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Ontario, Canada.

Yes its back our annual topic....The Sink Source Relationship discussion is back..................

Its time to share what is new and what is old...

Here are some of my new findings...

Calcium is not very mobile in the plant and moves mainly in the xylem. It is carried in the transpiration stream from the roots to the leaves. The driving force for water movement through the tree is evaporation from the leaves and the movement of water to the leaves carries calcium with it. Calcium is also not usually mobile in the phloem, which carries sugars from the leaves to the developing fruit. Therefore, BES can be viewed as a competition between the shoots and the fruit for calcium.

Several factors can affect fruit uptake of calcium in the early summer leading up to and after fruit set. High levels of ammonium nitrogen, potassium, and magnesium all reduce the fruit uptake of calcium. This is because nitrogen favors shoot growth over fruit growth. Potassium and magnesium compete with calcium because they are all positively charged ions. High levels of available water will increase fruit calcium if shoot growth is not excessive. In general, lessening shoot growth increases calcium uptake by the fruit. Increasing root growth results in increased uptake of calcium. Finally, maintaining a high photosynthetic rate will increase calcium in the fruit as long as shoot growth is not excessive.

Many of the practices which we employ as growers to maintain vigor in the plants canopy can come back to haunt us if we do not also manage vegetative vigor. Maintaining a large growing leafed plant while attempting pollination is fruit cannibalistic.

I would like to discuss the practices we can use to control BES further.

2/8/2008 9:10:30 AM

Ohio

Russ, this might be a little off topic but what do you think Calcium applied straight to the pumpkin does? Do you think the skin of the pumpkin absorbs any of it at all? I have seen before weigh offs where guys will drench a sheet down with calcium and a couple hours before its weighed in take the soaked calcium sheet off(perfectly legal). Do you think any of this calcium is absorbed by the skin to get that little extra advantage? I'm not sure if this would help any because the skin on a pumpkin has no pores to absorb it? To me it would kinda be like soaking down concrete, once it dries it just evaporates.

2/8/2008 9:32:25 AM

Ontario, Canada.

Brooks, tthe simply answer is no. I don't believe it works there are several reasons for this. Largely though the fruit at this late stage of its development transpires very little as it has long ago begun to shut the outside world out to allow its seeds to develop protected deep inside the blanketed layers of the fruit.

2/8/2008 3:06:06 PM

Ohio

Just thought of this Russ.
While the pumpkin is sitting there cut from the vine, maybe they do this calcium rap to keep mostier(sp) in the pumpkin so it doesn't lose any weight before its weighed,,, maybe? I dunno?

2/8/2008 7:57:40 PM

Cincinnati,OH

Brooks what was the calcium reading on your soil test last year? That was a killer thick blossom end on your 1402.

2/8/2008 8:16:59 PM

Minnesota

I thought a thick blossom end was due to genetics? Not calcium. Am i wrong here?

2/8/2008 9:28:04 PM

Phoenix, AZ

Since you are talking about BES and Ca within fruit, it made me go back to a post this last summer where I showed in my fruit that I had minimal Ca in the flesh. granted, this was from my plant that was Ca deficient overall but even if you triple the Ca in the fruit, it is not much.

Personally, I put a lot more focus on Boron. It is responsible for cell flexibility and B helps the uptake of Ca.

Just trying to send you in different directions since we are all trying to learn something new here.

Original Post:

http://www.bigpumpkins.com/MsgBoard/ViewThread.asp?b=3&p=203501

2/8/2008 9:31:23 PM

Clayton Cal

kahuna6 could you bee a little more detailed in your theory about bees -are you trying to say that bees foraging for nectar are robing the plant of important sugars that have an impact on calcium -for that fruit -if calcium dosent move freely through out the plant -then it is only impacting the fruit on which the blossom is located - if it is not a keeper then whats the difference-nectar is only available for a very short window -or are you talking about something else i am curious-i always thought that bees helped stimulate the plant in a positive growth manner-RDY-B

2/8/2008 9:36:37 PM

Cincinnati,OH

BES = blossom end split. Oh no I said it out loud.

2/8/2008 10:29:16 PM

Clayton Cal

RON RAHE- hows that work-never herd of that very interesting can you tell-us what goes on with the bees and split blossom ends-learning all the time-RDY-B

2/8/2008 10:56:51 PM

Ontario, Canada.

Ben yes you are so very correct. Boron and Calcium go hand in hand when talking about BES.

RDY-B, surely U R Joking? Right!

2/8/2008 11:09:02 PM

Ontario, Canada.

Ron, Sadly so many still equate Ca ppm to the problem. It is not usually an issue at all. It is about availability, uptake, mobility and transpiration.

Boron like Ca is a positiely charged ion in the soil. Anything that affects either of these two elements in the soil restricts uptake. Ca an B also moves in the Xylem to the evaporative parts of the plant. Therefore the highest concentrations will be found within the leaves. However mobility out of the leaves is very restricted and only occurs in very rare conditions and extreme conditions. Figure that out and you've got the key.

If you are not up on this topic I suggest some basic sites with which to help you.

http://www.spectrumanalytic.com/support/library/ff/Ca_Basics.htm

Low humidity causes high transpiration rates out of the leaves and directs more mass flow to the leaves and directs Ca and B away from the sink. The leaves become the plants radiator. The energy is directed to the elephants ears for cooling. This is also one of the primary causes of Dill rings. Combine this with speedy growth and dry soil just before such an event. Your fruit is now left starving for Calcium and Boron. Deep rib splits, sag lines and blossom end splits are usually not good friends of heavy fruit.

2/8/2008 11:22:11 PM

Clayton Cal

no joke how do the bees affect calcium -DR DONALD HORNECK -agronomist says calcium dose not move stays in one place in the tissue-please explain many people would like to hear more about your desire to control bees

2/8/2008 11:55:20 PM

Minnesota(dw447@fastmail.fm)

RDY-B.....BES stands for Blossom End Splits(like USA stands for United States of America).....nothing to do with bees that I know of. I hope this helps.

2/9/2008 12:10:06 AM

Clayton Cal

thankyou very much i will now go and get my eyes checked-my problem is i know more about bees than pumpkins maybe you will find this funy i hope so -sory -RDY-B

2/9/2008 12:17:04 AM

Minnesota

You probably won't have a problem pollinating. He He He

2/9/2008 12:56:53 AM

Minnesota(dw447@fastmail.fm)

It was a humorous few posts. Thanks for the laugh. Everyone makes mistakes.

2/9/2008 1:16:03 AM

Cincinnati,OH

Kahuna,I guess thats why Paps is always reminding us that we aren't growing lettuce.

2/9/2008 11:24:12 AM