Three days ago my largest tomato (growing from a Big Zac (3.94 Pennington 2010)(7.18 Harp 2009)) started to exhibit a distinctive deceleration of growth – from about 0.1 lbs./day to about 0.03 lbs./day. At 57 days since fruit set – along with cooling temperatures and shortening days – this slow-down is not surprising.
Out of curiosity, I got the crazy idea that it might be interesting to see if I could predict the final weight of this tomato, probably at least ten days before harvest. This is new territory, as I really don’t have much data upon which to base such a prediction. So this barely qualifies as an educated guess.
Here are some factors:
1. Using taped circumferences and the formula I’ve been working on (see previous posts), this one now measures to 4.35 lb. if it were ripe.
2. Based upon extrapolation from graphs, I predict growth will stop completely in about 6 days, at which time measurements should put it at around 4.52 lb. It will take another week or so to ripen up after that, thus increasing in density without measurable increase in girth.
3. Perhaps the wildest of all guessing, I’ll take off 8% for quite pronounced lobing. This puts the predicted final weight at:
To be honest, it doesn’t look like it will be even close to 4 lbs.; 3.5 maybe. We’ll see in a couple of weeks. I may have to harvest it earlier if we get hard frost. Here’s the latest pic:
Not having the heart two remove fast-growing tomatoes, I’ve left two much younger tomatoes growing on this vine also. They both weigh close to 1.5 lb. and are gaining about 0.3 lb. per day. This plant was pruned to two main stems and these two are growing on separate stems. Latest pics:
Interestingly, the 4-pounder is growing on a sucker – one of those that got away from me and I didn’t have the discipline to cut it off after discovering a nice-looking megabloom developing back in early August.
Additionally, I harvested a 2.482 lb. tomato off this vine on 9-10-2012 :
I picked this one while it was still growing at a decent rate in an attempt to divert plant resources to the then 2-week-old fruit that looked and was growing as if it had real potential to get big. For comparison, at 26 days after fruit set, the larger tomato (first one pictured in this post) measured to 1.36 lb., while this smaller one (last one pictured) measured to 0.94 lb.