The Tropical Fruit Forum

Tropical Fruit => Tropical Fruit Discussion => Topic started by: JoeReal on May 23, 2019, 05:17:17 PM

Title: Heat Tolerance of Achachairu and mangosteen
Post by: JoeReal on May 23, 2019, 05:17:17 PM
What's the heat tolerance of Achachairu? I plan to bring my potted Achachairu outside in 50% shade after the frosts are over but our summer temps can go over the century mark for weeks at a time, sometimes hitting 120F. What has been the experience of people growing these? Or at least some literature that talks about the temperature tolerance.

I've read somewhere that Mangosteen can't tolerate heat above 100F, so I'd like to know if anyone can confirm this.


Title: Re: Heat Tolerance of Achachairu and mangosteen
Post by: brian on May 23, 2019, 09:58:06 PM
I have two garcinia seedlings (~10in tall) in my greenhouse, with no shade.  My temp sensors read ~110F whenever it is bright and sunny outside.  They look happy, but I've only had them a month or two.

I'm not sure if northern greenhouse temps are meaningful compared to outside temps in hot climates.
Title: Re: Heat Tolerance of Achachairu and mangosteen
Post by: JoeReal on May 24, 2019, 11:45:05 AM
I have two garcinia seedlings (~10in tall) in my greenhouse, with no shade.  My temp sensors read ~110F whenever it is bright and sunny outside.  They look happy, but I've only had them a month or two.

I'm not sure if northern greenhouse temps are meaningful compared to outside temps in hot climates.

I ran across a very interesting study that shows the achachairu seedlings, and perhaps the mangosteen too will really thrive and grow fastest with 50% sunshine shade. Full sunlight freezes their growth.



http://www.scielo.br/scielo.php?pid=S1983-40632018000400407&script=sci_arttext (http://www.scielo.br/scielo.php?pid=S1983-40632018000400407&script=sci_arttext)
ABSTRACT

The successful establishment of a Garcinia humilis orchard depends on planting high-quality seedlings. This study aimed to evaluate the effects of the shading level (0 %, 18 % and 50 %) and substrate composition on the formation of G. humilis seedlings. Four substrates (S) were evaluated combining different proportions (v:v) of soil (SO), cattle manure (CM), commercial substrate (CS), sand (SA) and fine grain vermiculite (FV): S1 = 0 % SO + 45 % CM + 20 % CS + 20 % SA + 15 % FV; S2 = 15 % SO + 30 % CM + 20 % CS + 20 % SA + 15 % FV; S3 = 30 % SO + 15 % CM + 20 % CS + 20 % SA + 15 % FV; S4 = 45 % SO + 0 % CM + 20 % CS + 20 % SA + 15 % FV. The experiment was conducted in a completely randomized design in each environment, being the environments compared by a joint analysis. The G. humilis seedlings with the highest quality were obtained in the environment with a 50 % shading screen. G. humilis seedlings do not grow when exposed to full sunlight and, therefore, the seedling production of this species with direct solar radiation, without some shading level, should not be recommended. Different combinations from the mixture of soil, cattle manure, commercial substrate, sand and fine grain vermiculite may be used in the formulation of substrates for G. humilis seedlings.
Title: Re: Heat Tolerance of Achachairu and mangosteen
Post by: brian on May 24, 2019, 11:56:45 AM
Thank you for this, Joe.  I right now am moving my garcinias to sit under larger trees. 
Title: Re: Heat Tolerance of Achachairu and mangosteen
Post by: brian on May 24, 2019, 12:01:16 PM
(https://i.imgur.com/15JuGQO.jpg)
Title: Re: Heat Tolerance of Achachairu and mangosteen
Post by: mikemap on May 25, 2019, 03:55:50 AM
Comparing the study cited to my local conditions in Hawaii, I see the study was done in Cassilāndia, which is about 19° from equator, about the same as here, and the temperatures measured during the study were mostly around 26°C, also about the same as here. In other words, a mild climate that rarely gets hot. So the study seems to offer no insight on the above questions of extreme heat tolerance.

The question remains how the sun tolerance changes with age of plant, since the study tested tiny plants up to 201 days of age, and all the anecdotal evidence suggests achacha (and mangosteen and other Garcinia) adapt well to full sun at some point. My friend who has gotten 2 generations of fruiting achacha here has grown them in full sun their entire lives, with fruit after 6 or 7 years from seed. He often talks about his belief that they like full sun, but it seems based on speculation. Maybe we can do a little better with more shade, but at least it's not a critical issue in practice.

Perhaps as the plant ages, its lower canopy gets shade from its upper canopy?
Title: Re: Heat Tolerance of Achachairu and mangosteen
Post by: Felipe on May 25, 2019, 01:42:38 PM
In general tropical plants can take a lot of heat, BUT only if they get water and humidity is high!
If you have young plans in pots I would keep them in shade in make sure the soil keeps wet..