The Great Tomato Experiment: Does Pruning Effect Fruit Quality?

[hippiestink]

Okay so for the BYC Gardening Thread I'm currently doing a Great Tomato Experiment. The experiment? Pruning vs. Non-Pruning.

The question is, does pruning tomatoes really significantly change the flavor and quality of the fruit? The current hypothesis of most experienced Garden Masters is that pruning bears better quality fruit while most gardeners in the thread don't notice a difference. So I'm going to find out once and for all which is better!

I am currently working with the following varieties. We live in the temperate Flanders region of Belgium, USDA growing zones 6-8; we get plenty of rainfall and relatively cool summers.
3 Indigo Rose (indeterminate)
3 Russian Black Sea Man (determinate)
3 Roma VF (determinate)

Of these, here is the list of pruned plants:
1 Indigo Rose
2 Russian BSMs
2 Roma VFs

Unpruned:
2 Indigo Roses
1 Russian BSM
1 Roma VF

They all are growing in the same zone, with the same amount of water and rainfall. All are watered every day to every other day. They get fed a homemade organic fertilizer once a week. The only changing variable is pruning. I pruned late after neglecting the plants through most of the season, as I didn't realize you could prune them, which meant that by the time I actually began, they were in bloom and beginning to fruit in some cases. The only thing I have done to the unpruned plants other than water and feeding is take off any yellow leaves or withered branches.

All are currently in flower or putting out first fruit. Three are fairly large, three are about medium, and three are kind of puny but have time to grow. This is being done in a rooftop garden in a large 1x1 meter tiered planter. I'm keeping relatively diligent watch and notes at this point, as I really haven't been this year and I want to do this experiment properly. Pruning took roughly three days to complete, so while we are technically on Day Four it is really more like Day One.

The unpruned IR plants have more immature fruit than all the BSM put together. The Romas are roughly in the middle with two half-developed tomatoes and a few small immature ones forming on the largest pruned plant. The BSM has only two half-grown fruits and one immature fruit on the pruned plants , with most blossoms still just flowers and not drying out yet.

The two unpruned BSM and Roma plants have only blossoms (and not many). All the IR plants are beginning to fruit, with the unpruned IR plants putting out more fruit than the pruned. I'll keep everyone updated daily on the experiment!

 

[lazy gardener]

Your results may also vary according to where plants are spaced in that growing bed. You've got some intensive planting going on there. In my experience, even in a traditionally planted garden, the plants at the outside of each row or bed grow bigger than the ones in the middle, as they don't have to compete so much for water, nutrients, space, and most importantly, light.

 

[oldhenlikesdogs]

Two types of branches on a tomato plant, the leaves for energy, and the production shoot, my name for it, now I remove bottom leaves so they are not touching the ground to avoid the blight than mulch with grass clippings, I prune out as much as the downward growing leaves as necessary for air circulation and to find the fruit easier, now here's your debate, prune out some of the fruiting branches gives you less tomatoes, but possibly larger, doesn't affect the flavor, I leave all mine because I like as many tomatoes as possible. Flavor is determined by variety, and the weather, hot years means sweeter tomatoes, cooler years makes for tasteless tomatoes, and blight will affect the flavor as well as it alters the ripening process, so pick the right variety and hope for hot weather and even rain.

 

[shortgrass]

I experiment with LST, low stress training...

It's more than just pruning, but TRAINING stems to go where they can utilize light and space...ie, I don't actually "prune", but twist the main growing stalk until I hear a slight 'snap', not breaking the stem, but just the phylum. Then bend the stem down to ground level and tie it down... This takes the main growing shoot down and lets the plant send growth hormones to the lower branches, where they can catch up to the top, and by the time the top is vertical again, all lower branches are even with the main shoot, essentially making 6 growing tops instead of just one.

The best benefit to it is not just increasing yield, but decreasing the likelihood of snapping a bush variety from being overweight at the top, and vining ones from getting 12'long. It " compacts" the whole plant...

Snapping the phylum increases water intake and thickens the stalk so it can hold the weight of the massive beefsteaks and big boys I prefer... Our winds snap them at every chance, so I need all the plants to stay close to the ground, bushy

* I should stress that this is done when they're seedlings, before setting flowers. Stem is still very pliable and easy it manipulate

 

[MeatTheFlockers]

Oldhenlikesdogs pretty much nailed it. The main reason for pruning is to increase airflow and to prevent contamination of soil-born pathogens from splashing onto your plants and leaves. As you can see in the above picture i prune heavily and eliminate most of the long vines that touch the ground. This plant also happens to be grown on just a single stem. No problem with production, and way too many variables with not enough controls to be conclusive either way. Some plants I let sprawl and I dont see any increase in production that way either.

Indeterminates can be pruned, and controlled that way. The will continue to grow and continually blossoom until killed by frost. Pruning can keep the size manageable and allows you to limit the number of growth shoots.

Determinates and dwarf varites should not. Their branches usually end with a growth node and pruning actually eliminates the chance of fruit on those growth nodes. Determanites have a shorter life cycle and tend to set fruit all at once. Not pruning maximazes yeild on determinates.

Which to grow should be determined by your location, growing season, and intended use. Again way to many variables but a fun comparison never the less. Good luck to you.

 

[hippiestink]

These are current photos of the flowers/fruits of each and every plant. They will be labeled for the purposes of this experiment.



The planter and plants involved in the experiment. (pardon my mess)



Small pruned Indigo Rose plant, already fruiting.



Small unpruned Russian Black Sea Man, fruiting.



Small unpruned Roma VF, flowering.



Medium unpruned IR, flowering.



Medium pruned RBSM, flowers and fruit 1



Medium pruned RBSM, flowers and fruit 2



Medium pruned Roma VF, flowering.



Large pruned RBSM, fruiting.



Large unpruned IR, fruiting.



Large pruned Roma VF, fruiting 1



Large pruned Roma VF, fruiting 2

 

[Bugseye]

Oh, goody! Glad you posted pictures.

 

[hippiestink]

Day two of experiment. Sky is very overcast and weather is calling for 95% chance of rain. We will see what this means for the experiment later.

The large pruned Roma VF has one branch that is browning, probably accidentally broke it or something when I was doing the pruning. None of the plants are showing shock, and several are fruiting at a steady rate.

 

[hennible]

Hi Stink
I'm subscribing!

 

[HeritageGoose13]

This is interesting. Some farms swear by it and others think its a terrible idea. I did it for a while and my tomatoes seemed to be producing less so I stopped.