A question about Determinate vs Indeterminate
 

I have a question regarding ‘determinate’ vs ‘indeterminate’. I always thought I understood the difference – but a couple of plants I’m growing make me question that understanding. Looking it up online didn’t clarify anything – but I didn’t look beyond a simple Google search. That confirmed what I’ve always thought but contradicts what I’m seeing.

According to Google:

• “Determinate tomato plants grow only to a set, specific size and produce a single harvest of tomatoes. These plants stop growing after the top bud has set fruit.”
• “Indeterminate varieties continue to grow and produce tomatoes all along the stems throughout the growing season.”

Two different micros I’m working with seem to be ‘indeterminate determinates’ (for lack of a better way to say it). Will determinate plants put out a second crop? They both did the same thing.

• They grew to a specific size and set fruit on blossoms at the end of the main stem – like determinates.
• They them ripened those fruits over a relatively short period of time.
• About the time the final fruits ripened, two side-shoots started growing.
• Those side shoots have now set fruit at the end of their stems – with no additional growth showing.

First photo was about March – the plant was 6” tall – Second photo was April 1 – Third photo was today – the plant is 13” tall. Nothing has ripened since those two that show on the second photo.

So….are these plants determinates (I think so) or are they indeterminate?

Is a determinate really a plant that’s main stem terminates with blossoms that ripen together and that may or may not put out additional stems that do the same thing? And an indeterminate is a plant that’s main stem (and side stems) don’t end with terminal blossoms and therefore keep growing? If that is the case, the online definitions I found – mostly from seed vendors – are incorrect.

An interesting sidelight - I have 20 daughter plants that are blossoming from the first few fruits to ripen in early March. Is that type of growth pattern very heritable?

Semi determinate.:)

[QUOTE=Worth1;735805]Semi determinate.:)[/QUOTE]

Thanks.....

Unfortunately few are using the correct terminology to label a variety. One of our breeders, possibly of your micros, defined a determinate as growing to a defined (short) height AND setting a terminal growth bud at each node if I remember correctly. Someone with expertise is sure to chime in soon with the correct description.


- Lisa

Bradley is another semi determinate. Growing it here in this part of Texas - you would think of it as an Indeterminate with Determinate production - over and over again. It is a delicious tomato with a very short shelf life.

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 :D 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. :)

determinates have a flower bud every 2nd node. leaf leaf flower. indeterminates have a flower every 3rd node. leaf leaf leaf flower.
I grew a pink determinate a couple years ago in my high tunnel. I assumed once it was done I could pull it out and plant something else of which was a pipe dream as time for projects like that is nonexistent.. as soon as the tomatoes were done it started growing again and made an even nicer crop the second time.

I mostly grow indeterminates, but did grow a couple of determinates along the way, and they seemed to produce throughout the summer......maybe not as much as indeterminates, but they still kept producing.

And then there are the semi determinate dwarfs.:)

[QUOTE=Worth1;735848]And then there are the semi determinate dwarfs.:)[/QUOTE]
The number of recessives in determinate, micro, dwarf is enough to boggle the mind.:? :dizzy: Only lucky that dwarf is detectable early, as the sheer number of plants you would need to find that growth habit.... :panic::twisted: Talk about overrun with tomatoes...

We had a talk here about 3 years or so ago about the distance from the roots to top of plant that stopped the growth of these type plants.
There is a hormone or something that takes place to stop growth.

I agree your plants are determinate Dan.
I think the health of the plant and the care its receiving are big factors.
If it was in the elements, in soil, exposed to disease it may not have had a chance to keep growing.
I also think in my case that light is playing a big role. All of my micros are still growing strong, reblooming and setting fruit better than before now they are out in the greenhouse. I expect them to last the summer or until I get tired of looking after them... I too thought they would be done by now so I could use the space for other things but they keep going and the look really great.
These plants were planted in October, were grown in the house all winter where they were able to set a smallish crop.
As to my numbers as an example, we started out with right around 300 seedlings from 4 separate crosses. , quickly able to cull that to about 90 dwarfs then again in a couple of weeks to about 70.
If the smallest. Between two of us we grew these over winter culling as we went those that grew too big, those that tasted too sour or watery and the final group of 8 selections are now growing at F3 so yes, we needed to start with quite a few seedlings to find 8 with potential.

I've seen Rutgers described as Determinate, Indeterminate, and Semi-Determinate. Imo, it's indeterminate. Have grown it several times, and for me, it fruited all summer to frost.

The weather changes here are going to force me into growing just determinates from now on.
I dont have time or space for a bunch of plants and want more tomatoes than I am getting.

[QUOTE=Worth1;735884]The weather changes here are going to force me into growing just determinates from now on.
I dont have time or space for a bunch of plants and want more tomatoes than I am getting.[/QUOTE]

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.