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Deer Park, WI

Whether ya like it or not, im gonna conintue babbling more of this source vs sink info that im stumbling across. I think its fascinating stuff, and has real applicable factors to our sport. So here's what else i dug up:

"The supply of assimilate to major sinks such as developing fruits becomes more and more localised with time" So what the hell does that mean. Well, if i understand correctly, a particular sink (big punkin)will become more dependent on particular sources. Rather than drawing a little bit of juice from everywhere, its depending on a whole lotta juice from a few places. Ok, fine and dandy, but tell how can we make this grow us bigger punkins? Well, here's the answer-

"Nutrient supply from sources preferentially allocates to the closest sink" Translation: Sources are kind of lazy, they prefer to dump their loads at the closest sink.

So, if you look analytically at the above, and apply it to our real world situation, you see once again the importance of proper pruning. Those massive 15' secondaries coming right off the stump are definatley pumping their juice to the roots. Pruning the vine tips and extra flowers is going to promote root growth.

12/1/2003 5:00:41 PM

Deer Park, WI

The mid-plant secondaries are feeding your huge pumpkin. This is where pruning becomes hella-important. Many people prune the secondary vines around their fruit. I say "whoa horsey". Not always the best idea. I have always waited to clip secondaries by the fruit until they become a significant threat to the health of the fruit. If the tip of those vines is pruned, and no tertiaries are present, then all the juices that vine is producing goes straight into that fruit. Remember the importance of proximity when it comes to photosynthate allocation. The secondaries closest to the fruit are the most important!!!

Finally, the vines out towards the far end of the plant are most likely fueling vegetative growth of the plant. The keen grower terminates all tips by mid-august, therefore switching this allocation from vines and leaves to the closest available sink...the pumpkin.

12/1/2003 5:00:55 PM

Indiana

I luv you Joe!

Tom ;-)

12/1/2003 6:09:12 PM

Nova Scotia

joze i think your stuff is great so keep it coming. so if sources dump into the nearest sink then would it stand to reason that the pumpkin would do better in the middle of all the sinks or slightly nearer to the greatest sink the stump?

12/1/2003 6:57:29 PM

Garden State Pumpkins

Great stuff Joze you keep sourcing I'll keep sinking!!

12/1/2003 7:11:57 PM

[email protected]

And here I thought Tom had eyes for Brigette. I'm confused.

So a set that is *too far* from the stump area could be a detriment to optimum growth? Then the earliest set in July (or late June) might be destined for succes not so much because it is *early*, but perhaps because of it's proximity to a source in addition to the extra time it has to grow.

The question then begs; how much additional vine after the fruit is considered souce? And when does more vine after the fruit become sink? Do we measure in feet or leaves?

Steve

12/1/2003 7:14:33 PM

Menomonie, WI ([email protected])

Are we Gardening or Plumbing?...LOL

12/1/2003 7:15:49 PM

Mulino, Oregon

Joe, I believe your theory regarding mid secondaries is right on, but... Plants also have a built in survival trait/quality such that when the primary and secondary terminal buds are eliminated (ie termination), the plant goes into 'survival' mode, which means much of the energy goes into either a) tertiary development (we've all seen it, especially if we missed a few during pruning) and b) fruit development (Preserve the species!!!) Steve Daletas's WR pumpkin was out at about 20-25' from the stump. His main stump rotted off in early September and was still gaining 20 lbs/day off his secondaries. This moves the 'sink' quite a ways out from the 'source'. Which might explain the faster late season growth rate for the fruits that are kept further out from the stem. Hence the extreme importance of the roots and early season plant growth in fruit development.

12/1/2003 8:04:10 PM

Nova Scotia

i read one post befor by a heavey hitter (i forget who) that said he beleived like grape vines that there is an optimal length to side vines just befor they start to become a waste of energy and he beleived it to be 14' each way. (right now i can only go 10' each way) but i also beleive that each plant has it's own prefrences. specific prunning for one plant will not work for another.

12/1/2003 10:01:06 PM

Knopp, Germany

I think that the question of how much plant growth is optimal as source and when (how long in feet) do the secondaries go from being source to sink, are key. I know that a big pumpkin can be grown in 400 sq ft, that has been proven, but was it an accident, luck or intended? Did they use the ideas of source and sink in the pruning of the plant? Could a secondary main, grown away from the primary main, have its own potential for source and sink that doesn't effect the primary? Did anyone measure the length of Bruce W's secondaries? According to the AGGC his fruit was pollinated at 11.5 feet out and the plant had over 900 sq ft. I wonder how long his main was after the fruit? Great topic Joe, I see the potential for another article for you in this.

12/2/2003 3:54:18 AM

Deer Park, WI

Tom- you two-timing dirt bag. Shame on you.

Jim- I have another suggestion for Steve's fantastic growth rate in september. Keep in mind that roots are indirect sources, not direct. All water flows from the roots to the leaves, from the leaves to the pumpkin. No water flows directly from roots to pumpkin. The primary sources are leaves. Having a pumpkin set out at 20-25' suggests that the leaf material out there is probably very healthy, just hitting its peak. Therefore, the pumpkin was getting a strong supply of juices from these powerful sources. Hence the great late season growth.

Mr. T- Im leaning towards a pumpkin set between 10'-13', as has been suggested all along, if your plant size is 500-800sq ft. The larger a plant is, the further you can set a fruit on the vine, as evidenced by the Daletas monster.

Steve- you pose some very intuitive questions- I agree that an early set (late june early July) is optimal, so long as you have at least 10' of vine between fruit and stump, simply because it gives you an extra week or two of growth. If you are a frost-dodger such as myself, this is critical.

12/2/2003 9:08:03 AM

Deer Park, WI

To answer your second question, All leaves will become a source when they mature. Infant leaves begin as sinks, but develop into sources over time. I dont think we can measure in feet or leaves on this issue, it would be very hard to determine how much sq footage in front of the pumpkin is optimal. HOWEVER...if there are absolutely no tertiaries, no flowers, and the tips are nipped, that photosynthate HAS TO GO somewhere. and where else but the pumpkin.

Like Jim said, ever notice how fast those sneaky tertiaries you missed will grow when you think your plant is pruned well? Its seems like you can watch those suckers get longer. All that energy in the plant is very powerful, especially when its focused on just a couple sinks.

Shannon..since you are competetion for me, im talking plumbing here. This whole thread has absolutely nothing to do with pumpkins. This will teach you how to unclog a drain in one quick step. enjoy.

12/2/2003 9:08:11 AM

[email protected]

http://www.co2science.org/subject/s/summaries/sourcesink.htm

Perhaps this is fodder for a new thread. co2 enrichment & it's relationship to sink/source data.

This is a cool thread.

12/2/2003 9:25:01 AM

ipswich, ma usa

I had the opportunity to visit Bruce Whittiers patch over the summer along with Geoffery pearce's "Boss Hog" (look at what he brought to Topsfield) and a few other NH growers patches. They did not terminate their main vines as of the time I was there in late July. I heard from future patch visitors that they did not terminate their main vines at all during the growing season. Just thought I would throw that in.

John (5150)

12/2/2003 9:51:13 AM

Utah

nice thread joe---
keep them coming.
---gordon

12/2/2003 10:33:43 AM

[email protected]

Maybe the root/fruit relationship is causing confusion. As Joe says, roots move water (& soil nutrients in solution) *only* to leaves through the ZYLEM (a one way street). These are the big tubes we see when viewing a cross-cut stem. This material arrives at the leaves & becomes the fuel for *Source Production* or *The Food Factory* we hear folks talking about. Photosynthesis combines with sunlight, water, & critical nutrients into the Source (Joe - balast me if I'm confusing this). Transpiration fuels this *push* (aka osmotic pressure). This is why critical soil moisture levels must be properly managed.

The source material heads to Sinks via the PHLOEM (a 2 way street) by way of *Translocation*. The Phloem is the smaller yet more numerous vascular tubes we see in the cross-cut vine. Translocation is what we're after. There are many influences on translocation. Sink/Source (for the purpose of our discussion) is the process of directing translocation where we want it to go. But not nesacarily the regulation of the rate of translocation. Just the path. The plant could be left alone to do as it is genetically progamed. But then we wouldn't be Giant Pumpkin growers. So we want to alter the course to our advantage. So we *direct* via pruning.

Where I get lost here is the critical influence that critical plant growth hormones influence the sink/source relationship & the effect we have by pruning.

That and the proximity of the fruit relative the rest of the plant.

Case in point:
In c. pepo, radioactive tracer dyes have tracked sucrose (sap) movement (via translocation) through the phloem at rates of 100cm per hour. But for the life of me I can't find referance to how *far* that sucrose solution traveled.

Did I make my question clear or did I just muddy up the water even worse?

Steve

12/2/2003 10:53:56 AM

Garden State Pumpkins

What a great thread..Still "sinking" about the questions but have a better understanding of how important keeping the leaves healthy and why...as long as that cation exchange stuff doesn't sneak in I think I'm following so far!

12/2/2003 12:58:26 PM

Stouffville

i think better seeds make the pumpkin a bigger sink but how this is accomplished i don't know

12/2/2003 5:25:23 PM

[email protected]

Boy I've really got to proof read posts. Darn phone ringing off the hook with the snow.....ugh!

12/2/2003 5:47:19 PM

Calif

I think sinks and sources are ever changing at different life cycles of the plant. Roots come and go leaves come and go. And the plant compensates to get what it needs to enhance its fruit and existence. you would think the tap root and tertiary at the pumpkin stem would be best . Yet those are most the time cleared . And the weights keep climbing......so it appears that the vigor to replace and compensate are the genetic traits needed........knowing where to focus sure would be sweet......or is it a whole unit that should be concentrated on? Also alot of growers keep the main growing some let fruit keep popping to keep the plant in a unfinished reproductive mode-----with the feeling if the plant feels its mission is complete --calls it a season.----MB

12/2/2003 5:48:29 PM

Stouffville

Well from my experience, plants are huge sources, what limits fruit size is the size of the sink an individual pumpkin has....hmmm just had a new thought I've had 700lbers hit 27lbs a day for a short period (~6 days) and then quit...so that sink dried up quick cause the source was pretty healthy and hadn't changed. so basically final size of a fruit depends on both the 'size' of a fruit sink (ie max growth rate reached) and the duration that the sink can be maintained of course assuming you have a healthy plant >400ft^2 in decent soil with adequate moisture and warm weather.

A large fruit sink that lasts for as long as possible is what we're looking for and this is a mysterious characteristic linked to genetics as far as i understand it

12/2/2003 6:21:37 PM

Menomonie, WI ([email protected])

Joe if I understand this right. A sink is what April is to the check book, and I am the source. By reducing this distance and how things consumed. My pumpkin should grow bigger. :)

12/2/2003 7:23:00 PM

Deer Park, WI

Nice explanation Steve...it is all right on. Except for your spelling of Xylem, but i wont be picky :)

You bring up the next major issue in this dicusssion, the influence of PGRs on sources and sinks. Without a doubt, they do play a role. However, what that role is has yet to be discovered (at least by myself) and how to properly use PGRs to our advantage is even further out of our grasp. I'll dig into that today and see what i can find.

Regarding sink strength, It looks like the most accepted determinent is sink size and sink activity. This is a fairly ambiguous definition, and doesnt provid us much useful information. Basically, the strenght of a sink is dependent on the size of the sink, combined with how active they sink is. Activity refers to how quickly sucrose being imported is metabolized to carbohydrates. And size is fairly obvious. Since we dont have control over either of these factors (yet), it becomes very hard to increase the sink strength of a particular pumpkin. Thus, once again, all we can do is manipulate other sinks on the plant.

12/3/2003 9:09:05 AM

Utah

joe good post-
yes- there are factors that we don't have control over. one thing i think needs to be stated is the fact that while we try to impose our theorys and logic on these plants, I believe it is pretty much impossible to do so because the key sink in the equation, the fruit, is a female and as history and experience tells us, for a certian percentage of the population, theory and logic do not apply. They just do what ever they want when ever they want to do it, logical or not! Maybe we should try to shift our ideas to more of a communication and emotional based approach, keep an open dialoge up and explore daily feelings. I think this approach has already been proven out in the fact that a small percentage of the total growers are females yet their success is higher than average by a long way, as two recent world records have shown. They start with a common back ground of both being female and thus have a bond and a connection that male grower, even with hard work and effort will never never be able to come close to acheiving. We are just wired differently. Our Y chromosome leaves us deficent.

12/3/2003 9:39:24 AM

Indiana

So glt your saying that we should cuddle with out pumpkins??
Steve

12/3/2003 11:39:25 AM

[email protected]

Now let's not get all soft here. I find it's much easier to open a nice California Chardonnay than try to think with the "other" side of the brain. Perhaps candles & soft music in the patch?

12/3/2003 11:48:12 AM

Itzetown City

California Chardonnay in my opinion has 12,5 vol%, does that have any matter to the seeds if you feeding the pumpkin with that stuff? On the other hand, some times alcohol make thick and heavy and you´ll have the happiest pumpkins at the competation. LOL

12/3/2003 12:23:37 PM

Knopp, Germany

wow Gordon, you never fail to amaze me.....of course, amazing me is a short trip...lol

12/3/2003 12:46:40 PM

Utah

i was just wondering if how many people were actually reading this thread. ever wonder if some people only read threads with titles they like on message boards they like or only read threads that are 3-4 lines or shorter ? so if we have more than one fruit in our patch does that make us polygamist ? just a random thought i just had. but please don't let my previous post distact anymore from the good thread that was going.

12/3/2003 2:40:13 PM

[email protected]

So we've arrived at a crossroads. We have determined that we need to modify (to our advantage) the translocation of sap by means of the sink/source relationship by means of vine management.

How: Remove all extraneous flowers, vines, & other meristematic points that may be sink.

Why: To concentrate sap flow towards our desired sink (the pumpkin).

When: The plant has sufficient "source" material to reach a desired growth goal but before the fruit has reached the stage where our influence is no longer maximized.

When seems to be the question. All leaves will become source in time. Slime plugs (P-Proteins) block seive plates causing young leaves to cease being sinks (mature) at a (genetically determined?) given growth stage (how? presumed hormonal influence). The likely signal being seeds & the production of specific GA hormones.

It is at this stage that the phloem takes on a new role as the path of translocation becomes altered away from leaves (as sinks) & towards the fruit (as sink) & leaves are thus established sources. Cucurbits also enjoy the often debated "plasmatic filaments" which likely play a role in additional phloem transport pathway.

We can alter the role of leaf (as sink) by several means (aluminum foil, GA inhibitors (don't laugh- it might work!), pruning, or other environmental stress. But we must first establish that the source is of sufficient capacity to meet the goal. And this brings us back to the timing of vine termination with respect to the development stage of the fruit. How many days old should the fruit be when we start to remove all other sinks on the plant?

brb

12/3/2003 11:06:15 PM

[email protected]

It would stand to reason that the more healthy (functional) leaf area we have at the time of vine termination, the larger the source will be. But this requires time to produce.

Is it better to establish an all source plant early with respect to fruit development stage? Even if the source is smaller than previously thought desirable?

Should we seek to modify the phloem transport of source material (soluble carbohydrates) to specifally coincide with a fruit development stage?

Should we intervene the natural hormonal processes with an "artificial signal"?

Would we chose to disregard seed formation over soluble carbohydrate transport & storeage for the sake of weight gain? Does stored carbohydrate even weigh more than seeds? Has anyone established their individual bulk densities?

De we seek to alter the plants capability to convert sugars to carbs? What of the theory that amino acid blocking might positively influence carbohydrate conversion? (I don't know that this has ever been successfuly implemented in the field so perhaps we should leave it alone)

Many questions. Only several options. I plan to visit with a strong industry ally in the days ahead. More heads are better.

Steve

12/3/2003 11:21:45 PM

Syracuse, NY

wow! neat stuff, but it'll take me two days to read it all!
maybe i'll take Friday off......

12/4/2003 5:42:53 AM

Deer Park, WI

An examination of literature yesterday provided some insight into the hormonal regulation of fruit growth. There's no question that specific PGR's influence the growth rate by signaling cell division and expansion during the growth cycle. These signals come from the seeds, but, and this is a big but, seeds do not produce the signals. Therefore, the seeds are acting as the actual sinks (magnets?) that draw the hormones into the fruit. So, now we have evidence that seeds, and more specifically pollination and fertilization, do play a significant role in fruit growth. For a novice, it has been suffice to know that this year's pollination will have no effect on the fruit, only the seeds inside. But this newfound evidence suggests the opposite. Apparently, a greater number of seeds (pollinated and fertilized) will lead to greater sink strength, when it comes to PGR importation. Increased PGR concentration in the fruit signals higher rates of cell division and expansion.

Now, it seems topical application of a specific PGR wont do the job. What we need to do is get specific quantities of PGR to the inside of a developing fruit. Possibly thru hypodermic injection.

Bring on the steroid jokes. Just like in people, you cant rub "the juice" on, ya gotta inject it to the right spot.

ahhhh we have a long ways to go here.

12/4/2003 9:08:26 AM

[email protected]

Joe, It seems we're still also pondering the when. Is seed formation (the 3 stages or phases) a short term process that occurrs within some hours or days of pollination? Or is it a period of several weeks?

We know that the different phases involve different hormones. We know those same hormones are developed & inluence other growth aspects of plant growth.

The last thing we want to do is time or place a hormone in a way that is counter-productive to the goal. And many people have done this. I have done this.

Worth mentioning at this point: On a whim, I have placed Microflow's PGR-IV directly into the vascular system 6" ahead of the fruit at day 29 @ .02% with a hypodermic needle. PGR-IV is .0028% Indolebutric acid & .003% Gibberellic acid. The fruit yielded seeds that were much thicker than the mother (coincidence or influence?). The Mother 707 Toftness seed averaged 5-6mm for a medium seed. These progeny seeds are from an Aug 19th set. Treated 29 days later. Resulting seeds that formed average 6-8mm at the widest point when sampling 6 of the poorest quality (the better ones are in the freezer). Of interest is the fact that when this fruit was opened, only 140 fully developed seeds existed. But no "small whities" at all. Instead I found "hard green finger shaped masses" at the points where seeds should have developed. I wish now that I had weighed that fruit & compared the result to the tape. Tape had the est at 168-170 lbs.

<But on Halloween Eve, the Sawzall was mightier than the intellect>

**I can't wait to trial germinate a few of these fatties!**

12/4/2003 10:04:43 AM

[email protected]

This is a one off observation. Other environmental factors may have played a role. There were no same seed/plant checks to compare. Though other same patch/different plant fruit did contain undeveloped "whities" as one might expect to find in late sets. Even smaller fruit contained more seeds in number though more "typically sized". All other environmental factors & maintenance protocol were the same or similar.

Were this a planned experiment, checks would be needed. (as well as a larger patch-LOL) And I would not have reached for PGR-IV exclusively. But rather several PGR's to better control which hormones were the influencing factor & when. Cytokinin would need to be included in further studies. Whole plant foliar treatments should not be ruled out entirely. We don't know exactly where all the hormone production takes place in the plant. We only theorize that the act of pollination causes the trigger signal to fire. Vascular communication/triggering in other Cucurbita Maxima occurrs over long distances. AG's give us no reason think otherwise.

Timing is critical. I obviously interupted seed formation even as late as I intervened. Non destrctive commercial X-Ray sampling units are available but very expensive. I worked with these units in the early '80's. They were not portable at that time. Does anyone know if portable field imaging equipment exists today?


A link folks might find interesting:

http://www-plb.ucdavis.edu/labs/Lucas/pdfs/p202-209%20Ruis%20Madrano.pdf

More later

Steve

12/4/2003 10:04:54 AM

Stouffville

what do hormones do exactly in a plant and how do they do it?

12/4/2003 10:49:25 AM

[email protected]

Jammer,

Here's a primer on what & how.

http://www.plant-hormones.info/

12/4/2003 11:40:02 AM

[email protected]

This one should have been first:

http://extension.oregonstate.edu/mg/botany/hormones.html

12/4/2003 11:47:20 AM

Montoursville, PA

Someone has overlooked the best way that sap gets translocated, from within, the patch is the sight of a good looking gal with two tall cold ones, in tights sitting at the saps picnic table. Temperature tends to go up, blood circulation may improve and success, of another nature, can be achieved if there is anything like ability, to move, left, in the sap.

12/4/2003 3:51:30 PM

Carrollton, Ga.

What about a pumpkin that does not have any seeds in it. If I remember right Jerry Checkon's 1131 had no seeds or very few seeds in it.
Doug

12/4/2003 5:55:14 PM

[email protected]

Fine observation Doug. 935 Lloyd x 865 Mettler never threw more than 845 lbs until we look at the one that was grown without seeds. Was Mr. Checkon applying PGR's? Or did the plant respond favorably to the absence of seeds by producing it's own hormones? Or do seeds just make for a counter-productive sink? Remember the amino acid blocking theory that alters the sucrose to carbohydrate conversion.

12/4/2003 7:24:22 PM