BER, Understanding the Cause

amideutch · April 7, 2008

I've posted the link to this article in other threads but thought about posting it in it's entirety as everybody is gearing up to ready their EB's,containers,raised beds you name it for planting. Ami

Blossom End Rot in Tomatoes

Knowing how to avoid blossom end rot in tomatoes, a common problem for growers, can improve yield and quality.

Laurie Hodges, Extension Vegetable Specialist

Acknowledgment

Blossom end rot of tomatoes is a common problem. It occurs under conditions of high plant water stress and heavy fruit load. The first sign is a small, water-soaked area around the blossom end of the fruit that rapidly darkens and enlarges. As this lesion enlarges, it shrinks and the area becomes sunken and leather-like. This depressed area may become infected with secondary pathogens. Early fruits on the plant may have blossom end rot, while those that develop later are normal.

Blossom end rot is a symptom of calcium deficiency in the fruit. It can occur even when abundant calcium is in the soil and tissue tests show high levels of calcium in the plant. Poor calcium distribution in the plant results in low calcium levels where the lesion occurs.

Calcium, dissolved in water, moves through the plant in the vascular system from the roots to the leaves. Leaves are the primary sink for movement of water because of water loss through transpiration. Under high moisture stress, water containing calcium and other minerals moves rapidly to the leaves.

Fruit does not transpire as much as leaves and thus tends to be bypassed. This results in a localized calcium deficiency. This calcium deficiency in an area of rapid growth, the end of the fruit, causes cells to collapse and the sunken-lesion symptom of blossom end rot.

Blossom end rot may appear on some of the first fruit clusters on a plant, due to the combination of rapid plant growth with a large leaf area for water transpiration, water stress, and fruit enlargement. Even a temporary water stress during early fruit enlargement can cause blossom end rot because the fruits are the last to receive adequate calcium.

Calcium, unlike potassium or phosphorus, is not remobilized from the leaves to the fruits. Thus, foliar sprays of calcium won’t correct blossom end rot. Tomato fruits do not have openings in the epidermis (skin) where moisture can be lost or where calcium can enter the fruit from surface application, so direct application of calcium to fruit is ineffective.

Another cause of blossom end rot is over-fertilization, especially of nitrogen, which stimulates vegetative growth. Excessive vegetative growth increases the transpiration surface and further prevents calcium accumulation in the fruit. Tomato varieties with large amounts of foliage tend to be more susceptible to blossom end rot. Adjust the nitrogen rate for each cultivar to reduce blossom end rot. Avoid ammoniacal forms of nitrogen that compete with calcium during uptake from the soil.

Hot, windy conditions with low relative humidity can cause high transpiration rates ideal for inducing blossom end rot. Fluctuations in soil moisture during periods of rapid plant growth create moisture stress and limit calcium distribution to the fruit.

Preventing moisture stress is important to control blossom end rot, especially during fruit set and fruit enlargement. Plants require 1 acre-inch of water per week or more in sandy soil and during hot, windy weather.

Mulch to conserve moisture and adjust the nitrogen rate to the type of tomato being grown to avoid excessive vegetation. Use nitrogen in the form of potassium or calcium nitrate and avoid ammonium nitrate. Check soil pH and soil nutrient levels annually and adjust the pH to between 6.5 to 6.7 if necessary. Apply potassium, phosphorus, and magnesium as recommended because balancing these nutrients with calcium is also important in preventing blossom end rot. The primary factor, however, is maintaining uniformly adequate soil moisture throughout the season.
Acknowledgment

The author would like to acknowledge the work of Don Steinegger, Extension Horticulture Specialist, who was a contributor of the previous edition of this publication.

Visit the University of Nebraska–Lincoln Extension Publications Web site for more publications.

Index: Horticulture
Vegetables
Issued October 2007

celestina · April 7, 2008

Thanks Ami--very helpful!

**carolyn137** · April 7, 2008

Ami, I'm glad you posted that again.

I can't tell you for how many years I've been telling folks that Ca++ is not the major cause. So much research has been done in the last 20 years or so to prove that.

With BER being a multimillion dollar problem for the commercial farmer, not just for BER on Tomatoes, but also for peppers and cabbage and squash and more, if Ca++ were it, there would BE no more BER.

So often in books and magazines and on the internet folks just repeat what was said so many years ago and go on and on about Ca++ and eggshells, and Tums and whatnot.

I've concluded that it's going to take at least another generation before folks drop the Ca++ mantra.

There are only two situations I know of where Ca++ may play a role, and I'm too lazy to go back up and read that article now to see if these were mentioned, but one is when there is NO Ca++ in the soil which is exceedingly rare, and the other is when the soil is very acidic in which case Ca++ binds in the soil and isn't transported. But that can be solved by raising soil pH.

Ah, another situation is those growing tomatoes in containers, especially in high heat areas, where the extra water needed might flush out minerals, including Ca++, so adding some Ca++ in that situation might indeed help.

**mdvpc** · April 7, 2008

"Hot, windy conditions with low relative humidity can cause high transpiration rates ideal for inducing blossom end rot."

Describes my growing conditions exactly in the desert Southwest. But I rarely get ber.

amideutch · August 2, 2016

Been seeing more threads on BER problems as of late so I'm bumping this thread.

Ami

My Foot Smells · August 2, 2016

I got more BER this year than the past 10 years combined. I feed with TTF (previous TT) and amend with a rich organic compost topping each year. The weather has a lot to do with BER, probably with the scientific info you provide in this article.

However, if an article is going to discuss the cause(s) of BER, it should also mention prevention, if possible. Given the weather pattern and abuse this year with torrential rains, gale force winds, cool temps at the wrong time, triple digit heat, drought like conditions, and flash floods; don't know what really could be done by those affected.

Seems (i.e., no scientific proof) like most of my BER problems came when fruit set and then got hit with 3 weeks of cool temps where lows dipped back into the 50's in May. Then, SHAZAM!!! here comes the heat. However, the tomatoes that set later (p/ cool snap) were not affected to a large degree. Has me thinking that low temps might be more influential.

Maybe just toss a tums in the planting hole and hope for the best? j/k

b54red · August 3, 2016

Quote:

Originally Posted by My Foot Smells

I got more BER this year than the past 10 years combined. I feed with TTF (previous TT) and amend with a rich organic compost topping each year. The weather has a lot to do with BER, probably with the scientific info you provide in this article.

However, if an article is going to discuss the cause(s) of BER, it should also mention prevention, if possible. Given the weather pattern and abuse this year with torrential rains, gale force winds, cool temps at the wrong time, triple digit heat, drought like conditions, and flash floods; don't know what really could be done by those affected.

Seems (i.e., no scientific proof) like most of my BER problems came when fruit set and then got hit with 3 weeks of cool temps where lows dipped back into the 50's in May. Then, SHAZAM!!! here comes the heat. However, the tomatoes that set later (p/ cool snap) were not affected to a large degree. Has me thinking that low temps might be more influential.

Maybe just toss a tums in the planting hole and hope for the best? j/k

I haven't seen a case of BER since I started using TTF regularly about five years ago. By regularly I mean I feed the plants every week from the time they start blooming. Along with the very heavy mulch I use the plants rarely if ever get too dry and the TTF has adequate calcium for them. I used to get it much more often when I fed my plants much more sporadically and allowed them to dry out more often. I started using the TTF to get better fruit set but a side benefit has been healthier plants with no BER. I think those ups and downs with soil moisture really made a difference in the incidence of BER. I remember letting some of my beds get way too dry when the plants had plenty of fruit on them and then in the next few weeks I would find BER on those same plants. Since my raised beds drain well I have never had BER issues related to too much rain. I assume the stress caused by low soil moisture during hot windy days caused the BER. This has been a very dry season up til this week when we finally got an inch of rain but my regular watering and feeding have kept the soil under the mulch moist enough to prevent BER and even have some good fruit set despite the conditions.

Bill

Ricky Shaw · August 2, 2016

Tomato varieties with large amounts of foliage tend to be more susceptible to blossom end rot. - amideutch

What I'm hearing here, and what my garden is telling me is. Container growers should learn good pruning techniques, and lean to varieties with smaller foliage to fruit ratios.

amideutch · August 3, 2016

Quote:

Tomato varieties with large amounts of foliage tend to be more susceptible to blossom end rot. - amideutch

I have not experienced that. I have grown over 200 varieties in containers with no pruning and have experienced BER only twice and that was on 2 varieties of paste tomatoes which did not have excessive foliage.

Most times BER is caused by stress which can be caused by a number of reasons whether it be lack of water, nutrients, weather you name it.

Ami

**coronabarb** · September 9, 2016

Ami, can you post the link again to the article as I can't find it.

Cole_Robbie · September 9, 2016

My no-till experiment gave me the worst BER I have ever had this past summer. I put down loose soil over untilled ground, then drip line and plastic. It did not rain for almost six weeks in June. I ran the irrigation, but it wasn't enough to soak the ridge of dirt. I could feel it crunch like powder on the sides of the ridge. Every oblong cherry I tried got BER to the point of being a 100% loss. There were some I never even got a fruit to taste.

The one shining exception was Maglia Rosa. I did not get BER on a single fruit out of 50 row feet of plants. It would be really interesting to me to know exactly why. The differences in that variety that I can think of are that it is a short, bushy plant, and also a determinate. I'm a big fan of Fred Hempel's work as a breeder, but his other Artisan cherries, only the oblongs, got BER just as bad as anything else. None of my round cherry varieties had BER, nor any other varieties regardless of fruit size.

We know BER is about moisture consistency, but that doesn't explain the differences in the varieties that get it versus the ones that don't. I am guessing it is more specifically about moisture transport within the plant. Some varieties are just better at keeping their internal moisture consistent. I don't know the exact mechanism for that, but I can only guess it will be discovered at some point.

Scooty · September 9, 2016

http://extensionpublications.unl.edu.../pdf/g1752.pdf

**coronabarb** · September 9, 2016

Thank you so much, Scooty!

Cole, it is just exasperating.

**carolyn137** · September 9, 2016

You might try this link as well.

Mike Dunton of Victory Seeds asked me to write it.There may be a few minor changes I'd make,but BER,both internal and external,have always existed.

http://www.webgrower.com/information/carolyn_ber.html

Carolyn

jtjmartin · September 9, 2016

Quote:

Originally Posted by carolyn137

You might try this link as well.

Mike Dunton of Victory Seeds asked me to write it.There may be a few minor changes I'd make,but BER,both internal and external,have always existed.

http://www.webgrower.com/information/carolyn_ber.html

Carolyn

Carolyn:

Excellent article . . . but it will take me some time to give up my calcium!

I guess - like most things in life - there's no simple solution to cure a complex problem.

Jeff

April 7, 2008	#1
amideutch Tomatovillian™ Join Date: Feb 2006 Location: Germany 49°26"N 07°36"E Posts: 5,041	BER, Understanding the Cause I've posted the link to this article in other threads but thought about posting it in it's entirety as everybody is gearing up to ready their EB's,containers,raised beds you name it for planting. Ami Blossom End Rot in Tomatoes Knowing how to avoid blossom end rot in tomatoes, a common problem for growers, can improve yield and quality. Laurie Hodges, Extension Vegetable Specialist Acknowledgment Blossom end rot of tomatoes is a common problem. It occurs under conditions of high plant water stress and heavy fruit load. The first sign is a small, water-soaked area around the blossom end of the fruit that rapidly darkens and enlarges. As this lesion enlarges, it shrinks and the area becomes sunken and leather-like. This depressed area may become infected with secondary pathogens. Early fruits on the plant may have blossom end rot, while those that develop later are normal. Blossom end rot is a symptom of calcium deficiency in the fruit. It can occur even when abundant calcium is in the soil and tissue tests show high levels of calcium in the plant. Poor calcium distribution in the plant results in low calcium levels where the lesion occurs. Calcium, dissolved in water, moves through the plant in the vascular system from the roots to the leaves. Leaves are the primary sink for movement of water because of water loss through transpiration. Under high moisture stress, water containing calcium and other minerals moves rapidly to the leaves. Fruit does not transpire as much as leaves and thus tends to be bypassed. This results in a localized calcium deficiency. This calcium deficiency in an area of rapid growth, the end of the fruit, causes cells to collapse and the sunken-lesion symptom of blossom end rot. Blossom end rot may appear on some of the first fruit clusters on a plant, due to the combination of rapid plant growth with a large leaf area for water transpiration, water stress, and fruit enlargement. Even a temporary water stress during early fruit enlargement can cause blossom end rot because the fruits are the last to receive adequate calcium. Calcium, unlike potassium or phosphorus, is not remobilized from the leaves to the fruits. Thus, foliar sprays of calcium won’t correct blossom end rot. Tomato fruits do not have openings in the epidermis (skin) where moisture can be lost or where calcium can enter the fruit from surface application, so direct application of calcium to fruit is ineffective. Another cause of blossom end rot is over-fertilization, especially of nitrogen, which stimulates vegetative growth. Excessive vegetative growth increases the transpiration surface and further prevents calcium accumulation in the fruit. Tomato varieties with large amounts of foliage tend to be more susceptible to blossom end rot. Adjust the nitrogen rate for each cultivar to reduce blossom end rot. Avoid ammoniacal forms of nitrogen that compete with calcium during uptake from the soil. Hot, windy conditions with low relative humidity can cause high transpiration rates ideal for inducing blossom end rot. Fluctuations in soil moisture during periods of rapid plant growth create moisture stress and limit calcium distribution to the fruit. Preventing moisture stress is important to control blossom end rot, especially during fruit set and fruit enlargement. Plants require 1 acre-inch of water per week or more in sandy soil and during hot, windy weather. Mulch to conserve moisture and adjust the nitrogen rate to the type of tomato being grown to avoid excessive vegetation. Use nitrogen in the form of potassium or calcium nitrate and avoid ammonium nitrate. Check soil pH and soil nutrient levels annually and adjust the pH to between 6.5 to 6.7 if necessary. Apply potassium, phosphorus, and magnesium as recommended because balancing these nutrients with calcium is also important in preventing blossom end rot. The primary factor, however, is maintaining uniformly adequate soil moisture throughout the season. Acknowledgment The author would like to acknowledge the work of Don Steinegger, Extension Horticulture Specialist, who was a contributor of the previous edition of this publication. Visit the University of Nebraska–Lincoln Extension Publications Web site for more publications. Index: Horticulture Vegetables Issued October 2007 __________________ Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘...Holy Crap .....What a ride!'

April 7, 2008	#3
carolyn137 Moderator Emeritus Join Date: Jan 2006 Location: Upstate NY, zone 4b/5a Posts: 21,169	Ami, I'm glad you posted that again. I can't tell you for how many years I've been telling folks that Ca++ is not the major cause. So much research has been done in the last 20 years or so to prove that. With BER being a multimillion dollar problem for the commercial farmer, not just for BER on Tomatoes, but also for peppers and cabbage and squash and more, if Ca++ were it, there would BE no more BER. So often in books and magazines and on the internet folks just repeat what was said so many years ago and go on and on about Ca++ and eggshells, and Tums and whatnot. I've concluded that it's going to take at least another generation before folks drop the Ca++ mantra. There are only two situations I know of where Ca++ may play a role, and I'm too lazy to go back up and read that article now to see if these were mentioned, but one is when there is NO Ca++ in the soil which is exceedingly rare, and the other is when the soil is very acidic in which case Ca++ binds in the soil and isn't transported. But that can be solved by raising soil pH. Ah, another situation is those growing tomatoes in containers, especially in high heat areas, where the extra water needed might flush out minerals, including Ca++, so adding some Ca++ in that situation might indeed help. __________________ Carolyn

April 7, 2008	#4
mdvpc Tomatoville® Moderator Join Date: Jan 2006 Location: San Antonio, Texas Posts: 4,386	"Hot, windy conditions with low relative humidity can cause high transpiration rates ideal for inducing blossom end rot." Describes my growing conditions exactly in the desert Southwest. But I rarely get ber. __________________ Michael

August 2, 2016	#5
amideutch Tomatovillian™ Join Date: Feb 2006 Location: Germany 49°26"N 07°36"E Posts: 5,041	Been seeing more threads on BER problems as of late so I'm bumping this thread. Ami __________________ Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘...Holy Crap .....What a ride!'

August 2, 2016	#6
My Foot Smells Tomatovillian™ Join Date: Jun 2015 Location: Pulaski County, Arkansas Posts: 1,239	I got more BER this year than the past 10 years combined. I feed with TTF (previous TT) and amend with a rich organic compost topping each year. The weather has a lot to do with BER, probably with the scientific info you provide in this article. However, if an article is going to discuss the cause(s) of BER, it should also mention prevention, if possible. Given the weather pattern and abuse this year with torrential rains, gale force winds, cool temps at the wrong time, triple digit heat, drought like conditions, and flash floods; don't know what really could be done by those affected. Seems (i.e., no scientific proof) like most of my BER problems came when fruit set and then got hit with 3 weeks of cool temps where lows dipped back into the 50's in May. Then, SHAZAM!!! here comes the heat. However, the tomatoes that set later (p/ cool snap) were not affected to a large degree. Has me thinking that low temps might be more influential. Maybe just toss a tums in the planting hole and hope for the best? j/k Last edited by My Foot Smells; August 2, 2016 at 08:50 AM.

April 7, 2008	#2
celestina Tomatovillian™ Join Date: Mar 2007 Location: New Mexico Posts: 153	Thanks Ami--very helpful!

August 2, 2016	#8
Ricky Shaw Tomatovillian™ Join Date: Aug 2015 Location: Zone 6a Denver North Metro Posts: 1,910	Tomato varieties with large amounts of foliage tend to be more susceptible to blossom end rot. - amideutch What I'm hearing here, and what my garden is telling me is. Container growers should learn good pruning techniques, and lean to varieties with smaller foliage to fruit ratios.

September 9, 2016	#10
coronabarb Tomatoville® Recipe Keeper Join Date: Jan 2006 Location: Roseburg, Oregon - zone 7 Posts: 2,821	Ami, can you post the link again to the article as I can't find it. __________________ Corona~Barb Now an Oregon gal

September 9, 2016	#11
Cole_Robbie Tomatovillian™ Join Date: Jun 2012 Location: Illinois, zone 6 Posts: 8,407	My no-till experiment gave me the worst BER I have ever had this past summer. I put down loose soil over untilled ground, then drip line and plastic. It did not rain for almost six weeks in June. I ran the irrigation, but it wasn't enough to soak the ridge of dirt. I could feel it crunch like powder on the sides of the ridge. Every oblong cherry I tried got BER to the point of being a 100% loss. There were some I never even got a fruit to taste. The one shining exception was Maglia Rosa. I did not get BER on a single fruit out of 50 row feet of plants. It would be really interesting to me to know exactly why. The differences in that variety that I can think of are that it is a short, bushy plant, and also a determinate. I'm a big fan of Fred Hempel's work as a breeder, but his other Artisan cherries, only the oblongs, got BER just as bad as anything else. None of my round cherry varieties had BER, nor any other varieties regardless of fruit size. We know BER is about moisture consistency, but that doesn't explain the differences in the varieties that get it versus the ones that don't. I am guessing it is more specifically about moisture transport within the plant. Some varieties are just better at keeping their internal moisture consistent. I don't know the exact mechanism for that, but I can only guess it will be discovered at some point.

September 9, 2016	#12
Scooty Tomatovillian™ Join Date: Mar 2016 Location: Chicago-land & SO-cal Posts: 583	http://extensionpublications.unl.edu.../pdf/g1752.pdf