Some of my pepper plants dropped loads of flowers last season, producing few, if any, pods. The local nursery suggested blossom end rot, and also suggested I apply some sort of "blossom-fruit set" spray. I know there is a myriad of reasons for flower drop, so how can I pinpoint whether blossom end rot is the culprit? Any other tell tale signs? Thanks.
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Blossom end rot...Signs?
- Thread starter Roguejim
- Start date
Brain Strain Pepper Head
Banned
Calcium serves several functions in plants, including cation-anion balance, transport processes of cell membranes and assisting with extension of primary root systems. For vegetable producers, calcium’s most important function during the crop fruiting stage is its role in cell wall/cell membrane stability. If Ca is deficient in developing fruits, an irreversible condition known as blossom-end rot (BER) will develop. Blossom-end rot occurs when cell wall calcium “concrete” is deficient during early fruit development, and results in cell wall membrane collapse and the appearance of dark, sunken pits at the blossom end of fruit. Many farmers and gardeners may treat this condition as a fruit disease; however, nutrient and water management regimes are the culprit. The purpose of this publication is to introduce the problem of BER and provide a guide to effectively diagnose and treat this problem.
Diagnosis Guide
Although no data exists to quantify how much annual economic impact blossom-end rot has on Georgia’s bell pepper and tomato industries, it is safe to say that significant loss of fruit occurs during the spring crop season, especially during hot, dry years. What is also unknown in the vegetable research realm is if a single cause leads to BER, or if (as past research indicates) multiple factors contribute to its occurrence. One fact that everyone can agree on is that when BER is first noticed in the field, prompt action is essential to halt further incidence. Four simple questions in the field will lead to a timely diagnosis and treatment of the problem:
Question 1. Is the problem disease- or nutrient-related?
Figure 1. Buckeye rot of tomato caused by Phytophthora. (Photo by D. Langston, UGA)
There are only a few common fruit disorders resembling BER that can lead to an incorrect diagnosis of the problem. Fruit anthracnose may occur on pepper and tomato fruit, but only on the side walls. The same is true for sunscald, which appears on pepper fruit sidewalls and is pale in color. Buckeye rot, caused by Phytophthora, and cucumber mosaic virus (CMV) also resemble BER, but these disorders occur more infrequently than anthracnose. Blossom-end rot is uniformly dark brown and black in color, and appears ONLY on either the lower fruit sidewall or the blossom end of smaller and developing fruit. Often, symptoms will occur as far as 1/3 to halfway up the fruit, but will NEVER start at the stem (calyx) end. Also, BER symptoms will tend to appear during the first fruit set as, early on, growers are unaware of the problem until it’s too late. If these symptoms all correspond, the fruit has BER.
Recommendation: If these conditions all hold true, proceed to Question #2.
2. Is calcium fertilization adequate?
Examine liming and gypsum application records, along with the current season’s pre-plant soil test reports. If pre-plant soil test Ca levels are in the medium (801 to 1,200 lbs. Ca/acre) or high range (>1,200 lbs. Ca/acre), it is assumed that soil Ca levels are sufficient for crop growth. This is even more true for soil pH ≥ 6.0, with supplemental gypsum or lime being applied pre-plant at levels of 500 to 1,000 lbs./acre or higher.
Recommendation: If these conditions exist, proceed to Question #3.
Equally important to soil test results is plant tissue analysis. For bell pepper, sufficient leaf tissue percent Ca content just prior to (or at) early bloom stage should be within the range of 1.0 to 2.5 percent. For tomatoes, percent Ca content prior to (or at) early bloom should be within the range of 1.25 to 3.20 percent. Tissue levels below these would point to a possible emerging Ca deficiency.
Recommendation: No specific recommendations exist for alleviating a low soil Ca level after planting. However, calcium nitrate (CaNO3) is a water soluble source of Ca and nitrogen (N) and is routinely injected in drip irrigation systems. Some research has begun on a relatively new material, calcium thiosulfate (CaS2O3), which also is available for drip injection systems. Injections of soluble Ca sources should begin at bloom and proceed until fruit is approximately golf ball-sized. This is believed to be the critical time when calcium must move into developing fruit to avoid onset of BER.
Figure 2. Blossom-end rot of tomato. (Photo by Joshua Mayfield)
Figure 3. Severe BER symptoms progress from the blossom to the stem (calyx) end of the fruit.
(Photo by Joshua Mayfield)
Although some people believe foliar sprays can correct Ca deficiency in developing fruits, research is very inconclusive on this issue. What is well known is that Ca only moves in the plant via the xylem and moves with the transpirational water flow from the roots, up the plant and into developing leaves. Calcium has no ability to flow from the leaves via the phloem to the developing fruit. In addition, once fruit has grown to golf ball size, the waxy outer layer has developed and is believed to be quite impermeable to water. Therefore, it is recommended that all Ca supplied to fruiting vegetables be applied via the irrigation water so as to maximize uptake by roots.
Recommendation: If liquid fertilizers are already being used, proceed to Question #3.
Question 3. Is nitrogen and potassium fertilization excessive?
Research has shown that Ca in soil solution competes with potassium (K), magnesium (Mg) and ammonium-nitrogen (NH4-N) for uptake in the plant. Although no established guidelines exist to determine what proportions of these nutrients in soil or plant tissue are appropriate, it is known that excessive shoot growth resulting from overfertilization of N and K during early bloom and fruiting stages is a major contributor to BER in developing fruit. Since Ca moves with the transpirational water flow, water is going to go to areas of new shoot growth that have the greatest transpirational demand. Calcium will therefore be deposited in the new shoot and leaf tissues that result from excess fertilization, and little will end up in developing fruit where it is needed most. At early bloom stage for bell pepper and tomato, leaf N and K analysis should both be within 4.0 to 6.0 percent. Levels higher than these may indicate excess fertilizer.
Recommendation: Cut rates of N and K if excessive top growth is occurring. Switch N source to CaNO3 or begin injections of CaS2O3 at bloom stage. If these steps are already being implemented, proceed to Question #4.
Figure 4. Sunscald (or sunburn) on pepper with BER-like symptoms.
(Photo by Joshua Mayfield)
Figure 5. Pepper Anthracnose with BER-like symptoms.
(Photo by D. Langston, UGA)
Question 4. Is irrigation adequate?
Some people believe the relative humidity and transpirational rates of tomato and pepper during the spring season are the real keys to understanding what factors trigger BER in fruiting vegetables. Fluctuations of soil moisture, as happens during a week of off-and-on rain, may trigger BER due to irregular transpiration rates, affecting the quantities and timing of water and Ca moving up the xylem. Conversely, during hot, dry weather when transpiration is occurring at a much faster rate, developing vegetative parts such as growing leaves and stems become greater sinks for Ca than developing fruits. Lastly, as the waxy outer layer of a tomato or pepper fruit develops, the fruit’s transpiration rate decreases because water movement through the epidermal cells and evaporation into the outside air become difficult. The resulting decrease of Ca that flows into those young fruit tissues via xylem transport is believed to contribute to the onset of BER.
Recommendation: Some research findings have quantified a decrease of BER incidence with increased irrigation rates. However, no recommendations exist for determining the critical moisture levels required in soils to minimize this disorder, nor is information available regarding the severity of moisture deficits triggering BER.
Figure 6. Blossom-end rot of bell pepper.
(Photos by E. Maynard, Purdue University)
Figure 7. Blossom-end rot of jalapeno pepper.
For now, the “feel” method is still the most tried and true method of assessing soil moisture in the field. Along the row and out to the shoulders of the bed, the soil should be moist enough to form a ball in your hand and not break apart. The optimal time to increase irrigation and ensure that adequate moisture is being supplied is from first bloom set through fruit development. If BER initiates in fruit, it is believed to be during this early stage of development.
Certain occasions exist where farmers run irrigation pumps “round the clock” and soil still will not form and hold a good ball shape. This may indicate that irrigation demand during the fruiting period is greater than that for which the pumping system was designed.
Summary
It is believed that both nutritional and environmental factors need to be considered when diagnosing BER and recommending treatments. First, a correct diagnosis must be made to avoid recommending costly fungicide sprays when none are needed. Next, a careful examination of a grower’s soil test and leaf analysis records, in addition to their irrigation management practices, will help determine if additional Ca alone or in combination with increased irrigation scheduling will solve the problem. Equipped with a basic knowledge of plant growth, fruit development and Ca movement in soils and plant xylem tissue, growers will have the tools necessary for diagnosing and correcting the adverse effects of blossom-end rot.
Diagnosis Guide
Although no data exists to quantify how much annual economic impact blossom-end rot has on Georgia’s bell pepper and tomato industries, it is safe to say that significant loss of fruit occurs during the spring crop season, especially during hot, dry years. What is also unknown in the vegetable research realm is if a single cause leads to BER, or if (as past research indicates) multiple factors contribute to its occurrence. One fact that everyone can agree on is that when BER is first noticed in the field, prompt action is essential to halt further incidence. Four simple questions in the field will lead to a timely diagnosis and treatment of the problem:
Question 1. Is the problem disease- or nutrient-related?
There are only a few common fruit disorders resembling BER that can lead to an incorrect diagnosis of the problem. Fruit anthracnose may occur on pepper and tomato fruit, but only on the side walls. The same is true for sunscald, which appears on pepper fruit sidewalls and is pale in color. Buckeye rot, caused by Phytophthora, and cucumber mosaic virus (CMV) also resemble BER, but these disorders occur more infrequently than anthracnose. Blossom-end rot is uniformly dark brown and black in color, and appears ONLY on either the lower fruit sidewall or the blossom end of smaller and developing fruit. Often, symptoms will occur as far as 1/3 to halfway up the fruit, but will NEVER start at the stem (calyx) end. Also, BER symptoms will tend to appear during the first fruit set as, early on, growers are unaware of the problem until it’s too late. If these symptoms all correspond, the fruit has BER.
Recommendation: If these conditions all hold true, proceed to Question #2.
2. Is calcium fertilization adequate?
Examine liming and gypsum application records, along with the current season’s pre-plant soil test reports. If pre-plant soil test Ca levels are in the medium (801 to 1,200 lbs. Ca/acre) or high range (>1,200 lbs. Ca/acre), it is assumed that soil Ca levels are sufficient for crop growth. This is even more true for soil pH ≥ 6.0, with supplemental gypsum or lime being applied pre-plant at levels of 500 to 1,000 lbs./acre or higher.
Recommendation: If these conditions exist, proceed to Question #3.
Equally important to soil test results is plant tissue analysis. For bell pepper, sufficient leaf tissue percent Ca content just prior to (or at) early bloom stage should be within the range of 1.0 to 2.5 percent. For tomatoes, percent Ca content prior to (or at) early bloom should be within the range of 1.25 to 3.20 percent. Tissue levels below these would point to a possible emerging Ca deficiency.
Recommendation: No specific recommendations exist for alleviating a low soil Ca level after planting. However, calcium nitrate (CaNO3) is a water soluble source of Ca and nitrogen (N) and is routinely injected in drip irrigation systems. Some research has begun on a relatively new material, calcium thiosulfate (CaS2O3), which also is available for drip injection systems. Injections of soluble Ca sources should begin at bloom and proceed until fruit is approximately golf ball-sized. This is believed to be the critical time when calcium must move into developing fruit to avoid onset of BER.
(Photo by Joshua Mayfield)
Although some people believe foliar sprays can correct Ca deficiency in developing fruits, research is very inconclusive on this issue. What is well known is that Ca only moves in the plant via the xylem and moves with the transpirational water flow from the roots, up the plant and into developing leaves. Calcium has no ability to flow from the leaves via the phloem to the developing fruit. In addition, once fruit has grown to golf ball size, the waxy outer layer has developed and is believed to be quite impermeable to water. Therefore, it is recommended that all Ca supplied to fruiting vegetables be applied via the irrigation water so as to maximize uptake by roots.
Recommendation: If liquid fertilizers are already being used, proceed to Question #3.
Question 3. Is nitrogen and potassium fertilization excessive?
Research has shown that Ca in soil solution competes with potassium (K), magnesium (Mg) and ammonium-nitrogen (NH4-N) for uptake in the plant. Although no established guidelines exist to determine what proportions of these nutrients in soil or plant tissue are appropriate, it is known that excessive shoot growth resulting from overfertilization of N and K during early bloom and fruiting stages is a major contributor to BER in developing fruit. Since Ca moves with the transpirational water flow, water is going to go to areas of new shoot growth that have the greatest transpirational demand. Calcium will therefore be deposited in the new shoot and leaf tissues that result from excess fertilization, and little will end up in developing fruit where it is needed most. At early bloom stage for bell pepper and tomato, leaf N and K analysis should both be within 4.0 to 6.0 percent. Levels higher than these may indicate excess fertilizer.
Recommendation: Cut rates of N and K if excessive top growth is occurring. Switch N source to CaNO3 or begin injections of CaS2O3 at bloom stage. If these steps are already being implemented, proceed to Question #4.
(Photo by Joshua Mayfield)
(Photo by D. Langston, UGA)
Question 4. Is irrigation adequate?
Some people believe the relative humidity and transpirational rates of tomato and pepper during the spring season are the real keys to understanding what factors trigger BER in fruiting vegetables. Fluctuations of soil moisture, as happens during a week of off-and-on rain, may trigger BER due to irregular transpiration rates, affecting the quantities and timing of water and Ca moving up the xylem. Conversely, during hot, dry weather when transpiration is occurring at a much faster rate, developing vegetative parts such as growing leaves and stems become greater sinks for Ca than developing fruits. Lastly, as the waxy outer layer of a tomato or pepper fruit develops, the fruit’s transpiration rate decreases because water movement through the epidermal cells and evaporation into the outside air become difficult. The resulting decrease of Ca that flows into those young fruit tissues via xylem transport is believed to contribute to the onset of BER.
Recommendation: Some research findings have quantified a decrease of BER incidence with increased irrigation rates. However, no recommendations exist for determining the critical moisture levels required in soils to minimize this disorder, nor is information available regarding the severity of moisture deficits triggering BER.
(Photos by E. Maynard, Purdue University)
For now, the “feel” method is still the most tried and true method of assessing soil moisture in the field. Along the row and out to the shoulders of the bed, the soil should be moist enough to form a ball in your hand and not break apart. The optimal time to increase irrigation and ensure that adequate moisture is being supplied is from first bloom set through fruit development. If BER initiates in fruit, it is believed to be during this early stage of development.
Certain occasions exist where farmers run irrigation pumps “round the clock” and soil still will not form and hold a good ball shape. This may indicate that irrigation demand during the fruiting period is greater than that for which the pumping system was designed.
Summary
It is believed that both nutritional and environmental factors need to be considered when diagnosing BER and recommending treatments. First, a correct diagnosis must be made to avoid recommending costly fungicide sprays when none are needed. Next, a careful examination of a grower’s soil test and leaf analysis records, in addition to their irrigation management practices, will help determine if additional Ca alone or in combination with increased irrigation scheduling will solve the problem. Equipped with a basic knowledge of plant growth, fruit development and Ca movement in soils and plant xylem tissue, growers will have the tools necessary for diagnosing and correcting the adverse effects of blossom-end rot.
Were they big healthy plants otherwise?
It also sounds like you could have had high nitrogen ratios. Too much nitrogen will induce just what you described. If this is the case... then boosting your phosphorus and potasium levels will help... as well as adding in mulched leaves (to lock up the amonia) and mixing gypsum and epsom salts into the soil (for calcium, suphur and magnesium)
It also sounds like you could have had high nitrogen ratios. Too much nitrogen will induce just what you described. If this is the case... then boosting your phosphorus and potasium levels will help... as well as adding in mulched leaves (to lock up the amonia) and mixing gypsum and epsom salts into the soil (for calcium, suphur and magnesium)
The photos in the post above show pods that are well into BER symptoms. The earlier pod symptom is fruit wall softness - it may even look "watery". The plant itself may appear to be healthy otherwise. As noted above, calcium is most recommended to prevent BER. I start using CalMag by Botanicare as soon as the plants kick into production stage (though you can use another product if it's more readily available to you, just make sure it's formulated for tomatoes/peppers and has high calcium.)
Thanks for all the info. None of my pods looked anything like what is pictured above. It was a case of some plants flowering, but producing few, if any, pods. I'll need to read again everything that has been posted above. My Moruga, for example, was about 4' tall, and produced 1 ripe pod. What a killer that 1 pod was, though!
It doesn't sound like blossom end rot to me although there isn;t a lot to go on. Other than the fact your plants aren't setting pods how did the nursery diagnose the issue? I wonder if something nasty has happened to all your pollenating insects like bees? Assuming you are growing outside?
I still vote either bad genetics, too high of nitrogen ratios in the soil, or both. When the nitrogen ratios are too high (but not too too high)... the pepper plant will grow very well... and appear healthy, but it will produce few if any peppers. For example, last year I had a 7 foor tall black hab that looked great... except that i never got one ripe pod off of it before the frost. The spot in which it was planted was previously a pile of manure (which is nitrogen rich). If i had fed it some extra phosphorous and potassium it would have done better.
Noah, I agree high nitrogen does also sound likely as a candidate too. I am always worried about soil salinity, would flushing the soil/nitrogen just have worked as well for your black hab as adding phosphorous and potassium do you imagine?
Yes... flushing the soil helps as well...
The season before last... i actually had an entire section of my garden produce next to nothing, because I had another heap of manure resting just up hill from that section waiting to be tilled in next season. Well, every time it rained, the water would run through the manure and onto that portion of the garden causing all of the plants to be luscious sprawling plants (tomatos, peppers, melons)... but i never got one tomato and only picked a few peppers from the affected area.
Also... high nitrogen ratios in fetilizer during fruit production can cause cracks in the fruits... which almost resmbles BER. (I think in part because it affects the calcium ion exchange channels... creating an imbalance that mimics calcium defficiency which is the cause of BER... so that your soil could have planty of calcium already but its being locked out (jammed) by the nitrogen uptake as referenced in BSPH's post)
Were your plants potted, in raised beds, or in the ground and did you amend the soil?
Also... BER spray is a rip off... calcium is absorbed through the roots.
The season before last... i actually had an entire section of my garden produce next to nothing, because I had another heap of manure resting just up hill from that section waiting to be tilled in next season. Well, every time it rained, the water would run through the manure and onto that portion of the garden causing all of the plants to be luscious sprawling plants (tomatos, peppers, melons)... but i never got one tomato and only picked a few peppers from the affected area.
Also... high nitrogen ratios in fetilizer during fruit production can cause cracks in the fruits... which almost resmbles BER. (I think in part because it affects the calcium ion exchange channels... creating an imbalance that mimics calcium defficiency which is the cause of BER... so that your soil could have planty of calcium already but its being locked out (jammed) by the nitrogen uptake as referenced in BSPH's post)
Were your plants potted, in raised beds, or in the ground and did you amend the soil?
Also... BER spray is a rip off... calcium is absorbed through the roots.
I think this is pinned around here somewhere but just in case.
Reasons for flower drop.
1. Day temp too high >95F
2. Night temp too low <65F or too high >85F
3. Too much nitrogen fertilizer
4. Too much water
5. Low light levels (reduces fertility).
6. Very low humidity (reduces fertility)
7. Poor air circulation (air circulation contributes to pollination).
8. Lack of pollinating insects.
9. Size of pot
10. Too much mineral in feedwater.
11. Too much grower attention/anxiety.
Reasons for flower drop.
1. Day temp too high >95F
2. Night temp too low <65F or too high >85F
3. Too much nitrogen fertilizer
4. Too much water
5. Low light levels (reduces fertility).
6. Very low humidity (reduces fertility)
7. Poor air circulation (air circulation contributes to pollination).
8. Lack of pollinating insects.
9. Size of pot
10. Too much mineral in feedwater.
11. Too much grower attention/anxiety.