a week with TTF and Azomite at a rate of about 1TB each/gal water. I just water until it stops soaking into the soil at the base of the plant and do about 7 plants/gallon (whatever that works out to be). With the hot weather, I've been watering a bit more using the soaker hose beneath the mulch (in addition to the hand watering).

Anyway, thanks for all the input - I think the green fruit dropping drama is probably over for the time being .

On other matters.....not a permanent solution, but here's a photo of a quick temporary sunshade for a cluster of almost naked tomatoes made from a zucchini leaf I needed to trim (it was shading a pepper seedling).

Anne

[NarnianGarden]

That is so creative of you - what a great way to recycle your gardening products!