Blossom End Rot (BER)

You know by now my Honeymoon tomatoes were afflicted by BER.  Looking online it seems its a physiological problem where the plant cannot take in sifficient calcium probably due to erratic watering.

Here's the question, probably for TMTT.  I'm on alkaline soil but not chalky, more flinty.  Would it be any use to incorporate some calcium carbonate into the soil or when watering? Or is it just a question of monitoring the water more carefully?

One year I grew San Marzano tomatoes in the GH and they were fantastic is all ways. The following year, I grew them again, same position in the GH, similar compost in the pots, and every tomato had BER whilst other varieties in the GH were healthy. Same compost, watered and fed on the same days. the only difference was the variety. Just saying!

I've only seen it on pot-grown beefsteaks and plums, probably because of erratic watering or nutrient imbalances, and I've not had any problems with BER since I started growing in the ground.

I doubt it's a lack of calcium in the soil, unless you frequently see signs of calcium deficiency in other types of plants.

Here's some good information from a university website (https://hort.extension.wisc.edu/articles...m-end-rot/):

"Blossom end rot is caused by a lack of calcium in the fruit. This lack of calcium may be due to low calcium levels in the soil. More often however, there is plenty of calcium in the soil, but its availability for uptake and transport to fruits is impaired. Drought stress, alternating soil moisture extremes, and damage to a plant’s roots all can inhibit calcium uptake, as can waterlogged or cold soils, and high concentrations of ammonium (NH4+), potassium (K+), and magnesium (Mg++) in soil. Movement of calcium within plants depends on active transpiration (i.e., loss of water through above-ground plant parts). Because leaves transpire more than fruits, calcium moves more easily into leaves where it remains. Calcium is not later redistributed from leaves to fruits. This preferential distribution of calcium to leaves can be made worse by over-fertilizing with nitrogen which promotes excessive production of leaves. In addition, high relative humidity OR low relative humidity in combination with hot, windy weather can limit transpiration, thus preventing calcium from reaching fruits."

"Avoid conditions where there is too much or too little water. Water evenly and mulch the soil to retain moisture during dry periods. Avoid practices that would damage roots (e.g., cultivating too near plants thereby cutting roots). Use nitrate (NO3–) rather than ammonium (NH4+) forms of nitrogen fertilizer. DO NOT over-fertilize. "

I've only seen it on pot-grown beefsteaks and plums, probably because of erratic watering or nutrient imbalances, and I've not had any problems with BER since I started growing in the ground.

I doubt it's a lack of calcium in the soil, unless you frequently see signs of calcium deficiency in other types of plants.

Here's some good information from a university website (https://hort.extension.wisc.edu/articles...m-end-rot/):

"Blossom end rot is caused by a lack of calcium in the fruit.  This lack of calcium may be due to low calcium levels in the soil.  More often however, there is plenty of calcium in the soil, but its availability for uptake and transport to fruits is impaired.  Drought stress, alternating soil moisture extremes, and damage to a plant’s roots all can inhibit calcium uptake, as can waterlogged or cold soils, and high concentrations of ammonium (NH4+), potassium (K+), and magnesium (Mg++) in soil.  Movement of calcium within plants depends on active transpiration (i.e., loss of water through above-ground plant parts).  Because leaves transpire more than fruits, calcium moves more easily into leaves where it remains.  Calcium is not later redistributed from leaves to fruits.  This preferential distribution of calcium to leaves can be made worse by over-fertilizing with nitrogen which promotes excessive production of leaves.  In addition, high relative humidity OR low relative humidity in combination with hot, windy weather can limit transpiration, thus preventing calcium from reaching fruits."

"Avoid conditions where there is too much or too little water.  Water evenly and mulch the soil to retain moisture during dry periods.  Avoid practices that would damage roots (e.g., cultivating too near plants thereby cutting roots).  Use nitrate (NO3–) rather than ammonium (NH4+) forms of nitrogen fertilizer.  DO NOT over-fertilize. "

Informative, I'll just see that watering is consistent and hope for the best next year.  I fed seedlings early on with miracle grow with a bit of epsom salts and after fruit set with bought tomato fertiliser. It will be interesting to see whether any further fruits suffer from it. Watch this space.

I was listening to a podcast discussing this recently (Davis Garden Show) and they said it has nothing to do with watering or feeding and everything to do with temperature. They said that if they're planted when the weather is too cool, they are unable to take up nutrients (calcium) correctly which then leads to BER.

Their only suggestion was to only plant when warm enough and remove any early fruit if you notice any signs as later fruit will be fine.

I thought it was an interesting point of view as it goes against conventional advice.

For the first time ever, I had BER on the Rambling Red tomatoes this year - just the first tomatoes, which I removed and the rest of the fruits have been OK.
This seems to support what you say, Garrett.

Interesting Garrett. I've had just 2 tomatoes affected so far one a big knobbly one and one orange banana which seem prone to it, both early. But lack of water is definitely a cause as well; the number of times I've been a bit late watering after a hot day and then lots of blossom dropping off as well as blossom end rot on developing tomatoes.

Guess what? I picked two lovely big Aurora tomatoes today and both had BER. I've been patiently waiting for them to ripen, the first big tomatoes of the year - what a disappointment.