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Citrus Trees
01-21-2006, 04:53 PM
The grapefruit is a sub-tropical citrus tree grown for its fruit, which are also known as grapefruit.

The evergreen tree is usually found at around 5-6 m tall, although it can reach 13-15 m. The leaves are dark green, long (up to 150 cm) and thin. It produces 5 cm white four-petalled flowers. The fruit is yellow-skinned, largely oblate and ranges in diameter from 10-15 cm and has an acidic yellow segmented pulp. The numerous cultivars include the white grapefruit and the red, of which the 1929 US Ruby Red (of the Redblush variety) has a patent. The fruit has only become popular from the late 19th century, before that it was only grown as an ornamental plant. The US quickly became a major producer of the fruit, with orchards in Florida and Texas. In Spanish the fruit is known as toronja or pomelo.

The fruit was discovered in the 1750s, probably in Barbados; currently the grapefruit is said to be one of the "Seven Wonders of Barbados" [1]. It had developed as a hybrid of the pomelo (Citrus maxima) with the sweet orange (Citrus sinensis), though it is rather closer to the first than the second. Further crosses have produced the tangelo (1905), the minneola (1931) and the sweetie (1984).

The grapefruit was known as the shaddock until the 1800s. Its current name alludes to clusters of the fruit on the tree. Botanically, it was not distinguished from the pomelo until the 1830s, when it was given the name Citrus paradisi. Its true origins were not determined until the 1950s. This led to the official name being altered to Citrus × paradisi.

Grapefruit can have a number of interactions with drugs, often increasing the effective potency of compounds. Grapefruit contains naringenin and bergamottin, which inhibit the cytochrome P450 isoform CYP3A4 in the liver. It is via inhibition of this enzyme that grapefruit increases the effects of buspirone (Buspar), caffeine, simvastatin, terfenadine, felodipine, nifedipine, verapamil, estradiol, midazolam, tacrolimus, dextromethorphan (significant only at recreational doses), benzodiazepines and cyclosporine A. This effect was responsible for a number of deaths due to overdosing on medication, which led to its discovery. Grapefruit seed extract is a strong antimicrobial with proven activity against bacteria and fungi. It also has antioxidant properties.

Grapefruit forms a core part of the "grapefruit diet", the theory being that the fruit's low glycemic index is able to help the body's metabolism burn fat.

xfahmix
02-26-2006, 02:47 PM
Grapefruit seed extract is a strong antimicrobial with proven activity against bacteria and fungi. It also has antioxidant properties.

Good thing about the citrus!!
Antioxidant properties- One hypothesis states that supplementation with high doses of multiple micronutrients including high dose dietary antioxidants (vitamins C and E, and carotenoids) may improve the efficacy of radiation therapy by increasing tumor response and decreasing some of its toxicity on normal cells.

SxDxMxF
02-28-2006, 06:28 AM
Im not really a big fan of grapefruit. I dont know why, but the taste just never appealed to me. Do you know any good desserts that have grapefruit in em? Maybe I just havent tried the right stuff yet...

chrysalis
03-01-2006, 06:25 PM
A hybrid of the pomelo and orange, eh? I wonder how a fruit with very little distinctive taste could mix with a super-tasty sweet fruit and produce one of the bitterest things in the natural world! That said, I have to say that I enjoy the scent of grapefruits.

SxDxMxF
03-03-2006, 06:00 AM
A hybrid of the pomelo and orange, eh? I wonder how a fruit with very little distinctive taste could mix with a super-tasty sweet fruit and produce one of the bitterest things in the natural world! That said, I have to say that I enjoy the scent of grapefruits.

I too love the scent (as I do with most other citrus fruit) but the taste is what gets me...I can never finish a whole grapefruit, and grapefruit juice is just as bad, in my opinion. I would still like to grow some, though.

Citrus_canuck
03-03-2006, 06:21 AM
Mmmm I just love grapefruit. I could eat them non stop. Actually one of my favorite foods. no sugar and just eat em like an orange. mmmm. Never found one to be bitter or unplesant and I've eaten may many varieties

chrysalis
03-03-2006, 05:29 PM
You are kidding! I have never been able to pull off even ONE whole one in my life, with or without sugar! I just eat one piece and then it is so bad that I can't continue! I like pink grapefruit soda, but I think that's just grapefruit extract - probably artificial - and doesn't count as a citrus beverage

Citrus_canuck
03-03-2006, 07:51 PM
you must be buyingh awful grapefruits then! I just absolutly love them. ther fruit, the juice.. but I draw the line at the pop. thats just nasty

theodore
03-11-2006, 03:00 AM
The grapefruit was at one time called the 'forbidden fruit' and is believed to be of Caribbean origin. Grapefruit trees reach a height of between 22 and 30 feet at maturity. Leaves are 3 to 5 inches long, pointed at the tips with a rounded base. Flowers are white. The leaves are evergreen, living for as long as two years. The grapefruit itself is actually classified as a berry (hesperidium). Grapefruit at maturity are bright yellow with a thick peel with white, pale yellow, pink or red flesh. Seed content depends upon the variety ranging from an average of 50 to 60 seeds in a 'Duncan' or a 'Foster' to almost no seeds in a seedless variety like a 'Marsh' or a 'Star Ruby'.

azlawrence
03-26-2006, 08:50 PM
My grapefruit tree is almost 40 years old. It has been a wonderful source of good eating for our household. It has watered, fertilized and pruned along the way, but the yield seems to be tapering off. Is this likely a function of age? How long is it expected to bear fruit?

Citrus Trees
03-28-2006, 03:39 AM
hmm interesting...Have you had cold spells recently? What kind of fertilizer are you using and how often do you apply? I found some Care information which might be useful...


MATURE TREE CARE

Watering should be slow and thorough; probably every couple of weeks would suffice in any but the very sandy soils. Nutrition should continue at about one cup of ammonium sulfate per year of tree age annually in split applications in February, May and September, i.e. a 6-year-old tree should receive about six cups of 21-0-0 for the year. Adjust the rate for other fertilizers based upon the relative nitrogen content.

Lawngrass should be kept back about a foot from the canopy of the tree. Other than cold damage, no pruning should be necessary, as the grapefruit tree will develop its natural shape without pruning. While mulching is not recommended for citrus trees, if you must mulch, keep the mulch at least one foot away from the tree trunk.


PRODUCTION, MATURITY AND USE

Budded grapefruit trees, if properly established and grown, should bear in the third season after transplanting. Any fruit that sets in the first and second years should be removed in order to direct all of the young tree's energy into growth. The first production could easily exceed 25 pounds per tree, which should increase to some 250 pounds or more by the tenth season.

Generally, grapefruit does not 'ripen" in the normal sense of the word, rather, it matures to good eating quality. Texas grapefruit will usually achieve legal maturity in mid-to-late October, although the peel color will likely still be quite green (plus the red blushing of red-fleshed varieties). Natural degreening occurs gradually through the next couple of months. The longer the fruit remains on tree, the larger it becomes and the sweeter it becomes. Grapefruit holds very well on the tree, so fruit can be harvested as needed from late October through May.