Tomato Plants and Sulfur

[Hudson_WY]

I ran across this article about supplementing Tomato plants with Sulfur. We have been supplementing our tomato plants with sulfur for several years and have found the information in this article to be true. Maybe sulfur is why our tomatoes have such great taste!!? What are your thoughts - experiences?

http://homeguides.sfgate.com/informa...nts-29024.html

Growing your own juicy, red tomatoes is relatively easy. But when leaves yellow or the fruit fails to mature, sulfur can help, both in the soil and dusted on leaves as a fungicide and insecticide. Sulfur and copper are the only fungicides allowed for use on certified organic produce.

Sulfur can be used in the soil or on the tomato plant to help develop tasty tomatoes.

Soil Nutrient

While sulfur is only needed in small amounts as a micronutrient to grow tomatoes, sandy soils can be deficient in sulfur. Sulfur helps form organic compounds that help impart flavor to tomatoes. Tomato plants with yellow-green lower leaves and elongated, woody stems may need more sulfur in the soil. The amount of additional sulfur needed is often fairly low, so a thin layer of compost of about one to two inches added to the soil may provide enough sulfur. Sulfur can also be found in many fertilizer mixes. Use about 1/2 cup per tomato plant. Work it into the soil when the tomatoes are small.

Fungicide and Insecticide

Powdery mildew spores can be carried on the wind to tomato plants late in the season. This fungus causes tomato plant leaves to develop yellow spots, and can eventually kill the leaves. Sulfur can be sprayed on the plants to reduce infestation. Another tomato pest, russet mites, can be controlled with sulfur, but it may take several applications. Sulfur can also be used to prevent an infestation.

Applying Sulfur

Sulfur can be applied as a dust or as a wettable powder. When applying as a dust, use a hand-cranked dust applicator in dry, windless weather. Coat the leaves and stems of the tomato plant lightly. The wettable powder form of sulfur is stirred into water. However, it doesn't dissolve. It is applied with a specially designed sprayer.

Cautions

Sulfur can damage tomato plants when the weather is hot, and should not be used if temperatures climb above 90 degrees Fahrenheit. If squash and melons are planted near tomatoes, do not use sulfur, as it can injure these plants. While sulfur is less toxic than many chemical pesticides, it is best not to get it on your skin or in your eyes as it can irritate them. Avoid use on a windy day to keep from inhaling the sulfur or it spreading to other areas. Wear a long-sleeved shirt, long pants, eye protection and plastic gloves when applying sulfur. Wash tomatoes thoroughly before eating them to remove any sulfur residue.

[AKmark]

MgSO4/ Epsom Salts, is how we apply it. I buy it by the 55lb bags, it is critical for container growing. Our flower formula Technigro has S added, I have not seen much difference between it and Jack's Peat Lite that I also use which does not have it, but I do supplement MgSO4, so maybe it's a wash.

I was on the run when I posted the first part of my thoughts, so edit. I don't think S affects flavor like K does, or maybe even Mg. Mg is central to the chlorophyll molecule which through photo synthesis makes nice big green leaves possible, and those directly add sugar to the plants fruits. I never have added it separately from Mg, it is a common practice just to add Epsom Salts. Lack of K results in grey wall, blotch ripening, yellow shoulder, and the fruits are horrible compared to well grown tomatoes.

[PaulF]

Every year or two sulphur get applied to my garden. Not so much for flavor addition but to amend the soil pH from normal 8.4 to 8.6 down into the 7.5 to 7.8 range. Whether my tomatoes taste better at a lower pH is questionable. That depends more on variety and weather than sulphur content in my opinion. Hard to tell since the difference has not been thought about before.

[Gardeneer]

Interesting discussion.
Seems that I am in good hands. My soil test result show good Sulfur index.
I also use MgSO4 regularly. PLUS my soils is very rich in K. Thanks in part to the wood ash that I added/amended with. Am I going to get tasty tomatoes or what ?

[Gardeneer]

Just a side note :
I have heard this few years ago that pepper plants can benefit from some sulfur supplement.
Somebody said bury some matched in the soil.
I have also heard about benefit of some iron and table salt ( Na ) to improve the taste.
Anybody know about those ?

[AKmark]

Originally Posted by Gardeneer

Just a side note :
I have heard this few years ago that pepper plants can benefit from some sulfur supplement.
Somebody said bury some matched in the soil.
I have also heard about benefit of some iron and table salt ( Na ) to improve the taste.
Anybody know about those ?

Epsom Salts...
https://hydro-gardens.com/product/pe...-bag-11-11-40/

[Gardeneer]

Originally Posted by AKmark

Epsom Salts...
https://hydro-gardens.com/product/pe...-bag-11-11-40/

Right , Mark.
Most people think of Epsom salt as Mg source. But it is also a sulfur source ( MgSO4).
Ammonium Sulfate is another one ( Lilly Miller 21-0-0 ).

[AKmark]

Originally Posted by Gardeneer

Right , Mark.
Most people think of Epsom salt as Mg source. But it is also a sulfur source ( MgSO4).
Ammonium Sulfate is another one ( Lilly Miller 21-0-0 ).

Yep, more S than Mg in those bags.

[Worth1]

I'm going to use Epsom salts this year in two of my raised beds because all they are is big containers.

[Lindalana]

I am wary about using elements. Elements have places, proportions and different formulas and more is not better.
For example sulfur can potentially harm whole lots of living things in the soil as sulfuric acid ph is 1. Slow release fert is " slow" because it is covered in chemical sulfur. Potassium often comes as potassium chloride and 2ppm is enough to chlorinate water and potassium chloride will give you 50-200 ppm of chloride.Too much potassium disintergrates clay and compacts soil.

Garden Gypsum is 22% Calcium and 17% of Sulfur.
From my favorite source - smilinggardener
"Sulfate can enhance calcium availability and is used by plants in several ways.

It’s used in chlorophyll formation, and helps promote the formation of nitrogen-fixing root nodules in legumes.

Most of soil’s sulfur content is tied up in its organic matter. Because it’s an anion rather than a cation, it can’t bond to the cation exchange sites in clay, so having lots of organic matter is really important for providing and keeping sulfur in the soil.

Gypsum, discussed in the calcium section of the last lesson, is the way to go for organics."
I do use gypsum as source of Ca and Sulfur, especially good if applied in the fall to give it time to work.
Would certainly prefer molasses, compost, humic acids or seaweed to provide my micro or macro nutrients.
As for table salt- again is is sodium chloride. I have applied it to my garden because my soil is deficient in both of those elements but would be wary of no soil test done.
Additionally it is important to remember that it is not only single element application but proportions of each element. For example magnesium has 1.7 times more exchange capacity than an equal amount of calcium, so we use correspondingly less magnesium when we’re trying to raise magnesium levels.

[b54red]

I believe the biggest flavor enhancement derived from adding sulfur is because it allows the soil ph to be lower and thus more elements and minerals can be taken in from the resulting soil. A few years ago my soil ph got very high from using massive amounts of fresh mushroom compost which turned out to have a very high ph. During that time I noticed most of my tomatoes were milder in flavor and had a lot of trouble taking up needed iron which was plentiful according to the soil samples. It also restricted uptake of phosphorous and for some reason my potasium also got very low. I started a regimen to lower my ph and added a lot of greensand to my beds as well as supplemental potassium. I have been adding pine bark fines which are acidic as well as heavy doses of cottonseed meal which is also very acidic and slowly but surely my ph has come down to a great level from the previous highs of up to 8.5. My tomatoes have been much healthier and so much tastier the past few years. I also think the additional potassium results in far tastier tomatoes because the most immediate result from the addition of the extra potassium was much more flavorful tomatoes even before the ph got down low enough. This is all just my observation with no scientific explanation but I just have to believe my eyes and taste buds.

Bill

[AKmark]

Originally Posted by Lindalana

I am wary about using elements. Elements have places, proportions and different formulas and more is not better.
For example sulfur can potentially harm whole lots of living things in the soil as sulfuric acid ph is 1. Slow release fert is " slow" because it is covered in chemical sulfur. Potassium often comes as potassium chloride and 2ppm is enough to chlorinate water and potassium chloride will give you 50-200 ppm of chloride.Too much potassium disintergrates clay and compacts soil.

Garden Gypsum is 22% Calcium and 17% of Sulfur.
From my favorite source - smilinggardener
"Sulfate can enhance calcium availability and is used by plants in several ways.

It’s used in chlorophyll formation, and helps promote the formation of nitrogen-fixing root nodules in legumes.

Most of soil’s sulfur content is tied up in its organic matter. Because it’s an anion rather than a cation, it can’t bond to the cation exchange sites in clay, so having lots of organic matter is really important for providing and keeping sulfur in the soil.

Gypsum, discussed in the calcium section of the last lesson, is the way to go for organics."
I do use gypsum as source of Ca and Sulfur, especially good if applied in the fall to give it time to work.
Would certainly prefer molasses, compost, humic acids or seaweed to provide my micro or macro nutrients.
As for table salt- again is is sodium chloride. I have applied it to my garden because my soil is deficient in both of those elements but would be wary of no soil test done.
Additionally it is important to remember that it is not only single element application but proportions of each element. For example magnesium has 1.7 times more exchange capacity than an equal amount of calcium, so we use correspondingly less magnesium when we’re trying to raise magnesium levels.

This is a good post in regards to soil gardening, and this link will help explain the relationship of Cations/ micro elements, and anion root zones. Those who like organic, take note of the paragraph that explain Humic and Fulvic acids role with chelation.
https://www.linkedin.com/pulse/humic...ed-arif-sultan

[brownrexx]

You really do not know if your plants need sulfur or any other nutrient without doing a soil test. It is like deciding that your food needs salt without tasting it first.

I never add fertilizers, only compost and organic mulches and my soil test this year showed that phosphorus and magnesium were off of the scale high so adding more would be detrimental to my garden and adding sodium is rarely a good idea.

Many people want to add fertilizer every year and think that they are benefiting their plants but unless you are growing in containers and flushing out the nutrients, you probably don't need all of the nutrients that you are adding and they can build up to toxic levels.

[Worth1]

Originally Posted by brownrexx

You really do not know if your plants need sulfur or any other nutrient without doing a soil test. It is like deciding that your food needs salt without tasting it first.

I never add fertilizers, only compost and organic mulches and my soil test this year showed that phosphorus and magnesium were off of the scale high so adding more would be detrimental to my garden and adding sodium is rarely a good idea.

Many people want to add fertilizer every year and think that they are benefiting their plants but unless you are growing in containers and flushing out the nutrients, you probably don't need all of the nutrients that you are adding and they can build up to toxic levels.

I agree and I know I need fertilizer and sulfur or vinegar.
I fertilize heavy in the spring and dont mess with it much for the rest of the summer.
I also know my raised beds continuously go back to a strong alkali.
If I dont put vinegar in the water when I can the jars come out coated with calcium big time.
I did an elemental flame test on this stuff it is calcium.

[b54red]

Originally Posted by brownrexx

You really do not know if your plants need sulfur or any other nutrient without doing a soil test. It is like deciding that your food needs salt without tasting it first.

I never add fertilizers, only compost and organic mulches and my soil test this year showed that phosphorus and magnesium were off of the scale high so adding more would be detrimental to my garden and adding sodium is rarely a good idea.

Many people want to add fertilizer every year and think that they are benefiting their plants but unless you are growing in containers and flushing out the nutrients, you probably don't need all of the nutrients that you are adding and they can build up to toxic levels.

My soil test also showed high in both of those and it was explained to me by the specialist at the state agricultural school that adding compost and certain manures will raise your Phosphorus levels dramatically over time and if your soil is too alkaline the levels will keep rising. The problem is with soil too alkaline most of that phosphorus is not able to be taken up by the plants.

Worth is right about the vinegar treatment. It will release a lot of iron and phosphorus unless a solution too strong is used then it can be deadly because too much phosphorus is taken up by the plants. I actually had some tomatoes one year die from phosphorus poisoning when I was experimenting with using the vinegar soak to help when my soil was so alkaline. I started out with one ounce to the gallon and kept increasing it. I would do this to two or three plants and then go to the next two or three and increase the dose just to see what would happen. I can't remember how strong the solution was that caused the super intake of phosphorus but it was pretty high probably between 4 and 6 ounces of vinegar to the gallon. After a week almost all the plants looked much better except the ones receiving the lowest and highest concentrations of vinegar. I went online and looked up the symptoms the plants that received the highest doses of vinegar were showing and it was phosphorus poisoning. It only happened to the younger plants but it was a good caution to go slow. I still use the vinegar soak if any plants start showing iron deficiency and for my bell peppers which need a heavier dose of phosphorus than tomatoes so I do this for my bells every year at least once.

Adding cow or horse manure increases the amount of phosphorus and repeated adding will result in very high levels. The vinegar treatment is a good way to release some of the phosphorus in highly alkaline soils but it is a temporary thing as the ph will quickly return to its normal level a week or so later, maybe even sooner. I no longer use any cow or horse manure and only use chicken manure as they are not fed green plant matter. The specialist explained to reduce the phosphorus levels significantly would require growing a cover crop and removing it and not putting it back into the soil by tilling it in or composting it and returning it to the garden. He said it would take years of doing this to really take the levels I had down to normal but he did advise me not to rely too heavily on compost made from the green stuff from my garden. I started relying on cottonseed meal much more because it is relatively low in phosphorus and is very acidic. I still use some compost but much more sparingly and mostly for where my tomatoes and peppers and squash will be planted. I never compost those plants and always let them go out with the trash at the end of each season or whenever they are finished. Doing this has reduced the phosphorus and magnesium levels even though I use Texas Tomato Food regularly. This has also resulted in a much lower ph though still a bit too high. Everything in the garden is doing much better and I will continue this regimen as long as it continues to improve my garden.

The only drawback to not adding the large amounts of manure and compost has been a reduction in organic matter in my soil and thus a more sandy soil. I am going to try pine bark fines and peat to see if I can improve the soil structure without my old standbys.

Bill