I had two fruits on my Fremont Tangerine that I found split. They were quite tart but edible. Is anyone else growing this one? It is a cross of a Clementine and Ponkan and is supposed to hold well on the tree after ripening. Anyone else with splitting problems on Freemont?

Other members with splitting fruit have concluded that it is due to the excess rain their trees have been receiving recently that absorbed water faster than the skin can expand.

Yes I'm quite sure that is what caused it. Interestingly I have a Sunburst that is supposed to be susceptible to splitting and none did.

This is an update on Fremont splitting!

Again this year I am having the Fremont split. The only difference is more fruit and more fruit splitting. Rain has been bountiful with rain almost every day for the last month and a half. We (as of August 18, 2012) have had 54". Our average year is 65" and Issac may bring a good bit more next week!

Once again the Sunburst has had no splitting problems.

The seemingly spontaneous splitting that occurs in citrus fruits is discouraging. Splitting is an abiotic disorder, that is, it is a problem that cannot be attributed to any living organism, such as an insect or plant pathogen, but one that stems instead from environmental or cultural conditions. There is no chemical control for this physiological condition. The split usually starts at the stylar end of the fruit, which is the weakest point in the rind. Splits probably occur when water and sugar are transported from the roots of the tree to the ripening fruit, and the rind is unable to expand quickly enough to accommodate the added volume. The rind burst open under the pressure. Some citrus varieties, especially thin skinned ones, may be more likely to split than other varieties. Rinds that have been sunburned or otherwise damaged may be less elastic than normal and therefore more apt to split. Although the exact cause is unknown, fruit splitting is likely the result of stress to the tree. Splitting appears to be most closely related to extreme fluctuation in temperature, humidity, soil moisture, and possibly fertilizer levels, and the disorder is probably caused by a combination of these factors rather than by a single cause. For example, when hot weather is combined with high winds, the tree becomes drought stress and begins to take water from the
fruit, causing the fruit to soften causing it to crack. Young trees or dwarf
varieties with relatively small or shallow root systems, as well as trees
grown in very sandy or porous soils that do not retain moisture well, may be more susceptible. to fruit splitting. Eliminating the above probable causes may help in stopping or reducing the fruit from splitting. - Millet

I had thought last year that uneven watering may have been the issue but with the excessive amount we've had this year I can check that off the list and as you said it is probably a multi-issue that causes it.

Millet,

Do you think I should just trash this tree and plant another Ponkon or give it more time? Will it grow out of this as the root system further develops?

Millet wrote:

The seemingly spontaneous splitting that occurs in citrus fruits is discouraging. Splitting is an abiotic disorder, that is, it is a problem that cannot be attributed to any living organism, such as an insect or plant pathogen, but one that stems instead from environmental or cultural conditions. There is no chemical control for this physiological condition. The split usually starts at the stylar end of the fruit, which is the weakest point in the rind. Splits probably occur when water and sugar are transported from the roots of the tree to the ripening fruit, and the rind is unable to expand quickly enough to accommodate the added volume. The rind burst open under the pressure. Some citrus varieties, especially thin skinned ones, may be more likely to split than other varieties. Rinds that have been sunburned or otherwise damaged may be less elastic than normal and therefore more apt to split. Although the exact cause is unknown, fruit splitting is likely the result of stress to the tree. Splitting appears to be most closely related to extreme fluctuation in temperature, humidity, soil moisture, and possibly fertilizer levels, and the disorder is probably caused by a combination of these factors rather than by a single cause. For example, when hot weather is combined with high winds, the tree becomes drought stress and begins to take water from the fruit, causing the fruit to soften causing it to crack. Young trees or dwarf varieties with relatively small or shallow root systems, as well as trees grown in very sandy or porous soils that do not retain moisture well, may be more susceptible. to fruit splitting. Eliminating the above probable causes may help in stopping or reducing the fruit from splitting. - Millet

Trash a citrus tree? Isnt that blasphemy around here? My sunburst split a few also. Im sure itll be fine eventually

Charles not poor performers, just trees that I was no longer interested growing, or trees that I did not care for the taste. When your Fremont grows older and bigger, the splitting should stop, or at lest slow way back. If there is not a variety that you would much prefer to put in its place, then keep it. By the way, in the last few days I harvested my pomegranates (variety Wonderful). I picked 223 fruits, and only had 9 splits. I kept the soil moist and fertilized the tree twice during the season. Good luck with your grove. - Millet (I pray only 143 days left)