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maine USA

Tremor wrote: That plant also had fusarium & he lost the crown EARLY. So by back-feeding with 120 sq ft of (mostly) forward secondaries he still managed another 800 lbs!!!
In case I ever need to do this back feeding of mostly forward secondaries, what does this Mean? thanks KathyT

1/5/2007 11:45:47 PM

Bristol, ME ([email protected])

Kathy,
There has been debate for years, although I think it's unwaranted debate, about whether the plant forward of the fruit contributes to feeding the fruit as much, if at all, than the portion behind the plant. So back feeding is so called flow of nutrients in the plant traveling in the opposite direction so to speak..i.e. flowing from tip toward crown instead of the normal crown to tip direction.

If you think about it, the debate is unfounded because all your secondaries are pushing nutrients from tip to base before they get to the main, regardless of where the secondary is located on the plant so obviously backfeeding is possible and common.
Hope this helps and I didn't babble too much.

1/6/2007 7:04:51 AM

[email protected]

Try doing a search here at BP for the word "sink" for some very energetic debates about wether, how & when the plant decides it will start "back feeding".

There is no question at all that an AG plant can sense where the photosynthate is needed (sink) & then make it go there. It stands to reason that when the main is lost near the fruit & the fruit still keeps growing that some area forward of the fruit (source) is responsible.

It's never been done with AG's, but some researchers once injected cucrbita pepo with a radio isotope & measured the rate & distance of photosynthate transport. Unfortunately they didn't record the direction of transport.

1/6/2007 11:42:22 AM

Ohio

Ive seen a plant back feed first hand, there is no other way it could grow except by back feeding. I lost my entire main just a foot or so before a 100lb pumpkin on July 31st, I had at best 100sq ft of plant past the pumpkin, it ended up 604 lbs. Believe me, there is back feeding going on.

Brooks

1/6/2007 3:44:11 PM

maine USA

Thanks guys, this was a big help. KathyT

1/6/2007 3:54:48 PM

Montoursville, PA

Kathy.........think of the total plant being the stomach for the fruit or sink if you wish to be correct. Take away or preventing the total to work just would not make sense.

1/7/2007 11:08:48 AM

Oz

What is the "action" that pushes/pulls the nutrients through the vine?

1/8/2007 10:10:09 AM

[email protected]

The "sink" is the developing fruit. The "source" is all of the photosynthate producing roots & leaves. As the theory goes, wherever the sink is the source is supposed to detect it & feed it. Logically & as we have all probably noticed, the part of the plant closest to the crown always has first dibs on feeding the sink. But if something happens to the crown side, the "source" after the sink (fruit) will start back-feeding to keep the all-important seed producer growing.

Tracing what part the classic X-mas tree pattern feeds the sink & by how much can be done with radioactive dyes. Of course we can also see this area on hot days or when the vasculat system is streesed by wilting. Joe & I even thorized that food grade dyes might be used to "see" where the sap goes but no one has the time to do this.

Where it gets interesting is in figuring out what causes this to happen. Developing seeds are known to produce certain hormones. Researchers have noted that hormones are often used by plants to send "chemical signals". Pumpkin seeds are probably sending signals to the "source" which regulates the photosynthate (sap) direction. This has been confirmed in other species.

So naturally a mad scientists wants to know which hormone it is & so as to try to use it to trick the plant into feeding sap toward the fruit from both ends instead of just one. LOL Which hormone & where & when it should be adminstered? I don't know.

I am not aware of any successes but IF it could be done....LOL

continued

1/8/2007 10:48:14 AM

[email protected]

Joe Ailts was studying this & we spent some time discussing it a few years ago. At the time I found some old online documents published by various edu's that support the theory. The trouble would be in finding a practical application for this sort of arcane information.

I went way out on a limb & suggested that a perthocarpic pumpkin (seedless) might be more prone to mixing up the signals. I sited the 1131 Checkon as an example of an unusaully high weight fruit (for the mothers track record) that failed to contain any seeds. There are hormones (abscisic acid) that can be used to induce parthenocarpy in some species. I managed to get a hold of some but never had the nerve to withold male pollen on "the day" since a failure would mean no pumpkin at all.

It would be a fun project for a grower who has more time & space than me. LOL

1/8/2007 10:48:18 AM

[email protected]

Jeez! I gotta remember to proof read but pressed for time.

"Parthenocarpic" fruit have no seeds. A search of that word here at BP or elsewhere might be fun.

1/8/2007 10:51:31 AM

Little-TON - Colorado

Geez Tremor..... you ever think of going onto Jeopardy?

1/8/2007 12:41:49 PM

[email protected]

Jeopardy for Green Industry Geeks?

1/8/2007 1:22:21 PM