Vegetative and Reproductive Nutrients with John Kempf

published in peer-reviewed publications, but there are many incredible stories and a lot of knowledge that has not been published and that hasn't been shared with many people. I started advancing eco agriculture in two thousand six. to bring this knowledge together in a more coherent fashion and incorporate it into products and growing systems that growers can easily put into practice.

It's my personal mission to have these regenerative agricultural systems become adopted globally and become the mainstream, the status quo, against which all other growing systems are compared. To help achieve this goal, I want to share the knowledge. that we have learned in the last decade and make it available to everyone. While we have developed products at AEA that embody the principles of regenerative agriculture systems and make them easier for growers to apply,

This knowledge and these principles can be applied anywhere, and when they are applied properly, they will always increase farm profitability and resilience to climate stress. If you have any questions, suggestions, comments,

And so I wanted to share with some thoughts with you about some of the things that we've observed and that we have learned over the years. There are some nutrients which drive strong vegetative growth, and there are some nutrients which drive strong reproductive growth and reproductive development. And And then for some of these nutrients in both categories, they interact with and synergize with different groups of plant hormones.

So you can have this synergistic effect where you have certain nutrients synergizing with certain hormones and then others antagonizing other hormones. You have this kind of two tier effect where you can really shape how Plants trigger reproductive buds, reproductive bud development. and fruit wood development. So I wanted to talk about some of those pieces. So perhaps to begin from a nutrient management perspective, there are four nutrients which drive strong

vegetative growth or a different terminology, different way of thinking about it might be to say that they have a strong male energy and male energy development. So that that is strong vegetative growth. So those four nutrients which drive vegetative growth are nitrate nitrogen, specifically nitrate, not ammonium or urea or other forms, and potassium and chloride and calcium. So

Those four, nitrate, potassium, chloride, calcium, will drive very strong vegetative growth. And we can see this being expressed in how we manage agronomy and plant nutrition on a number of different crops. For many grassy plants, such as corn and sorghum, et cetera, we use nitrate to get our strong vegetative growth.

shot uh with with very strong nitrogen applications. And this is true of many tree fruit production as well, uh almonds, etc. And then there are other crops where we use potassium to get a very strong vegetative growth response, such as alfalfa. Chloride also contributes a very strong growth response because of the energy similarities that it carries to potassium and some of the ways that it functions in cells and in cell membranes. So when you have these four nutrients.

giving us strong vegetative growth. On the reproductive side, essentially everything else, all the other nutrients, excluding these four, will trigger a slight reproductive response in plants. But there are three in particular which are the heavyweights of the reproductive category. The three nutrients which drive strong reproductive development or bud initiation would be manganese.

The the way to think about this as as this relates to plant management and crop management is that there is both vegetative growth and reproductive growth. happening all the time in every single organelle and every cell within the plant. There is never a complete dominance where you have one hundred zero or even ninety ten. ratio between these two. Instead, this is a a relatively sensitive fulcrum balance beam where the ratio might be fifty-five, forty five.

where you have fifty-five percent vegetative energy, forty-five percent reproductive energy, or vice versa. So what this means, because there is both vegetative and reproductive growth happening all the time, it means that Very small amount of nutrient applications can actually trigger and switch from one side to the other. And for example, one of the common challenges that we see sometimes with tomato production, some varieties of tomatoes under some management systems.

When we have an overapplication of nitrogen, which converts in the soil to the nitrate form, we end up with a tomato plant that is lush and green, has a lot of vegetative energy, but has no fruit. You have this beautiful green plant, but it doesn't have a single blossom on it. Doesn't have a single bud. That's a plant that is completely vegetatively dominant. You can switch a plant like that from being vegetative dominant to reproductive dominant with a single foliar application.

of manganese and phosphorus, for example, the the nutrients which have a very strong reproductive trigger. You can you can literally Paint a tomato field from green to yellow in a matter of about seven to ten days. with the right foliar application. So it's possible by managing nutrients to produce a very rapid switch from vegetative growth.

to reproductive growth or vice versa. But there's another layer here, which is where it starts getting to be really fascinating. And when we understand how these two layers interact, we can begin producing very reproductive dominant plants that also have very strong vegetative growth, but it's very high quality vegetative growth. And I want to describe this because it's very important. So The second layer is understanding how plant hormones interact with these base nutrients. So there are

five major groups of plant hormones. You have oxens, your cytokinons, your gibberellins, ethylene, cystic acid, etcetera, acetic acid. But the two that I want to focus on are kind of the two foundational groups for plant development, which would be auxens and cytokinines. So auxins are, for those of you not familiar with this terminology, auxins is spelled A-U-X-I-N-S. And you can do more research and looking at some of these various plant hormones.

The the very simplistic explanation is that uh oxens are produced in two parts or two locations inside the plant. One is they're produced in growing shoot tips. So The shoot tip at the top of the plant, the apicle meristem, has to be growing every day, every twenty four hours.

And as that growing shoot tip is growing, it is producing oxen. The second place that auxin is being produced is in the developing seed. So once you have blossoming and pollination and the seed begins forming, the seed begins developing. Now you have oxen production in the seed. Now the interesting part about auxin is that uh you you can think of oxen to some degree as being the sugar magnet. Wherever auxin is.

in the highest concentrations, that is where the sugar goes from the photosynthesis factory called the leaves. So every 24 hour photo period, as we have photosynthesis and sugar production in the leaves, That sugar moves out of the leaves in the afternoon and evening, moving to the sugar sinks.

And those sugar sinks are determined by the oxen concentrations. So when we have high oxen concentrations in developing seed or in the new shoots, that's where most of the sugar is going to go. Now the interesting part is that oxen, when it's produced in the shoots or in the seeds, it but particularly in the shoots, it will move out of the shoot, move down through the plant, out through the root system to the growing root tips. And when it gets to the growing root tips,

it shuts down cytokinin production. So let's switch gears from auxin to cytokinin for just a moment. Cytokinons, unlike auxins, auxins are produced in growing shoot tips and seeds. Cytokinins are produced in growing root tips. So again, this means that we need to have the root tips growing every single day for new cytokinin production if we want to maintain a balance between cytokinines and oxen.

Oxons are trying to be dominant and suppress cytokinin formation. Cytokinens are trying to be dominant and slow down shoot growth and oxen formation. So these two

are constantly butting heads. This becomes very important because the when we think about vegetative growth, vegetative growth is not all equal. We know that we can have vegetative new shoot growth on let's say a cherry or an apple tree or a peach or any any tree fruit or berry plant or any annual vegetable crop, we can have poor quality shoot growth and high quality shoot growth. And the way that that's commonly defined and looked at is

on annual crops and also to some degree on perennial crops, we look at internode spacing. We want to have internodes spaced as tightly together as possible. So if we have internodes that are two inches apart instead of being six inches apart, we know that we have that much more opportunity for reproductive buds in the future and that is much higher quality fruit wood. At the same time, wood that has more closely spaced internodes

also is going to have a higher carbon content and higher carbohydrate concentrations. So again, you have the potential to have much more reproductive fruit wood. So when we look at quality of shoot growth, we're looking at inner node spacing for all crops and on tree fruit, We're also looking at

carbon content and what really defines high quality shoot growth. The interesting part is that you can have equally rapid growth. You can have a shoot that extends eighteen inches in three weeks. I'm just making up a hypothetical example. A chute that extends eighteen inches in three weeks with internodes that are spaced at two inches or inner nodes that are spaced at six inches.

The same amount of lateral growth can happen in the same amount of time, but the number of internodes that are spaced along that chute are determined by the nutrient ratios and by the hormone ratios that are present inside the plant.

So this brings us back to our discussion of these four nutrients which drive vegetative growth and how they combine with these two hormones.

Actually, before I go there, let's back up on just one piece. I mentioned that oxens are produced in two locations. One is in the shoots and the second is in the seed as the seed is developing. What often happens for many crops is as the seed begins developing, as the fruit begins developing, it becomes the dominant oxen source and it becomes the dominant sugar sink.

So most of the sugars that are being produced are moving into the fruit, which is appropriate as long as not so many sugars are moving into the fruit that they are sabotaging root growth and sabotaging shoot growth. So The the root growth and the shoot growth will be the first to get less sugar. The sugar is always going to move into the fruit because the plant has a desire to reproduce. We can monitor sugar.

production, photosynthesis, and the overall energy of a plant or a tree by monitoring the shoot growth while we have fruit on the plant or on the tree. So we do if we're growing blueberries or cherries or stone fruit or apples, it doesn't really matter. They're the same principle holds true. We want to have the new Shoot tips constantly growing as long as there is fruit on the tree. It doesn't need to be growing rapidly.

but we never wanted to set the terminal bud. The moment the growing shoots set their terminal bud, we know that has happened because the plant did not have enough energy to both fill the fruit and maintain shoot growth. So we can actually look at shoot growth and shoot extension as an indicator for whether a plant had enough energy. But there's another

aspect to this as well, which is the shoot growth is actually not the first to drop off and to decline. It's actually the root growth which is the first to be sacrificed. So because shoots are producing oxen, And seeds are producing oxens, but the roots are not producing oxens. So the oxen concentration in the root system is the first to decline, which means that it is the sugar sink which will get the least amount of sugar and will no longer be supplied sugar first.

when the plant cannot produce enough to fully fill the fruit load that it has on the tree. What this means for annual plants in particular, and to some degree perennials as well, is when the Root system no longer gets enough sugars in every 24-hour photo period. It no longer has the energy to keep growing. So root growth. declines, or in many cases, stops entirely. Now, when the root growth stops, remember you need cytokine production in growing root tips.

So when the growing root tips stop, you no longer have any new root tip extension, that means you also halt the production of cytokinons. Now there is no cytokinines, there are no cytokinons moving up to the upper parts of the plant to trigger. the initiation of reproductive buds. So on on some crops, take tomatoes for example, it's very common to see some or indeterminate tomato varieties

that are staked and tied, fresh market tomatoes. The field looks like an absolute picture. Every row looks like a hedge. They're 40 to 42 inches tall. The crop that the top is very dense. And it looks like a clipped hedge. You have very tight inner node spacing, three to four inches apart. And as the fruit begins sizing and the seed begins producing a lot of oxen, the root system is

No longer getting enough sugar because now the sugar is moving into the fruit. And all of a sudden you see this rapid shoot extension happening out of the top of the plant, where you get now get internodes where for the first time 10 weeks of this plant's life, 10, 12 weeks of this plant's life, you have all these tight inner nodes that are three to four inches long. And now you get this rapid shoot extension where the shoots

are six to eight inches long or ten to twelve inches long. And all of a sudden this tight clipped hedge appearance becomes very ragged. You have all this shoot extension happening out of the top of the plant. That is your first indication your first signal that the root system has gone into decline. There is no longer any active root growth because sugars are all moving into the fruit and no longer moving down to the root system. When that happens you see that is that is the trigger

that triggers a lot of root disease susceptibility. So when you first begin seeing challenges with Phytophthora or Rhizoctonia or anthracnose or any any number of these various soil borne diseases. it often becomes exacerbated and begins developing quickly when you reach this stage of fruit development. Because

The plant is not producing enough sugars to sustain both the fruit and the root system. And I should just clarify that plants, this this doesn't need to be the case. This is what is common. This is what is normal, but it's not what needs to be the case. It is possible plants have the genetic capacity to photosynthesize to much higher levels and be able to fill.

a fruit load and be able to sustain constant root growth and root development throughout the entire fruit fill period. So circling all the way back

To understand the synergies between nutrients and hormones. There are of the four vegetative nutrients. Three of them have a synergistic relationship with oxen. They drive rapid vegetative development and they drive oxen formation. Those three nutrients are Nitrate, potassium, and chloride. So when a plant has a generous supply of nitrate, potassium, and or chloride, either of those three can trigger this response.

This is when you get very rapid growth, but you have auxin dominance. And because you have auxin dominance, you have very wide internode spacing, where you'll have internodes that are six to eight inches apart or longer, depending on what plant and crop we're talking about. But the fourth Vegetative nutrient drivers, calcium, does not have a synergistic relationship with oxen.

Instead, it has a synergistic relationship with cytokinin. So this is this is kind of the secret. You can achieve the same amount of shoot extension when you use calcium to drive your vegetative growth. as you can when you use nitrate or potassium or chloride. But instead of having internodes that are spaced, that are widely spaced, you now have internodes spaced because you have cytokinin dominance instead of oxen dominance.

And this is also how you produce high carbon wood on perennial tree crops and berries, etcetera. So the key, kind of the the bottom line, uh if I were to summarize it all uh and and wrap it all up very neatly, if you want to produce Plants that tree structure and plant structure that can support and sustain a heavy fruit load. And

be extremely reproductive and extremely healthy while also getting strong vegetative growth, high quality vegetative growth at the same time. You want to balance plant nutrition in such a fashion so that you have Cytokinin dominance and calcium dominance at the same time. In other words, You want to get your vegetative growth energy from calcium instead of from nitrate and potassium and chloride. You still need those nutrients, nitrate and potassium in particular on some crops.

So I'm not suggesting you discontinue the use of those, but instead of using those nutrients to get your vegetative growth response, when you use calcium to get your vegetative growth response, you can achieve the same quantity of growth. but a much higher quality growth. And that is the bottom line

for producing exceptional yields and quality at the same time. Thanks for listening. I appreciate all the work that you guys do in the field and please give me any feedback and uh let me know if there's any questions that you have on this topic and I will follow up. Thanks guys.

And that to grow healthy plants, we must first think differently about agriculture, about empowering life instead of suppressing life, about regeneration instead of degeneration. To achieve this, We formulate and sell products that help growers produce higher quality yield with less risk of crop failure. In short, we help growers make more money with less risk. Thank you for listening.