[Market-farming] blossom end rot

Bill Shoemaker wshoemak at illinois.edu
Thu Jun 18 17:18:20 EDT 2009

There are lots of "remedies" for blossom end rot (BER). Epsom salts is not one. In fact most won't work. BER is a physiological disorder related to calcium nutrition. However it can take place in soils high in calcium. It involves a failure of the plant to take up sufficient calcium to meet the needs of fast-developing tissue, usually the blossom ends of fruiting vegetables like tomatoes, peppers or watermelons. It can also happen to the tips of leaves in leafy crops, especially iceberg lettuce and sometimes cabbage, where its called tipburn.

The reason it happens is that the plant isn't pulling moisture in fast enough, so its always worse during drought. But it can happen at other times too. Sometimes its seen when soils are too wet and the air temperature is high. Calcium ions move passively with soil moisture through the plant to areas of need. If the water stream (transpiration) is compromised, the calcium flow breaks down and developing tissues have localized nutrient deficiencies. Calium builds cell walls, so those tissues break down, resulting in blossom end rot.

The remedy is almost always ensuring a steady supply of adequate moisture. Irrigation is good, but sometimes a good organic mulch layer is just as important, such as straw, grass clippings, leaves, etc. Its pretty rare that you can actually correct it with an application of something, though companies that market calcium nitrate often make that claim. 


---- Original message ----
>Date: Thu, 18 Jun 2009 16:43:04 -0400
>From: Richard Robinson <rrobinson at nasw.org>  
>Subject: Re: [Market-farming] blossom end rot  
>To: Market Farming <market-farming at lists.ibiblio.org>
>Someone on the high tunnels list mentioned epsom salts.
> --
> Richard Robinson
> http://www.nasw.org/users/rrobinson/
> On Thu, 18 Jun 2009 15:30:18 -0500, Marie Kamphefner wrote:
>> Regards to the list:
>> I can’t find the post now. What is the common household stuff somebody said
>> to put around the tomato plants to stop blossom end rot?
>> Marie in Missouri
>Market-farming mailing list
>Market-farming at lists.ibiblio.org
William H Shoemaker, UI-NRES
Sr Research Specialist, Food Crops
St Charles Horticulture Research Center
535 Randall Road  St Charles, IL  60174
630-584-7254; FAX-584-4610

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