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Rush, NY

I have summarized the Actual wieghts versus OTT Estimated weights (Martin/Stellpflug Tables) for 2001 fruit over 900 pounds and WILL NOT update this year, even tho we now have double the amount of data for fruit over 1000 pounds. For 23 fruit (over 1000) in the AGGC data base with OTT data, the average estimate was 8.6 pounds (0.8%) under the actual average weight. This is a pretty small deviation considering the DEVIATION RANGE was 271.5 pounds or 26%..........For the 3 fruit over 1200 pounds the average weight was 1251 pounds and the average estimate was 1266 pounds. The 15 pound difference is small considering the estimates ranged fron 160 pounds OVER to 203 pounds UNDER (363 pound range).
NOTE: Most of the estimates in the AGGC file have been based on the Marcellus equation, which underestimates, on average, for fruit over approximately 600 pounds. For the 3 fruit over 1200 pounds, it underestimated by an average of 81 pounds. Mike is going to change the estimates in his data base to the Martin/Stellpflug Equation.

12/16/2001 7:36:46 AM

Riverton, WY

Len
I've heard of the Martin/Stellpflug Tables, but I didn't realize there was a formula associated with it. Would it be possible to share the formula with us? Thanks!
Ron

12/16/2001 10:17:35 PM

Rexburg, Idaho

Len, Thanks for the hard work it benefits the entire pumpkin growing community.

12/17/2001 8:22:30 AM

Utah

All-

I have a excel spread sheet the uses the Marcellus estimation equation. someone else originally made it and i modified it some to suit my needs. you input the 3 OTT measurement and it gives you the estimated weight and change in weigh from the last measurement. Plus it has two graphs, total weight and daily weight gain.

I'll email it to anyone who is interested.
email me at [email protected] and I'll send it out to you.
I know Len has some good equations also, i just haven't set anything up with his yet.
Ron the equation i have is:
(OTT^^2.76)x0.0000795
^^= to the power of

gordon

12/17/2001 10:12:02 AM

Utah

forgot to metion that there is also are spots for keeping track of the weather and comments.
plus you can get a daily or weekly version.
gordon

12/17/2001 11:21:55 AM

Rush, NY

I will attach a copy of the 2001 Martin/Stellpflug equations to anyone that can make good use of them. They are not simple equations as they have Constant, Linear, Squared and Cubed terms. E-mail me if you want a copy.

For those using the Marcellus Equations you should be aware that they overestimate a little (up to 10 pounds) under 600 pounds and underestimate above that. At 1100 pounds, they underestimate by over 50 pounds. They are pretty good up to 750 pounds. They need to be updated as they were based on what data we had in 1990, when the largest fruit was 821 pounds.

12/17/2001 3:29:29 PM

South Hill, Virginia

I have been very impressed with the accuracy of these tables. If the same person was measuring all these pumpkins they would be even more accurate. Since the Martin/Stellpflug is a third order equation a small measuring error can make for very large variation in a weight estimate. When measuring a smaller pumpkins an inch of OTT only means a pound or two but for a 1200 lber each inch can mean somewhere around 10 pounds. Anyway, I'm rambling.....I just appreciate being able to take a few simple measurements of a very irregular object and get a damn good weight estimate.

12/17/2001 4:20:27 PM