Banana Growing Degree Days
 

Does anyone know what the cardinal temperatures are for Bananas? I've read that the base is 14C and I am guessing that the top might be 30C, but I'm not sure.

P.S. I just realized that I made the common gringo mistake in calculating degree days for bananas. I used Fahrenheit.

Re: Banana Growing Degree Days
 

Base here in EC is 8C and we haven't found a top yet. Where Dole has its plantations routinely goes past 45C.

Re: Banana Growing Degree Days
 

are you talking about nanas inside the house or outside in the elements??? in my house i keep it between 68*(f) and 72*(f). and they seem to do well. however, i am doing an experiment.....half my nanas in the den with a 75 gallon aquarium and half in the livingroom with no source of humidity. the ones in the livingroom ive had to water 3 times in a week and the ones in the den ive watered 2 times in a week. so it varies on temp if you have the humidity.

Re: Banana Growing Degree Days
 

Where I am, there's no base temp cos of the weather. As far as top is concern in the lowlands, it's frying hot in Thailand to 150+F in the summer(full sun). In M'sia, about 120+F, again full sun in the dry months of Feb-Mar. I guess, these guys only worry about the cold. Seems no top temp here can knock them off except in extreme drought.

Re: Banana Growing Degree Days
 

I'm talking about in the elements, and I know that there is a top cardinal temperature for bananas because at some point on the thermometer respiration exceeds photosynthesis. I know that for Corn the top cardinal temp is 30C, and even though it lives above that temperature it does not accumulate GDD

Re: Banana Growing Degree Days
 

I would imagine it depends on the type, warm weather bananas probably thrive in hot conditions where as higher elevation bananas would not do nearly as well and may show some dye back. I would defer to Gabe when he checks in.

Re: Banana Growing Degree Days
 

living in Vegas i get both the bottom and top of the temp range. about 100 they slow down dramatically. they don't stop growing they just grow slowly. at the high point for this last year was 119 here in Vegas they were putting on a leaf about ever two weeks and are humidity is ruffly 15%. now in the house were they don't get that kind of temps but have allot lower light. they grow sorta in spurts a leaf a week for several weeks then nothing for a cuple if not three weeks. its been throw my observations that the rate of growth is more effected by UV then by temps. here in the south west we get the UV index every morning and the hotter it is the higher the UV. when the UV is over 10 they hardly grow at all unless there in shade. believe it or not my Bananas that are in shade grow faster then the ones in sun shaded light is vary high in blue light theres a thread on growe under lights i think you all should check out. so i know its sounds like if strade from the main topic but really light is more important them temps to a point.

Re: Banana Growing Degree Days
 

I worked for a plant physiologist a few years ago, and have a Master's in Agronomy, my expertise however is not bananas. However, plants in general respond to evaporative demand which is based on heat and humidity and if evaporative demand is high the stomata will close and the plants growth will cease. Another issue related to the UV light that you mentioned might very well have to do with photorespiration which is the wasteful evolution of carbon dioxide due to sunlight in C3 plants.

Re: Banana Growing Degree Days
 

thanks you for that info. i don't know much about plant chemistry/biology
could you brake that down a bit for us that don't understand what you mean by "wasteful evolution" also what are C3 plants?

Re: Banana Growing Degree Days
 

I'll let wikipedia do the job

C3
C3 carbon fixation - Wikipedia, the free encyclopedia

Photorespiration
Photorespiration - Wikipedia, the free encyclopedia

Take home message is that C3(Beans, Bananas, Rice) plants fix carbon for photosynthesis using a a 3-carbon sugar while C4(Sugarcane, Maize, Sorghum) plants use a 4-carbon sugar. Yet another type of carbon fixation would be CAM(Pineapple, Agave, Cactus) Photorespiration is bad because it uses carbon dioxide in a way that does not make the plant grow.

Re: Banana Growing Degree Days
 

That was enlightening, thanks! So by increasing CO2 to our banana plants, we are helping them grow by reducing photorespiration, which in turn causes more efficient photosynthesis by avoiding oxygen uptake.

So, other than putting our plants in an iron lung filled with CO@, what other things can we do to reduce photorespiration from occurring, if anything?

Re: Banana Growing Degree Days
 

Well, since it appears that photorespiration will occur in overly oxygen-rich environments, it would make sense to up the CO2 to the plants. I've done this for grapes by spraying them with a fire extinguisher, but I wouldn't risk that for my bananas.

However, it also only seems to be a problem for unaccustomed bananas in full sun in extremely hot and humid conditions (ie 80% humidity and low 50's), so for the most part, we don't need to be too too concerned about it. It also looks like bananas are C3 plants, for what that's worth, so they're theoretically more susceptible to photorespiration in full sun conditions. This said, they're not going to be photorespirating for a very sustained amount of time even in a heat snap. And I'd second whoever it was above that said that the tropical cultivars probably have a higher ceiling for PR than the high-altitude or cold-hardy ones.

edit - well, Scot, maybe you have to worry about it when it gets hot in your area.

I suppose that what I'm coming around to is that if your nanners are in shadier areas they'll be less suceptible to wasteful biological processes.

Re: Banana Growing Degree Days
 

A little bit of shade could help, if you can keep the plants well hydrated or perhaps near some body of water like a pool. I imagine an ideal place in the desert would be next to a pool under a screened in porch. I can only imagine how much water pools lose on a daily basis in Vegas.

Re: Banana Growing Degree Days
 

im sure i read in a Souther Navada water wasting pamplet that its meny hundreds of gal a week but i dont rember just how much

Re: Banana Growing Degree Days
 

Degree Days are the number of days with at least 8 hours at or above a median temperature a specific fruit cultivar takes to produce mature fruit after the blossoms have set fruit.

As with almost every kind of fruit, the degree days for banana depends on the group it is from and sometimes the specific strain. I have seen published reports of a 45 degree-day banana and a 180 degree-day banana. For navel oranges, most require 190 degree-days with a median temperature in the 70's (F), there is a 170 degree-day cultivar that tastes terrible, and also a 220 degree-day cultivar that tastes great and works very well in coastal environments.

Re: Banana Growing Degree Days
 

150+ degrees!?! I think your thermometer is in the sun.
Perhaps you are not aware that the highest officially recorded temperature ever on planet Earth is 136 degrees, and it wasn't in Asia...
(Libya, 1922)

Re: Banana Growing Degree Days
 

Could this be a case of warbal gloming?

Re: Banana Growing Degree Days
 

I would say that you are probably right.