Message Board - BigPumpkins.com

Ely Mn

during the day or night?

7/31/2014 8:05:05 AM

pizzapete

Hamilton Nj

ive noticed with all my veggies they all grow more with the moon light!!!! exspecially tomatos and cukes!!!

7/31/2014 8:22:39 AM

pizzapete

Hamilton Nj

ive noticed with all my veggies they all grow more with the moon light!!!! exspecially tomatos and cukes!!!

7/31/2014 8:22:39 AM

PA_J

Allentown, PA

Tomatoes grow best when the daytime temperature is between 65 and 85 degrees Fahrenheit. tomatoes stop growing above 95 degrees and will slow their growth to almost zero the cooler the temperatures are overnight.

7/31/2014 11:13:42 AM

East Carbon, Utah

With very promising tomatoes, I measure diameters with precision vernier calipers. In most cases, for the widest diameter at least, these can detect a change in diameter of 0.2 mm (0.008 in.).

I've had the same question and on several occasions have measured tomatoes at various times of the day and night. I've tried correlating growth rates with air temperature and cloudy vs. sunny days; to determine whether a good dose of compost tea results in a detectable increase of growth rate; etc.

Briefly, here are some observations:

• From about 16 days on, it seems that a given fruit is set on a course of growth. For the most part, it seems there is little I can do to change the rate of growth after that point.

• Water is an exception. Several times I've noted that if soil is getting on the dry side, a good dose of water does indeed lead to a growth surge.

• Normally I measure in the evening. For those times when I've measured in the morning as well, or even in the middle of the day or night, I have not been able to detect any difference in growth rates. Water and minerals are transported to the tomato primarily through xylem tissue, that is from the roots up. This transport occurs day and night, sunlight or overcast, at a fairly steady rate. Since a ripe tomato is about 94% water by weight, it might be very difficult to detect diurnal variations in weight gain resulting solely from the products of photosynthesis (i.e., carbohydrates).

• Once growth has set in, I have recorded steady growth rates, even at 100° plus. Though growth slows significantly when temps are in the 50's, and especially in the 30's and 40's, there is still some growth.

• No noticeable response to fertilizers, though response might be gradual and delayed by several days and thus undetectable with this methodology.

• High temperatures cause tomatoes to ripen quickly, while in cool weather, tomatoes just hang in there, green, growing

7/31/2014 8:23:04 PM

East Carbon, Utah

This goes way beyond the question, but hopefully this will be of interest to some.

My largest tomato to date, Big Zac (3.486 DT 2012) set fruit on August 26th and was harvested on December 6th.

I've partitioned the growth of this one into four phases:

1. Establishment - Day 1-15, geometry and growth rate establishing; tomato weight about 0.36 lbs. at day 16.

2. Rapid Growth - Day 16-61, quite steady, almost predictable weight gain of 0.058 lb. per day, nothing seemed to change growth rate; about 2.64 lbs. gained.

** Light frost event, Oct. 26th **

3. Slow Growth - Day 62-82, sudden switch to much slower growth of about 0.016 lb. per day, as if plant roots and stems were damaged by the frost, though top of plant was protected; about 0.34 lb. gained.

** Intermittent light frosts, then first hard freeze on Nov. 16th **

4. Wishful thinking phase - 3+ more weeks on the vine, with protection from frost and supplemental lights, with almost no growth. Tomato finally picked, partially ripe, with fungus started to invade.

These phases probably would not apply to a tomato grown during the warmer months of summers.

Obviously these are not definitive results: a replicated study with controls, large sample sizes, covariates taken into account, etc. would be needed. But these and similar observations suggest some intriguing insight into the physiology of growing giant tomatoes.

7/31/2014 8:23:24 PM

Porkchop

Central NY

Day

7/31/2014 8:34:43 PM

PA_J

Allentown, PA

Extremely interesting Dale. I thank you much for posting that information.

7/31/2014 9:29:53 PM

Ely Mn

thanks for all the replies!
the reason im asking is its been great temps during the day
but high 40's at night.maybe thats not such a bad thing.
might keep it from ripening to quick?

7/31/2014 9:36:54 PM

Muddy Waters

mine grow more in the daytime.very little night growth

7/31/2014 9:51:36 PM

East Carbon, Utah

Ok, you've piqued my interest!

So last night at 7:00 p.m. the widest diameter (D1) on my fastest growing tomato was 146.1 mm. At 7:00 a.m. this morning it was 148.9 mm.

If I can remember, I'll try to post a few more measurements over the next couple of days.

As you (Master P and PA_J) indicate, however, night time temps in the 40's would almost certainly slow down growth. Here in the high desert (Salt Lake Valley) this time of year, low temps are nearly always in the 60-80° range. So one would not expect slower growth at night.

Let's see, it's 63° out there now, and the NWS data shows a 58-77° range for daily low temps for July 2014, the coolest July I recall in many years.

I realize than not everyone uses vernier calipers. My preference for using these over a tape measure comes (perhaps obviously?) from a science background: I cannot get consistent readings using a tape measure; I measure lots of tomatoes (calipers are faster); and with frequent measurements I'm concerned about damaging the fruits while measuring with a tape.

8/1/2014 9:31:47 AM

Marv.

On top of Brush Mountain, Pa.

I always thought most of the growth occurs at night. In Ohio you can hear the corn "popping" at night as it grows. In Pennsylvania some of the pumpkin growers swear they hear their pumpkins increasing in size at night. It seems that the cracks in pumpkins due to growth occur almost always during the night, not there when you go to bed but there in the morning.

8/1/2014 10:13:11 AM

Muddy Waters

Felix grew 1/8 last night at 61 degree low.I will tell you at darkthirty how much it grows today

8/1/2014 3:11:20 PM

Ely Mn

well the 48 degree temps didnt effect the growth of my maters
at all about 5\8 inch in less than 24 hours.around day 26

8/1/2014 4:23:51 PM

East Carbon, Utah

Ok, it's 85° and at 7:00 p.m. we have:
151.0 mm

So overnight, gain was 2.8 mm
During the day, gain was 2.1 mm

I also measured at 1:00 and got 149.5.

My thinking is that the warmer it is, the more evapotranspiration occurs from both the leaves and the fruit. So on very warm days, tomatoes can lose some water and perhaps even shrink a bit. Then in the cooler evening hours, water content is replenished.

8/1/2014 9:14:54 PM

Porkchop

Central NY

I say night

8/1/2014 9:18:48 PM

Ely Mn

thanks alot seamfaster!great info!

8/1/2014 9:40:22 PM

BillF

Buffalo, MN (Billsbigpumpkins@hotmail.com)

Having spent many years as test engineer one result is good but we need more before we can draw a good baseline. Then we need to test all the variables such as when the nights are warmer than the day, does the wind, rain, clouds, altitude etc. make a difference.

I know Porkchop has got it right or does he have it wrong?

8/1/2014 9:59:03 PM

Muddy Waters

She grew 1/8 today so its the same as last night.

8/1/2014 10:19:32 PM

Porkchop

Central NY

I change my answer to yes....

8/1/2014 10:37:45 PM

East Carbon, Utah

1:00 a.m. (now it's getting beyond obsessive), temperature is 71°, and widest diameter is:

151.8

So that's a gain of 0.8 mm over the past 6 hours

Agree with Bill - much bigger sample size and more variables to take into account before we can draw any firm conclusions.

8/2/2014 3:09:38 AM

East Carbon, Utah

7:00 a.m., 65°

152.1 mm

Perhaps something other than diurnal factors going on. Goal for this one is 245.4 mm - it won't get there at this rate!

8/2/2014 9:08:32 AM

East Carbon, Utah

1:00 p.m., 84°

153.0 mm

Gain of 0.9 mm in 6 hrs.

8/2/2014 3:09:54 PM

Muddy Waters

78 degrees today Felix is now 21 & 1/8 inch

8/2/2014 8:54:43 PM