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Netherlands

GPC chart statistics for all pumpkins taping and/or weighing more than 1700 lbs.

All pumpkins WEIGHING 1700lbs or more.

Old chart
2009 – 1 heavy, 0 light, average 2.0% heavy (total 1)
2010 – 1 heavy, 3 light, average 2.0% heavy (total 4)
2011 – 2 heavy, 4 light, average -1.7% heavy (total 6)
2012 – 7 heavy, 12 light, average -2.3% heavy (total 19)

New chart
2013 – 14 heavy (88%), 2 light (12%), average 7.1% heavy (total 16)
2014 – 44 heavy (77%), 13 light (23%), average 5.5% heavy (total 57)
2015 – 54 heavy (89%), 7 light (11%), average 8.2% heavy (total 61)
Average – 84% heavy, 16% light, 6.9% heavy

All pumpkins TAPING 1700lbs or more.

Old chart
2010 – 0 heavy, 3 light, average -3.7% heavy (total 3)
2011 – 1 heavy, 4 light, average -3.0% heavy (total 5)
2012 – 2 heavy, 12 light, average -6.4% heavy (total 14)

New chart
2013 – 5 heavy (71%), 2 light (19%), average 1.7% heavy (total 7)
2014 – 26 heavy (67%), 13 light (33%), average 2.3% heavy (total 39)
2015 – 25 heavy (81% ), 6 light (9%), average 4.7% heavy (total 31)
Average – 73% heavy, 27% light, 3.3% heavy

10/31/2015 7:20:40 AM

Netherlands

All pumpkins TAPING 1800lbs or more.
2013-2015 – 27 heavy (79%), 7 light (21%), average 4.8% heavy (total 34)

All pumpkins taping and/or weighing more than 1700lbs.
World: 6.9% heavy
California: 4.3% heavy
Europe: 4.8% heavy
New England (NH, CT, RI, MA): 6.6% heavy
Wisconsin/Minnesota: 10.6% heavy
2032 Mathison: -0.1% heavy
2009 Wallace: 4.7% heavy
1676 Daletas: 11.8% heavy

10/31/2015 7:21:00 AM

Netherlands

The only conclusions I would like to state is that the GPC chart gets less accurate as weights/measurements increase (especially over 1800lbs). At the time the chart was made, there were very few large pumpkins so the chart was theoretical and no fault of those who put it together.

Secondly, heat seems to affect % heavy. California being the hottest, Europe growing almost exclusively in greenhouses and Wisconsin/Minnesota being the coldest. Moderate climates, such as New England, match the world average.

10/31/2015 7:28:25 AM

Netherlands

Thirdly, genetics play a very important role in going heavy or not.

10/31/2015 7:29:39 AM

N.c.

Thanks Brad!

10/31/2015 9:33:01 AM

South Hero, VT

Very informative!


Thank you very much!

10/31/2015 1:04:06 PM

N.c.

In 2015 there were 61 pumpkins that weighed over 1700 pounds.
In 2015 there were 31 pumpkins that taped over 1700 pounds.
So then in 2015 there were 30 pumpkins that weighed over 1700 pounds yet taped under 1700 pounds so 50% of the pumpkins weighing over 1700 taped under 1700 pounds

If we know that 50% of the 1700 lb.+ pumpkins were taping under 1700 pounds then only 31% of the pumpkins weighing and taping over 1700 pounds went heavy? That does not seem all that unusual to me.

10/31/2015 5:45:14 PM

East Jordan, MI

I think if you will perform the same exercise using the Team Pumpkin Chart

http://team-pumpkin.org/downloads/Team-Pumpkin_2013_Enhanced_OTT_Chart.pdf

you will find that it is much more accurate with the pumpkins over 1600 lbs than the current GPC chart. That is about where the charts diverge.

10/31/2015 6:37:59 PM

N.c.

If we look at the intro to the team pumpkin chart we see that the motivating factor to building a new chart was the instance of too many pumpkins going "lite to the chart". If we look at the GPC intro to the new chart we see that the motivation for a new chart was too many pumpkins going heavy. So if team pumpkin is right then perhaps it is the case that there are some percentage of sigmoidal functions that are driving pumpkin weights. If the GPC is right then the growth slope should be steeper. Who knows?

10/31/2015 11:41:50 PM

Netherlands

"31% of the pumpkins weighing and taping over 1700 pounds went heavy"

No,this is 73%. At 1800 pounds it goes to 79%. I didn't check out 1900-2000+ because I believe there is not enough data yet to state anything for certain.

The purpose of this exercise was to see if pumpkins are getting heavier to the charts over the years, what genetics do and what climate does.

I suspect fertilization/soil type also plays a role but don't have the data to prove this.

From several studies and my own observations, it is clear that the ideal temperature for growing pumpkins is 25-26C (77-80F). The closer we can get to that, the compacter the pumpkins will be (and heavier to the charts) and the bigger the chance the really big ones make it to the scales.

11/1/2015 10:23:38 AM

nOVA sCOTIA

its too bad we can't get some input on fertilization and soil type Brad? If you look back on results over the last number of years there are certain growers that consistently pull pumpkins out of their patch that are thicker than cement. In fear of being crucified i will not mention names!

11/1/2015 2:36:13 PM

N.c.

Hey Brad!
Yes I was wrong in what I said, here is what I should have said:

I was actually only looking at the pumpkins grown in 2015 and those that weighed AND taped over 1700 pounds.

In your data you have that in 2015 there were 61 pumpkins grown that weighed 1700 pounds or more and that 89% went heavy.

Also in your data you have that in 2015 there were 31 pumpkins grown that taped 1700 pounds or more and that 81% went heavy.

I subtracted the 31 pumpkins that taped +1700 from the 61 pumpkins that weighed +1700. I infer that 30 pumpkins (of the 61 pumpkins grown that weighed 1700 pounds or more) or roughly 50% taped less than 1700 pounds but weighed 1700 pounds or more. I then subtracted these 30 pumpkins which weighed more than 1700 pounds but taped less than 1700 pounds from the total percentage of pumpkins going heavy. I come up with 89% (total that went heavy) minus 50% (total that went heavy yet which taped less than 1700 pounds but weighed over 1700 pounds) to come up with the following.
In 2015 39% of the pumpkins that taped over 1700 pounds and weighed over 1700 pounds went heavy. Which is not too bad if we are assuming that if the chart were correct 50% should go heavy and 50% should go lite.

All that aside thanks for the data.

11/1/2015 8:07:43 PM

Rhode Island

donkin theres plenty of information available. its who you ask and what that person may or may not know and willing to share that is the fact of the matter.

ron and i have always shared any info we have thats lead to our results.its called payback for the likes of many great growers who hekped ron and i get our start in the hobby.
especially thankful of ron who has spoke and lectured at numerous seminars over the years.

growing a true giant does not happen by accident,
to be consistant at this crazy hobby of ours? you research,review and plan year long.

you pray for great weather to go along with all the info and supplies you have at the ready.
the rest as the saying goes"depends on lady luck"

as far as chart accuracy goes. we use both charts as a guide but know the true judge? is that 4ft x 4ft scale we weigh on.

pap

11/1/2015 8:26:54 PM

N.c.

Thanks for chiming in Pap! I still have a 1789 or two you guys sent me which I did not even ask for. Could you say what type of soil you have? Could you say what your percentages of sand, silt and clay are?

11/1/2015 8:49:02 PM

N.c.

For those who are interested in finding out what type of soil you have and what the percentages of sand,soil and clay are go here.


http://mea.com.au/soil-plants-climate/soil-moisture-monitoring/learning-centre/what-is-soil-texture

11/1/2015 9:50:22 PM

N.c.

Good Gourd! I am wrong again. The following sentence may be correct.
In 2015 of the 31 pumpkins that taped and weighed over 1700 pounds, 77% went heavy.

11/2/2015 6:04:51 AM

Menomonie, WI (mail@gr8pumpkin.net)

OK so if heavy is a factor for consideration for planting. If I plant two seeds and cross them, should I not expect heavy. Which then gives you the desired results, in which the charts make perfect sense.

11/2/2015 7:34:53 AM

Rhode Island

condo

we have a sandy loose type of soil (very good drainage so we are able to water quite often during each week), especially this summer when we had pretty much no rain all summer.

this fall we added twelve yards each of fully dried/composted leaves,fully dried/composted chicken manure and fully dried/composted municipal compost to our patches we are are prepping for next season.then we planted our winter rye. previous to this patch because we were resting it for several years we had a patch full of zinnias growing all summer. tilled it in three weeks before adding amendments and rye.

this area will grow five plants and is very close or a tad over 4,500 sq ft.

our patches have very little clay in them. not enough to even worry about the amt.

**never use fresh manure be it chicken,cow,pig,duck.or whatever. brings in lots of disease and will set your patch back several years.

i know because we did it to one patch many years ago and it took many more seasons to eliminate problems in that area.

pap wallace

11/2/2015 5:39:19 PM

N.c.

Thanks Pap!

11/2/2015 6:12:57 PM

N.c.

Shannon if the chart is right then 50% of the pumpkins should go heavy and 50% should go lite. 0% average + or - not 8.2% heavy as in 2015.

11/2/2015 6:20:02 PM

Oak Grove, Mn

can someone explain to me why heavy or light really makes any difference in seed choices to plant. It seems to me that a 1500 pound pumpkin that went 10% light from its ott measurement would be just as desirable as a 1500 pound pumpkin that went 10% heavy from its ott measurement. In fact, in my eyes, it might be more desirable, if you consider that worlds largest pumpkin right now is only weight...and not by volume. If there was a volume record also...the light ones would shine

11/2/2015 6:29:55 PM

Oak Grove, Mn

building a very accurate volume measurement tester would not be that difficult

11/2/2015 6:32:03 PM

Willamette Valley, Oregon

The best way to assess chart accuracy is by looking at OTT ranges not by weight cut offs, so Brad's "TAPING" calculations are the ones to look at.

A properly functioning chart mathematically SHOULD be heavy when sorted by weight. The fact that other charts are to-chart or light-to-chart when using a weight cut off is an indication of the error in those charts.

Here's a graph that helps explains what the problem is with using a weight cut off not an OTT cut off: http://www.bigpumpkins.com/displayphoto.asp?pid=7411&gid=1

Basically a weight cut off throws out all the light-to-chart pumpkins, so it's no surprise that the remaining ones average heavy-to-chart.

11/2/2015 7:56:59 PM

Netherlands

bnot, the explanation is that light means thinner walls and thinner walls means a higher risk of splitting. That being said, heavy ones also split, but if you look at the statistics, the winners are always the heavy ones and not the light ones.

11/3/2015 4:40:07 AM

N.c.

So I made a graph depicting the relationship between the GPC/Team Pumpkin tables and pumpkins actually grown. The line representing pumpkins actually grown that 'grew to chart' crossed over the lines representing GPC/Team Pumpkin tables around 1680 pounds. The number of pumpkins going over the charts looks to be most acute in the 1900 pound range. At perhaps the 1975 pound area the apogee is reached and the percentage of pumpkins going over the charts will begin to fall. Meier's 2323 pumpkin plots below the lines that describe the GPC/Team Pumpkin charts. When the time comes that a number of people are producing pumpkins in the 2200 pound range they will be complaining that their pumpkins are going lite. For my X axis I used weight (pounds) ascending in 25 pound increments. For my Y axis I used (OTT) inches ascending in 3 inch increments. I plotted pumpkins using pumpkin fanatic data and used their calculations of heavy or light. I started with the heaviest pumpkins and worked backwards. I noted the pumpkins that went to the chart ( + or - 2% ) and drew a line between them. I took numbers from the GPC chart and the Team Pumpkin chart in 10 pound increments to chart their respective lines. The result was a very cool graph with the "to the chart pumpkins" describing an ogee sigmoidal curve representing the "to the chart" pumpkins over 1700 pounds. All I need now is a lot of growers growing pumpkins over 1900 pounds to see if I am correct!

11/4/2015 9:51:46 PM

nOVA sCOTIA

what you need to do is get out and grow a dam pumpkin...lol

11/5/2015 5:44:51 AM

N.c.

Ahhhahaha!

11/5/2015 6:02:03 AM

nOVA sCOTIA

well,well,well i finally found an American with a sense of humor...ahaaa

11/5/2015 6:25:55 AM

East Jordan, MI

where is the graph you made condo?

11/5/2015 7:54:24 PM

N.c.

Cntryboy that graph was wrong. That graph which is on a sheet of graph paper used a run of 8 (pounds) to a rise of 1(inch). It was fairly nonsensical. I made another graph using weight increasing by 12 pounds per unit as the inches rise at 1 inch per unit. It was much closer to right. It shows the chart lines in a fairly straight line, ascending from left to right. The line representing 'to the chart pumpkins' is a fairly straight line which deviates from the chart line around 1540 pounds and continues away from the chart lines uniformly (like a sideways V). Today I am going to plot another graph using a rise of 1 and a run of 15. This should overlay the 'to the chart' lines closely over the line representing pumpkins that grew to the chart.

11/6/2015 7:32:15 AM

N.c.

I put some photos in the photo gallery but they are not up yet.

11/6/2015 11:43:17 AM

Indiana

After emailing back and forth with Scott and Bart, I figured out the differences and how to use the charts.

The GPC chart measures genetic % heavy. It will only need adjusted when the average population of what is planted changes genetically. It is not the most accurate way to predict the top end of the pumpkin ott range. The GPC chart predicts the average weight for pumpkins weighed at a certain size.

The Team Pumpkin chart predicts the weights. It is skewed at the top end to take into account the thicker walls of the genetically superior pumpkins that end up the leaders. This chart comes in the back door and predicts the size for a specific weight. That is why the chart has to be adjusted all the time at the top end. The first pumpkins to get to certain weights in general are less prone to split, the primary reason wall thickness.

Conclusion. Use the GPC chart for comparing pumpkins. If you have a really big pumpkin say over 1700 pounds, use the team pumpkin chart to more closely know what your pumpkin will likely weigh.

Does this help people understand them better?

11/7/2015 12:12:22 AM

Netherlands

Thanks for the explanation Tom. I observed the same.

11/7/2015 5:51:47 AM

Willamette Valley, Oregon

An OTT chart should be good for two main uses:

1. Estimating pumpkin weights from OTT before it's weighed. (pre weigh-off)
2. Determining if a given fruit is light or heavy to chart FOR ITS SIZE, for seed selection purposes. (post weigh-off)

Both involve using OTT to predict weight since that is the sole thing that any OTT chart does directly: predict weight from OTT.

To avoid any bias, both uses should be approached from the OTT side not the weight side. % to chart is fundamentally an OTT-based (ie volume-based) calculation. (is it heavy or light FOR ITS VOLUME?)

Sorting by weight necessarily excludes light pumpkins so that method of chart assessment will yield a biased and incorrect answer, because it's just not the right question to ask. You can ask the question: "Is it heavy or light for it's weight?", but that's not what you really want to know. You want to know if it's heavy or light FOR ITS SIZE. That may be the key to the misunderstanding folks have. (Sorting by weight makes it appear that charts produce heavy pumpkins when it's at least partly a math thing, not a chart error.)

Think about it this way... A grower doesn't know his/her pumpkin is over 1700 lbs, say, until it's weighed. That's why it's fundamentally inappropriate to judge the chart starting from the weight side (i.e. weight cut-offs). Before weighing we only know OTTs. If we already knew the weight, then predicting the weight would be...well...pretty easy, I hope (since you know it precisely). ha! But even after the weigh off when the weight is known, it's still inappropriate mathematically to assess percent chart for a group of pumpkins over a certain weight.

I agree it's not entirely intuitive, so I'm not trying to make fun of anyone here. Just trying to explain it.

See my post above and that graph too. If that graph isn't completely clear I could try to explain it more.

11/9/2015 4:03:27 PM

Willamette Valley, Oregon

Having said that....

when a proper OTT-based assessment is done on both charts, neither chart is doing exceptionally well at predicting the weights of the highest OTTs in 2015.

Top 10 by OTT (461" to 477") in 2015:
GPC= +4.2%
TP= -6.1%

Top 50 by OTT (432" to 477") in 2015:
GPC= +3.9%
TP= -3.1

This year was heavier than average by about 1-2 percentage points on both charts:

Overall % to chart (top to bottom OTTs) 2015 / 2014:
GCP +1.0% / -0.3%
TP= +1.8% / +0.6%

11/9/2015 4:37:01 PM

Wallingford,CT

You should only use a tool for the task for which it is designed. There is a reason the Team-Pumpkin Enhanced Chart has a portion with a grey background starting at 459 OTT. The last paragraph of my article says “Even with the enhanced chart method you should use caution when interpreting you pumpkin based on the highest ranges (gray background). Extrapolation is risky and there is suggestion the form of the curve/equation may change with new data.”

11/9/2015 8:19:11 PM

Rudolph

Lol, to much goes into the ott... At the end of the day it is what it is...ott wont change that.

11/9/2015 9:48:43 PM

Netherlands

The reason I looked into the data in the first place was to see what causes heavy or light. With that information you can possibly change your growing strategies.

The reason why pumpkins in general went heavier this year than last year is likely because the heaviest pumpkins moved from California to Wisconsin, or in any case from warmer climates to colder ones.

11/10/2015 2:52:03 AM

Knopp, Germany

The BS stops when the tailgate drops

11/10/2015 10:08:33 AM

nOVA sCOTIA

what are you looking for Brad ?...lol

11/10/2015 10:21:33 AM

Netherlands

I noticed that pumpkins grown in greenhouses here in Europe tend to go light (mine go really light). I figured if I get all the information from across the globe, I might figure out if it was our/my soil, the heat, or something else. It seems to be the heat so I made the sides of my new polytunnel roll up and put in a big window in the old polytunnel. Ready for next year.

11/10/2015 1:10:37 PM

N.c.

So I am looking at this chart:

http://greatpumpkincommonwealth.com/PDF/2012chart.pdf

But none of these pumpkin estimated weights:

http://www.bigpumpkins.com/WeighoffResultsGPC.aspx?c=P&y=2015

seem to match that chart. Is there another chart? What am I missing?

11/13/2015 9:02:14 AM

N.c.

Good Gourd! I got it now.


http://greatpumpkincommonwealth.com/PDF/chartscombined.pdf

11/13/2015 9:20:57 AM

Netherlands

A professional Dutch sweet pepper grower just emailed me to say that peppers go up to 40 grams lighter during hot summers, compared to spring and fall when the greenhouse has the ideal temperature. That's about 1/5th its weight.

11/13/2015 10:11:26 AM