It looks a little like an acorn but is an unripe cream sausage tomato, picked because I think it has blossom end rot.
I can’t see any other fruit with the same problem but the descriptions I’ve come across for blossom end rot are:
- Circular dark brown patch, that toughens and grows on the end of the tomato covering up to 1/3 to 1/2 of the fruit
- Shrunken, flattened area that turns dark brown to black and leathery in texture
All consistent with the look and feel of this tomato .
Blossom End Rot
A clumsy collection of words but a factual description. Down at the end of the tomato, where the flower once was, things have gone wrong. It’s not rotted as in soft, squidgy or mouldy but it is sunken, dark and leathery.
The cell walls of the fruit have collapsed due to the lack of calcium. (We use calcium for bones and skeletal structure; plants for cell membrane stability.)
There are a few possible causes. Calcium is soluble, transported round the plant in water, so most possible causes are water related.
- Not enough water to enable the plant to take in calcium
- What calcium the plant takes in gets to the leaves but not to the fruit
- Too much water and then too little water. Fluctuations in avaliable water can compromise a plant’s ability to take in calcium
- Too much fertilizer (high levels of potassium) can interfere with taking in calcium
- Low supplies of calcium in the soil or compost
Blossom end rot is not a virus and so doesn’t spread . However once fruit is structurally affected nothing can be done to right it.
I’ve come across recommendations for foliar calcium sprays but have also read this isn’t effective as calcium can’t move from leaves to developing fruit.
I’m not sure what might have triggered this. With my plants being in pots I’m guessing there will have been occasions on which it got too dry. For now I’m counting myself lucky it just seems to be the one.
It’s also made me curious about the role of calcium in plant nutrition so I’ll be taking a more detailed look in this week’s Saturday Swot Shop.
