Cross pollination between citrus trees will not result in the F1 fruit being a cross. You'll still have navel oranges, and if there are hybrids, they will be in the seeds, shambu. What I think you're seeing is fruit being born on rootstock branches. Can you take a good look at your tree, and see where these branches producing this fruit emanate from? If the branches are coming out from below the graft line, this is rootstock. You'll want to remove those branches, so the rootstock does not overtake your scion cultivar (the navel orange cultivar that is grafted to the rootstock). Please take some photos of your tree and see if you can photograph the trunk where the graft line is for us. Try to ID the branches (tie a ribbon close to the trunk on the branches that are producing these sour fruits). Pretty sure this is what you've got going on with your navel orange tree.

Patty S.

I agree with patty. This definitely sounds like fruit from the rootstock. Are the branches that these fruit are on have different shapes leaves? That would be a good indication, although that's not always easy to tell. Try to identify the graft and take a picture of the trunk.

Kristopher

Thanks for the information. I will take pictures of the trunk and the tree and will upload tonight. BTW, if this is the issue with rootstock fruit how do I fix this.

Cut off the branches at the trunk (just above the branch collar) at the trunk.

Patty S.

The dark branch is good orange

good orange

BTW the leaves of good orange or bigger and broader. The sour orange are small

trifoliate leaf in the upper right corner. sweet orange leaves in the bottom right corner.

if the tri leaves are coming off that large light colored trunk, then it is the root stock taking over. the smaller darker branches looks like its almost fully enveloped by the lighter-colored, thicker trunk.

you could probably cut the thick trunk at a 45' angle and pluck off any suckers that try to grow and maybe have a chance for the sweet orange to take over.

It looks pretty far gone. It must have been a couple years at least since the rootstock suckered.

I would consider topworking the main rootstock trunk with a desired variety instead of cutting it totally off. Reason I would consider that is it appears the rootstock may have taken over to the extent it is collaring off the remaining orange branches. Whatever you do, it is going to take some time, probably a couple years, to get the tree back into good productive shape.

Wow, you have some serious rootstock growth. As houston has mentioned, anything with trifoliate leaves (leaves of three), are clearly coming from your rootstock. Carefully cut those branches off, about 1/2" above where they come out of the trunk. Be sure to get them all. I would carefully identify all the rootstock branches (with trifoliate leaves) first, tie a ribbon on each so you know for sure, then make your cuts. You will have to stay on this, now, as those old branches will try to send out new growth if you can't get them trimmed right down to the trunk. Continue rubbing off any new growth, don't let branches get any bigger than a nub from below the graft line. Move your dripper out to the edge of the canopy, too, you have it against the trunk. The feeder roots for your tree are at the edge of the canopy (drip line). With a mature tree, you'll want four drips at 12 3 6 and 9, if you're using such small emitters as I see in your photo.

Patty S.

Thanks all for your help. This is the first year of fruit so I was not sure of the problem until the fruits are ripen. After reading your comments the only option is to cut the light colored trunk, this will bring the whole tree down. I dont feel good to cut the whole tree but I see have no choice and wait for couple of years. BTW, the good orange was sold to be as Navel Orange but it has a very thin skin and if the fruit is too ripe it hard to peel the skin. What is the Orange variety?

Question : Where do I exactly cut the tree and what is the best time to cut the tree. Do I have to cover the cut portion with some time so it does not rot. I live in Houston, TX

Once again appreciate your valuable knowledge.

i've got a N33 navel, just ate the one fruit i had this year last night, it was a much thinner skin than the grocery store navels. it had a few large seeds, small navel, sweet, and almost no acidity.

i would wait till March to cut it. it starts getting warm around the 3rd week of Feb, so i would fertilize it around that time, and cut during the 1st or 2nd week of March. it should start flushing out around March.

If it were my tree, I would just take it out and replace it with a new tree of 2-3 years.

I'm with johnmerr.

Cut that one out and get a new tree that has a better chance.

Shambu, you can't cut the whole tree down. If you do, you'll end up with ALL rootstock, and NO scion. Or, just some rather weak scion branches. Also, just a note - your tree is planted too deeply. It looks like your graft line is either right at the soil line, or possibly below. When you plant a citrus tree, you'll want to make sure the graft line is well above the soil line, to discourage the rootstock from sending up shoots. If that lighter, larger trunk is the part of the tree emanating from the rootstock, and the vast majority of the tree is rootstock, I agree with John. It's time to pull out the tree, and replace it.

Patty S.

I planted a small 3 gal tree 8yrs ago so over a this period yearly mulch and soil raised the bed level. Yes, the lighter larger part of the tree is having the bad oranges so it should be the rootstock. Anyway, how to identify the rootstock?

houstontexas123 - Do you know any place in Houston, TX who carries N33. I called couple of nurseries I normally go but they dont have it

You identify the rootstock by it being below the graft line. You must take care to plant your citrus high enough to account for adding mulch. You should not be piling mulch up against the trunk, ever, but only around the drip line. Think of planting your citrus tree on a small mound, with a nice well around the tree at the drip line. As your tree canopy extends, you'll need to extend the water well to match the drip line (edge of the canopy). You should always be able to see your graft line. This will discourage the root stock from sending out shoots, and will also protect the tree from foot rot. You should see a little root flange at the soil line. I think what has happened over the last 8 years, is the root stock has taken over your scion cultivar, either due to the scion perhaps being damaged from frost or freezes, as well as root stock sprouting up because your tree was planted too deeply. Just be sure to plant your tree high enough, and never pile mulch up against the trunk.

Patty S.

Thanks Patty. As I have a strong rootstock is it possible to graft on this with good orange variety or its easy to get rid of the tree and get a new one.

You can, if you know how to graft. That's always an option. But, unless you're an experienced citrus grafter, it would probably be easier to just replant. Citrus are just a bit harder to graft than, say, stone fruits are, but if you have grafted before, you could certainly undertake this. However, you'll get fruit a lot faster with a 2 to 5 year old nursery tree (5 to 15 gal tree), possibly even the same year, instead of waiting for your graft to mature enough to produce fruit.

Patty S.

he's gonna have to cut the main trunk down to where the navel graft is at. leaving only the navel branches. the root system is well established, but the scion is partially enveloped, not sure how well the tree will do in that condition. if you have room in your yard, get another tree, but plant it in a different spot, and see if you can get your current tree to divert all its energy into the navel scion.

i bought mine from RCW nursery at the corner of Beltway 8 and 249 for about $45. you'll have to go north on 249 and do a u-turn. their selection is kinda slim as they only get small shipments of each variety. http://www.rcwnurseries.com/rcw/

pretty much all the Houston Garden Centers (red & yellow umbrella logo) will have a wide assortment of citrus. you can find a decent tree for around $15-20. my dad has bought 4-5 in the past two years after he seen my citrus trees.

if you're near Pearland there's Joseph's nursery, they also have a nice selection of citrus. i bought my mango trees from them. http://www.themahanandi.org/2010/04/04/weekend-houston-josephs-nursery-pearland-tx/

there are two Cornelius nurseries, one off I-10 and Dairy Ashford, and one near the Galleria just north of Westheimer on Voss. not a huge selection but nice trees. http://www.calloways.com/stores-cornelius

houstontexas123 - Thanks for the info I will check with the nurseries.

Hello,

Yesterday I went to Houston Garden Center and picked up the only left Satsuma Mandarin 15 Gal for $39. I will plant in the ground in Spring. Hope it will bear some good fruit. In regards to the bad orange tree I will cut the rootstock and will see if the scion takes over.

Thanks all for your help

good luck

15 gal tree for $39 is a good deal, could we get a pic, we loves pics.

Although I respect everyones advice they gave you, starting over is not necessary. With the well established root system this tree would have all you need to do is prune, correctly, the rootstock branches out in early spring and you will have a vigorously growing citrus tree. I have done this many times, it works. It is nice to hear everyones point of view but they may not have enough experience to give you the best answer.

Rob, I think a few of us in this thread have some reasonable experience with citrus. I'm a Master Gardener, and have been growing citrus and other fruit trees for a while, now. I have over 50 different varieties of citrus, and about 60 total citrus trees on my property. I do citrus presentations for my CRFG chapter, have attended UC extension classes on citrus, and am always learning. I also have a background in science (Biology). John has a degree in Botany from UC Davis, and is developing a large commercial citrus business. Neither of us are experts, be we know a few things :-) Perhaps you have more education, experience, expertise than us. We would appreciate your comments.

The problem from what we can see with the photos, is the extent of the rootstock growth. That trunk emanating from the rootstock looks quite substantial. Cutting it off may cause a narrow crotch issue where the rootstock and scion are joined, which over time will eventually weaken the scion where it attaches to the rootstock, and may end up being the demise of the tree. Will the scion grow if the rootstock growth is removed? Most likely. But, will that provide a sound tree that can grow in the most healthy shape and manner? That's questionable. Again, just based on the few photos we have, this was several or our concerns. We really don't have enough photos to make the very best determination, and shambu is going to see if he can get the scion to recover and grow in a healthy manner, so time will tell.

Patty S.

The satusma mandrin plant. Thanks for all your advise.

nice tree Shambu.

just remember to plant it a few inches higher than ground level, b/c it will settle down a bit. give it a little mulch to keep out the weeds and grass.

its been a warm winter so far. shouldn't be a problem to plant it now.

Thanks houstontextas123. The guy at HGC told me I can plant now but not sure we might get late freeze as it did couple of years ago in houston.