How Big Will That Tomato Get?

Based upon fruit dimension data collected every day for 102 days on my largest tomato to date (Big Zac (3.486 DT 2012)), I developed a polynomial formula which fits the data very well for the first 50 days.

Y = 0.0052X + 0.0034X^2 – 0.00004X^3

Where X = Number of days since fruit set and Y = Weight of tomato

This formula produces a shallow sigmoidal curve, with the cubic term accounting largely for the substantial slowing of growth as the tomato approaches ripe stage. R^2 for this formula is 0.9986, so it is a very tight fit – at least for a 3-1/2 lb. tomato grown in the Salt Lake Valley from 25 August to 06 December 2012.

So what would such a formula look like for a tomato that reaches 8 lbs. by day 50? Well, it’s conjecture of course, but assuming the growth curve would have a similar shape, I propose something like:

Y = 0.009X + 0.00577X^2 – 0.000055X^3

Around here, tomatoes ripen in 36-42 days during the heat of summer, but I’ve recorded 50+ days on occasion; 70+ days is a very real possibility for those that set fruit from late August to mid-September.

Currently, the fastest growing tomato remains the 8X (up to 14X?) Michael’s Portuguese monster, now measuring to 0.868 lb.:

Michael's Portuguese Monster (2.610 DT 2012) HT001 7-25-2014 B rev Michael's Portuguese Monster (2.610 DT 2012) HT001 7-25-2014 D rev

To be on target for 8 lbs., it would need to weigh about 0.970 lb. at this point.  It’s already a day behind schedule!  Prediction is rarely an exact science, at least not in the realm of biology, and weights are best estimates only.  But my largest from 2012 weighed only 0.302 lbs. at this point!

OK, here we go! An unwritten goal is only a wish, so I’ve decided to boldly publish daily goals for this tomato. Based upon the formula written in bold above, following is a list of daily target weights (TW), followed by estimated weights (EW) taken from caliper measurements.  First column is days since fruit set (DS).

DS —- Date —- TW —- EW

1 —- 13 July —- 0.015 —-
2 —- 14 July —- 0.041 —-
3 —- 15 July —- 0.077 —-
4 —- 16 July —- 0.12 —-
5 —- 17 July —- 0.18 —-
6 —- 18 July —- 0.25 —-
7 —- 19 July —- 0.33 —- 0.13
8 —- 20 July —- 0.41 —-?
9 —- 21 July —- 0.51 —- 0.27
10 —- 22 July —- 0.61 —-?
11 —- 23 July —- 0.72 —- 0.57
12 —- 24 July —- 0.84 —-?
13 —- 25 July —- 0.97 —- 0.87
14 —- 26 July —- 1.11 —- 1.02
15 —- 27 July —- 1.25 —- 1.18
16 —- 28 July —- 1.40 —- 1.26
17 —- 29 July —- 1.55 —- 1.46 – see pic below
18 —- 30 July —- 1.71 —- 1.67 – this is 2.6 times larger than any tomato I’ve measured at 18 days
19 —- 31 July —- 1.88 —- 1.79
20 —- 01 Aug —- 2.05 —- 1.93
21 —- 02 Aug —- 2.22 —- 2.11 – see latest pics below. My previous largest measured to 0.67 lb. at this stage and took 41 days to reach this size.
22 —- 03 Aug —- 2.41 —- 2.25
23 —- 04 Aug —- 2.59 —- 2.28
24 —- 05 Aug —- 2.78 —- 2.55
25 —- 06 Aug —- 2.97 —- 2.73
26 —- 07 Aug —- 3.17 —- 2.89
27 —- 08 Aug —- 3.37 —- 2.91
28 —- 09 Aug —- 3.57 —- 2.93
29 —- 10 Aug —- 3.77 —- 3.08 – obviously slowing down. Latest pic below
30 —- 11 Aug —- 3.98 —- 3.18 – still 2.5 times larger than my biggest was at 30 days
31 —- 12 Aug —- 4.19 —- 3.29 – between days 11-26 gain was 0.16 lbs./day avg.; only 0.08 since
32 —- 13 Aug —- 4.39 —- 3.34
33 —- 14 Aug —- 4.60 —- 3.56 – on target for 4.5 to 5.0 lb. range, if it lasts until 50 days
34 —- 15 Aug —- 4.81 —- 3.70
35 —- 16 Aug —- 5.03 —- 3.82 – FIRST BLUSH; not going to get 50 days out of this one!  Expect shrinkage over the next 3 days as starches are converted to sugars and fruit density increases, then  brief and minor growth until fully ripe and at its heaviest.  Looks like even 4 lbs. might be a long shot.
36 —- 17 Aug —- 5.24 —- 3.98 – Ripening very fast; with so many bumps and crevices  I’ll probably need to subtract about 15% to get a weight estimate close to reality.  Possibility of breaking through the 4 lb. barrier is fading but still a good chance at breaking the Utah state record.
37 —- 18 Aug —- 5.45 —- 3.91 – Taped circumference = 20.9″, latest pics below
38 —- 19 Aug —- 5.66 —- 4.17 – Much cooler weather in the forecast, perhaps it will last another 6 days?
39 —- 20 Aug —- 5.86 —- 4.37 – Also indirectly weighed this tomato using a water displacement method and came up with 4.07 lbs.; see pics below.
40 —- 21 Aug —- 6.07 —- 4.66 – Now that it is fully ripe, switched to a DAF (Density Adjustment Factor) of 0.95 rather than 0.90, but this estimate is probably at least 1/2 pound heavy; Official weigh-off for a new state record set for Monday, 8-25 at 9:00 a.m.; latest pics below.
41 —- 22 Aug —- 6.28 —- 4.70 – Gave it one last very heavy dose of fish emulsion, seaweed extract, etc. hoping to coax a couple more ounces out of it over the weekend.
42 —- 23 Aug —- 6.48 —- 4.75 – Taped circumference = 21.7″
43 —- 24 Aug —- 6.68 —- 4.78 – Discussion and final pics below
44 —- 25 Aug —- 6.88 —- 3.754 lb. OFFICIAL CERTIFIED WEIGHT; pics etc. below
45 —- 26 Aug —- 7.08 —-
46 —- 27 Aug —- 7.27 —-
47 —- 28 Aug —- 7.46 —-
48 —- 29 Aug —- 7.64 —-
49 —- 30 Aug —- 7.82 —-
50 —- 31 Aug —- 8.01 —-

I will fill in this table periodically.  In an effort to encourage this tomato to catch up to the schedule, I’ve applied 10 gallons of my best compost – which is loaded with red wriggler worms! – to the surface, hoping the tomato roots will grow up into it and extract the necessary nutrients needed to reach 8 lbs.  I then covered this with grass clippings so the entire mound is about 8″ deep against the main stem, then tapering out.

Compost with Red Wriggler worms D

Compost with Red Wriggler worms E rev

New pic, 7-29-2014, 17 days since fruit set and about 1.46 lb.:

Michael's Portuguese Monster (2.610 DT 2012) HT001 7-29-2014 B rev

Latest pics, 8-2-2014, 21 days since fruit set, about 2.11 lb.:

Michael's Portuguese Monster (2.610 DT 2012) HT001 8-02-2014 A rev

Michael's Portuguese Monster (2.610 DT 2012) HT001 8-02-2014 F rev

Latest pic, 8-10-2014, 29 days since fruit set, about 3.08 lbs.  Sling is big enough and strong enough to hold a bowling ball!  Note the new digital calipers.  These will measure to 12″ diameter and are precise to 0.01mm.  Widest diameter needs to get to at least 240mm to have any hope of hitting 8 lbs.!

Michael's Portuguese Monster (2.610 DT 2012) HT001 8-10-2014 B rev

Latest pics, 8-18-2014, 37 days since fruit set, measures to 3.91 lbs., CC = 20.9″, very unlikely to break 4 lbs.

Michael's Portuguese Monster (2.610 DT 2012) HT001 8-18-2014 D Michael's Portuguese Monster (2.610 DT 2012) HT001 8-18-2014 K

Latest pics, 8-20, showing indirect weighing with a water displacement method.  The fruit displaced 1,945 g of water, with some error because the stem prevented full immersion.  After adjusting for the specific gravity of a ripe tomato of 0.95 (based upon water displacement weights I’ve recorded on >800 tomatoes of all sizes, shapes and maturity levels), this comes to 4.074 lbs.

Michael's Portuguese Monster (2.610 DT 2012) HT001 8-20-2014 water displacement A Michael's Portuguese Monster (2.610 DT 2012) HT001 8-20-2014 water displacement B

This gives me more confidence than estimates from either caliper (4.373) or tape (4.054) measurements and some real hope that I might finally bust through that 4 lb. barrier!  Tentatively scheduled for official and certified weighing on Monday, August 25th for submission to the GPC (Great Pumpkin Commonwealth).

Latest pics. 8-20.  Weigh-off scheduled for 8-25 at 9:00 a.m.  No significant cracks or wounds so hopefully it will last until then.

Michael's Portuguese Monster (2.610 DT 2012) HT001 8-21-2014 D rev Michael's Portuguese Monster (2.610 DT 2012) HT001 8-21-2014 C rev

Latest pics 8-22

Comparison with Delicious (3.012 DT 2014)(6.51 Meisner 2011):

Michael's Portuguese Monster (2.610 DT 2012) HT001 8-22-2014 D Michael's Portuguese Monster (2.610 DT 2012) HT001 8-22-2014 E Michael's Portuguese Monster (2.610 DT 2012) HT001 8-22-2014 F

It’s definitely wider in all three dimensions: 185.7 X 159.0 X 143.8 vs. 171.8 X 145.9 X 112.3 mm, particularly in height.  However, is it actually 33% heavier?  Hard to say from pictures.  The Delicious specimen is very solid and filled out, with minimal lobing or crevices.

Confirming that roots have grown into the compost, though only in modest numbers.  And red wigglers continue to thrive.  Final boost of nutrients added today, though with less than 3 days left and the tomato already ripe, they may not have much of an effect.

Michael's Portuguese Monster (2.610 DT 2012) HT001 8-22-2014 worms and roots C rev

Michael's Portuguese Monster (2.610 DT 2012) HT001 8-22-2014 worms and roots F

August 24th

Final pictures before harvesting for official weighing in the morning –

Michael's Portuguese Monster (2.610 DT 2012) HT001 8-23-2014 B rev Michael's Portuguese Monster (2.610 DT 2012) HT001 8-23-2014 A rev

Caliper measurements put it at 4.780 lbs.

Taped circumference measurements put it at 4.457 lbs.

Both of these are unrealistically high, as this specimen is riddled with crevices, bumps and gaps.  I was badly burned a couple of years ago projecting a weight that was almost 1 pound too high for a tomato with deep crevices, etc.  The best I can do is apply a Geometry Adjustment Factor (GAF) as a “cheat” to get a better estimate.  I’ve used GAF’s in my weight prediction formulas for tomatoes that are deeply lobed, flattened, or otherwise oddly shaped.  For this specimen I assign a GAF of 2 for lobing, bumps, etc.  For each GAF score I take off 5% from the projected weight, so 10% total.

Thus for a more realistic prediction of weight I’ll use taped CC’s and 10% off for GAF

4.457 X 0.90 = 4.011 lbs., or 4 lbs. 0.18 oz., or 1.820 kg.

Prediction for official weight:  4.011 lbs.

= = = = = =

August 25, 2014

NEW UTAH STATE RECORD

3.754 lbs.

Michael’s Portuguese Monster (3.754 DT 2014)(2.610 DT 2012)

Off by 1/4 pound.  Better estimate than last time, but still disappointing.  Got a long ways to go to really get into the BIG League.

Weighed in at the Utah Division of Weights and Measures, witnessed and certified by officials with responsibility for certifying all commercials scales in the state.

Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) B

Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) E rev

Thurber, Tomato, Michael's Portuguese Monster (3.754 DT 2014)(2.602 DT 2012) GPC Entry Form

Small kitchen scales are very close:

Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) ZS rev

Other views:

Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) ZN rev Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) ZJ rev Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) ZI rev Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) ZH rev

Size perspective:

Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) ZOrev

Relative density (compared to water) calculated at 0.900:

Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) I Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) K

Weights of two wet but empty buckets above; demonstration of immersion and water displacement calculation below:

Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) S

Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) Y

Larger bucket weighed 5.172 lbs. with displaced water.  Empty it was 1.000 lb.  Therefore 4.172 lbs. of water was displaced.  3.754/4.172 = 0.900, which is the density relative to water.  Though there is a modest variance, I expected (or at least hoped) this tomato to be closer to the average density of large ripe tomatoes which is 0.95, based on similar calculations from > 800 tomatoes over the years.  If the density had been 0.95, this one would have weighed 3.962 lbs. with this volume of water displaced.

This tomato was at the peak of ripeness.  But all the rough handling compromised the integrity so I cut it up and 5 of us gorged ourselves on delicious tomato sandwiches.  Flavor score = 8.5 of 10 – a very nice, sweet and lively flavor – much better than one might expect from such a monster!

Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) ZUrev

Seeds are now fermenting and should be available within two weeks from:

DT SEEDS

Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) ZVrev

Here are charts showing a fairly stable growth rate after about 12 days.  Note that growth slowed minimally during the last week of ripening.  Many growers pick at first blush, but in my experience, the slight contraction in size only lasts for a day or two, then growth continues while ripening occurs, and ripe tomatoes are simply more dense than green ones.

Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) ZZB Michael's Portuguese Monster (3.754 DT 2014)(2.610 DT 2012) ZZA

Stay tuned – this vine is not finished yet – let’s see how it’s younger sibling grows now that this BIG one is out of the way!

A bit of media coverage in the local paper

Salt Lake Tribune – Utah’s Record Tomato

And on the Local NPR radio station

KUER – Record Tomato

 

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =

I finally got up the nerve to cull the growing 8X on the next truss down – the one with 30 sepals and profiled as the most promising megabloom on June 30th.  This one was growing at a modest pace and looked like it had HUGE potential, but I don’t see how it could ever catch up to the one above it and, in theory, it is taking resources away from the larger tomato.  So here it is, the hardest tomato I’ve ever had to cull:

Michael's Portuguese Monster (0.112 DT 2014)(2.610 DT 2012) E Michael's Portuguese Monster (0.112 DT 2014)(2.610 DT 2012) L Michael's Portuguese Monster (0.112 DT 2014)(2.610 DT 2012) C Michael's Portuguese Monster (0.112 DT 2014)(2.610 DT 2012) B

Note the very flattened pedicle. The scale’s platform is 5″ across.  Fully stretched, sepals span 6-1/4″.  Weight was only 0.112 lb. after growing for about three weeks.

There are at least two other tomatoes that have started to grow from those megablooms profiled on June 30th, but they are growing even more slowly.

One other tomato growing at a very good pace is a 6X on a Big Zac (2.602 DT 2012) vine.  It weighs only about 0.2 lbs. and is just a few days along – we’ll see if it can keep up it’s rapid growth.

Glass Gem corn stalks are doing very well this year!  Planted on April 30th in the best soil in a raised bed in the backyard garden, first tassels were observed on July 3rd and stalks are in full pollination mode now.  Though perhaps planted too close together, tallest stalk now measures 10′ 3″ tall!

Glass Gem Corn Stalks 10'3in 7-25-2014 E rev

Parsnip tops also got very tall this year – 7’1″ :

Parsnip Seed Heads 7'1in 7-21-2014

As for the 516 tomato plants originally transplanted in Kanab, only 96 were alive and healthy as of July 18th.  More are dying every day, including hundreds of replacement plants.  Beet Leafhoppers are still ubiquitous.  It is very likely that 100% of the 516 original plants will be dead within a week, though there is a chance that a few varieties may show some resistance.  That would be useful information, but does not come close to compensating for the utter devastation of this year.  I don’t even want to think about the monetary losses…

Curly Top Virus is as deadly as any blight, but should be much easier to control, now  that I know what to expect:

Curly Top Virus Tulle Bag 7-15-2014 A

Those with mesh (tulle fabric) bags are doing fine, but unfortunately they outgrow these very fast.  Without bags:

Curly Top Virus Dead Tomato Plant 7-15-2014 D

Next year, If I can scrounge up the $, I plan to put shade cloth over the entire patch.  In theory, the beet leafhoppers only feed when it’s hot, sunny and dry.

Melons, squash and peppers, on the other hand are, for the most part, growing and producing very well:

Tomato and Melon Patch Kanab 7-17-2014 B

Here is an Ananasnaya melon on July 15th:

Melon, Ananasnaya 7-15-2014 A

And an Ultra Skorospelyi watermelon:

Watermelon, Ultra Skorospelyi 7-15-2014 C

I’ve been trying for weeks to make crosses among some of the large-fruited tomato varieties.  Every morning I go out to the tomato patch and attempt cross-pollination as best as I can.  My biggest challenge has been finding enough pollen to pollinate emasculated flowers.  So far, only 1 of about 40 attempted crosses has been successful.  I’ve considered various reasons for this difficulty.  I think I’ve settled on the major factor:

TEMPERATURE

We get some fairly hot weather around here this time of year.  On July 23rd the high was 103°F while the low that night was 73. The next morning pollen was very scarce – I just about wore out the electric toothbrush!  Then we got a break from the heat.  Yesterday the high was only 92 and the low was 64.  I collected plenty of pollen this morning – more than I’ve seen yet!

Maybe cross-pollination should wait until September when the weather is more favorable, but that is the busiest time of year with harvesting and seed saving!

 

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