Degree-Day

[Pancrazio]

An interesting question for those who lives in a place where plants need to be kept indoor during winter is: "Will my plant fruit here?"
Usually we assume that if a plant can be grown outside without a cover, or a very minimal one, it can fruit.
But some calculation can be done for those who a forced to use a pot, taking in account your climate data (average max and min temperatures for each month). So, if you have those data, even if you don't have a first hand experience of someone tring to grow something tropical in your zone, you can calculate if something can produce mature fruits where you live.
I found this extremly interesting and useful when i tried to understand if mangos were able to fruit here (if you are curious, i just have the bare minimun requirements).
Unluckly anyway, for mangos there is a great lack of datas. The most important one is the total value of degree-day, while the base temperature, if you lack more precise datas, can be assumed at 12C (54F).   
Anyway, for those interested, this is how this method works: It is called "Degree-Day".

http://www.freshplaza.com/news_detail.asp?id=56494

This site allows you to see the "degree day" for your specific location. Just choose "cooling" to see the accumulation ABOVE the base temperature (this tool was inteded for energy management):

http://www.degreedays.net

This study gives some insight on how it works for commercial orchards.

http://industry.mangoes.net.au/userfiles/file/FR605%20Heat%20sums%20to%20predict%20fruit%20maturity%20in%20Kensington%20Pride%20mangoes.pdf

If people keep track of the day of the flowring of their mangos (and the day when the fruits are ripe), over several years they can calculate the required degree-day for that cultivar.
I hope this useful for someone.

[fruitlovers]

Because a plant will grow does not mean it will fruit or fruit well. It's all in degrees: 1) Plant will not grow at all
2) Plant will grow but will not fruit at all
3) Plant will grow and fruit, but fruits very sparsely or very rarely.
4) Plant grows and fruits very well.
For commercial production you need number 4, but for hobby growing 2-4 is often enough.
Oscar

[Pancrazio]

I agree with you Oscar.
Too bad we often see clearly where a result like 4) can be achieved (commercial orchards are pretty evident) but the other points often are largely anecdotal.
I think would be interesting to have a way to discriminate if a place is where you can achieve 2) or 3) with a given plant. Because a dedicate grower often can do thing to let his plant grow wich are absurd from a commercial point of view.

[fruitlovers]

I agree with you Oscar.
Too bad we often see clearly where a result like 4) can be achieved (commercial orchards are pretty evident) but the other points often are largely anecdotal.
I think would be interesting to have a way to discriminate if a place is where you can achieve 2) or 3) with a given plant. Because a dedicate grower often can do thing to let his plant grow wich are absurd from a commercial point of view.

Right! Also sometimes a small change by practices of the grower can change a situation number 2 into a 3, or even a 3 into a 4, making commercial production possible in an area never possible before.
Oscar