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View Full Version : What low temperature does a banana fruit bunch stop growing?


Darkman
09-26-2011, 05:51 PM
I believe I read that when the daytime highs are at 55 degrees the banana will stop growing. Is it at that temperature that a fruit bunch would stop filling out and maturing?

sunfish
09-26-2011, 06:02 PM
I believe I read that when the daytime highs are at 55 degrees the banana will stop growing. Is it at that temperature that a fruit bunch would stop filling out and maturing?

I think it'smore to do with ground temp.

Darkman
09-26-2011, 06:19 PM
I think it'smore to do with ground temp.

Yes I'm sure that is true however I think there is a correlation between the two. I would think when the average day time highs are at a certain point most years the groud temp would be at a point that is consistent from year to year.

Nicolas Naranja
09-26-2011, 08:51 PM
The ground will stay much warmer than the air. That being said, I use 14C (57) as base temperature for calculating bunch readiness. It is probably different for different varieties but generally once I hit 1000C growing degree days my bunches are close to ready. Down here a November bunch will be ready in April, while a June Bunch will be ready in September. Of course winters are far more variable temperature wise so I have to keep a closer eye on things than in the summer.

Darkman
09-26-2011, 09:06 PM
The ground will stay much warmer than the air. That being said, I use 14C (57) as base temperature for calculating bunch readiness. It is probably different for different varieties but generally once I hit 1000C growing degree days my bunches are close to ready. Down here a November bunch will be ready in April, while a June Bunch will be ready in September. Of course winters are far more variable temperature wise so I have to keep a closer eye on things than in the summer.

Nicolas could you expand on that a bit?

And where are you measuring the temp?

As far as ground vs air I was under the impression that the ground temp will be warmer in the Winter BUT could be cooler in the Spring.


OK I may have answered my own questions.

I found this site

Heating & Cooling Degree Days - Free Worldwide Data Calculation (http://www.degreedays.net/)

that has a plug in equation and gathers data from local weather stations. Only thing is that it computes heating and cooling degree days. I think that is just a terminology issue and the results should be the same. If I understand right you use 14C as the low and every hour above that is and 1 degree day. When you reach 1000C degree days the fruit are near ready.

If that is correct I have had 1611.7 degree days. Does that sound correct? If I understand this right that means I have had 1611.7 hours at or above 14C since June 1st, 2011.

Nicolas Naranja
09-26-2011, 10:44 PM
That number sounds feasible to me. On average I accumulate 13.5GDD per day. Does that calculator have an upper threshold as well, because normally in agricultural degree days anything above 30C is marked as 30C because plants don't grow any faster above that temperature. Just be careful and don't mix up Fahrenheit degree days and celsius degree days. I actually use the temps at the nearest weather station to my farm (about 3 miles away) as a proxy. It's not exactly accurate but it's close enough.

venturabananas
09-27-2011, 01:27 AM
Wow Nick, that very clearly explains why you guys in FL get your bananas to grow so much faster than we do in CA: you get 4-5 times more degrees-days than I do in Southern California.

oakshadows
09-27-2011, 08:31 AM
Darkman, This info is good for many crops and thanks for posting it.

Nicolas Naranja
09-27-2011, 09:24 PM
Wow Nick, that very clearly explains why you guys in FL get your bananas to grow so much faster than we do in CA: you get 4-5 times more degrees-days than I do in Southern California.

Now in the winter we slow way down as our average lows dip into the low to mid 50s and our highs are in the mid 70s. I read a paper out of Australia that said when daylight gets below 12 hours it takes more degree days to cause flowering. To me it always seems that there is a dump of bunches in October and another one in April.