A question about Determinate vs Indeterminate

[Worth1]

Originally Posted by xellos99

You would think people in Texas would have 12 ft monster plants with all the sun but im finding out from this website that you have your own set of problems with more extreme weather swings, heat and pests I never heard of.

I have grown 16 foot plants but few tomatoes due to blossom drop from heat.
With these recent wild weather swings it is really cramping my style.
I already have a mental list of ones that do good here and will grow them from now on.

[maxjohnson]

Can I get some opinion on this Orange Roussollini, sold by MIgardener's (I know he gets a bit of criticism from around here, but nevermind that). There seems to be two trusses for every one leaf branch, I'm assuming it's some kind of determinate characteristic. It's a short and bulky plant, and blossoming like gangbusters.

The white lines are the trusses and green are the leaves.

[clkeiper]

max, that appears to be a determinate growth pattern to me from what I can see. leaf,leaf , truss, leaf leaf truss.

[bower]

Yup, if there are three leaves in between trusses, it is almost certainly indeterminate (discounting some segregating crosses). If there are two leaves between trusses, it is certainly determinate.

[dfollett]

Originally Posted by bower

The google description is vague to me, more about how determinates are used or grown.

It only makes sense to me to use the genetic description. The sp gene produces a terminal bud on mainstem and side shoots, therefore you get plants of short stature.
This never causes the plant not to produce new stems when it's finished fruiting, in my experience. The only reason it would stop is no food, no water, end of season or killed by some other thing. Prune em back, feed em, and they will keep on. This is great for micros which can be grown all year round indoors anyway. You should be able to just keep them going. (to a point, depending on how rootbound the pot is, maybe a root pruning? would renew as well).



A second characteristic associated with determinates is a reduced number of leaves between clusters. So instead of three between as in indeterminates, you may have varying patterns of two or one leaf only in between flowers. However, in growing out determinate X indeterminate crosses, I've seen lots of cases where the terminal bud was associated with the 3-3-3-... leaf pattern, and so I'm not certain if they may be under separate genetic control. Put it this way, the terminal bud sp/sp condition is stable long before the leaf pattern.


The term "semi-determinate" is applied (in scientific work) to plants that have terminal bud (sp/sp) and have six or more clusters on the main stem. So they are taller than the average determinate but will "self prune" eventually. The larger plants have more leaf area/resources for suckering freely and producing continually, is my take on the production question.


Breeders of determinates for field production have deliberately looked for plants that ripen their crop all at once for convenience of harvest. In practice, the determinates I've grown actually have ripened over a window of about two weeks. I have seen determinates that didn't ripen any fruit until they had finished flowering and setting. Don't know what that is governed by genetically, but it's not unusual for ripening to be delayed (in any tomato) by a very heavy fruit load. A normal load may be "heavy" for a small determinate with not too much leaf space to work.

Thank you. That's knowledge that is very useful.