Seeds require the right conditions in order to prosper. They require a good soil mix, adequate water and sun. Any deficit of these will cause die off, as will too much of these. As for the two sprouts from one seed this is not unusual. There are terms and explanations for it. As you learn you will become familiar with them. If you seperate the seedlings carefully & transplant them you can have two plants. This is especially true of rootstocks. Welcome to the forum.
The first seedling is infected with a fungus. This condition is called"damping off" and is contagious. There are fungicides that can prevent this disease, but on a small scale it may be impractical, as well as unsafe in a home environment. Keeping the soil a bit drier especially at the surface may be helpful.
Sunshine and airflow are quite helpful in preventing the issue, a little less effective at trying to stop it.
In regards to your double, or twin plant, this phenomenon is somewhat unique among plants, being found in many, but not all Citrus varieties, as well as mangos.
As David stated, if you choose to pursue Citrus growing and germination as a hobby, there will be a number of interesting facts about Citriculture.
Post by poncirusguy on May 20, 2020 20:29:47 GMT -5
When my seedling have at least 2 inches of root I will lift the plant to expose 1/2 inch of root. The roots never get damp off and damp off first starts at the soil's surface so the tender green stem is out of damp off reach.
The snail theory is discarded because I live on a sixth floor in the middle of the city, and I haven't seen one.
The soil is a mixture of humus, clay pellets and pearlite, drains very well and I don't overwater. It gets direct sunshine all morning and there is usually a breeze.
I think it's the damping off, since I germinated this plant in February in a container with coconut fiber next to a router to give it continuous heat. It was a disaster, out of about 20 seeds only that one was born, the rest eventually rotted and mould also appeared. From what I have read, damping off can appear during germination and appear later, so I think it is quite accurate.
Fortunately other seeds I left buried in a pot and have germinated now, in a couple of weeks they have equaled in size to the one in the picture, so they seem to be healthy.
Regarding the double roots/stems, I had read that some fruits (I think some citrus fruits too) have multiple embryos, being one of them a clone of the mother tree, but I don't know if it is the case of the yuzu. I have sprouted cherries, apples, pears and other fruits, and this is the first time it happens to me, so I did not know if it would be good to separate them as soon as possible, to eliminate one or to wait to separate them.
Excuse me if I don't express myself well, but my English is technical and I lack a lot of vocabulary about plants.
sanguinho, my personal preference would be to separate the 2 plants at time of repotting, if not sooner. The root systems on the 2 plants will become entangled, make a clean separation more challenging. The terminology used to describe clone seedlings vs non-clone seedlings is zygotic for the non-clone seedlings, there is almost never more than one per seed, zygotic twins are possible but extremely rare. In many cases there is no zygotic seedling, as the immature embryo aborted early in the process.
The clone seedlings are known as nucellar seedlings. There can be as few as one, there can be 5-6 per seed. Nucellar seedlings are highly desirable in propagation of rootstock, as they produce genetically uniform plants, all clones of each other.
Damping off becomes less of a threat once the plants toughen up and develop harder tissue. Soft, succulent newly emerging seedlings are very vulnerable, especially before they green up with chlorophyll.
Finally the seedling dried up, fortunately I have others that seem to be in good health.
However, I am worried about my poncirus trifoliata and sudachi, as they are barely growing. They were all grown at the same time and under the same conditions as the yuzu
These two sudachis, have not passed their first two leaves, and in the sudachi on the right you can see that the leaves have not hardened. It sprouted a week before the one on the left, if it weren't for the fact that I transplanted them myself I would say that they are not the same plant.
We've had daytime temperatures over 62ºF / 20ºC all month and last week 86ºF / 30ºC