Managing Nutrition at Critical Points of Influence

Hi friends, this is John. Welcome to our webinar about how to.

Manage nutrition at critical points of influence.

This webinar will be about the five biggest critical points of influence that determine yield and quality, and which nutrients need to be managed at these critical points.

Of influence and the different types of impacts that they can have on crop expression. When we think about critical points of influence, I first coined this term and started speaking about these critical points probably a decade ago. And the idea of a critical point of influence is that there is a narrow window of time when the plant.

Is undergoing a significant hormonal shift at different locations, specific locations on the plant.

Or there is something going on from a reproductive or growth perspective that has.

A significant influence on future yield and quality.

So there are a number of different critical points of influence for different varieties of crops.

We obviously have perennials and annuals.

We have what we think of as multi fruiting crops, crops which blossom and.

Pollinate over an extended period of time, such as tomatoes or cucumbers or soybeans.

And then we have what we think of as single fruiting crops, where all the blossoming and pollination happens in a.

Very condensed time window, such as tree fruit.

And so you have these different points.

That occur in different ways on different plants. But in general, these points are universal across all plants, at least across all reproductive plants.

So if you have blossoming and pollination.

That'S a critical point of influence that happens. And the same physiological processes or similar.

Physiological processes, similar hormonal processes happen in a tomato plant as occur in an apple tree.

So the profile and the interactions are.

Similar, but obviously they occur in a different sequence. So with apples, blossoming and pollination is.

The first thing that happens after dormancy break in the spring.

With tomatoes, it doesn't happen until after 10 weeks of vegetative growth. So these critical points of influence occur in a different sequence for different crops.

But the same foundational processes and principles apply regardless of which sequence they occur in.

So the idea is that as the.

Plant grows and develops, there's this constant expansion, contraction, energy going on.

There's this constant shift between vegetative dominance and reproductive dominance. We could have a conversation about what this means from a hormonal profile perspective.

Cytokinins versus auxins.

Generally when you have a reproductive dominant.

Plant, you have a cytokinin dominant plant.

Which means you have a dominant root system and more growing root tips then you have growing shoot tips.

I've discussed this in the past in the webinars. The short version is simply to Say.

That the healthiest plants that produce the highest yields and are the most pest resistant are plants which have a larger.

Root biomass than above ground biomass. And in the case of perennial trees and so forth, specifically, what we're speaking about is leaves.

So we need more growing shoot tips and this, excuse me, more growing root tips and more roots that were produced.

This year from a root flush than.

Leaves coming from the vegetative flush.

So there's this constant balancing action and interaction occurring between cytokinins and auxins, reproduction.

And vegetation, and reproductive nutrients and vegetative nutrients. So what we want to get into in this webinar is specifically, what are.

The five major critical points of influence that have the biggest impact on yield.

And quality for most crops, and what.

Are the specific nutrients that we need.

To manage at each of those stages, and what are the benefits that we can expect from managing them well at each of those stages? So I wanted to share an example.

Of a corn crop, what a corn plant looks like. So these are the various critical points.

Of influence when a corn plant switches from vegetative to reproductive and then back to vegetative again and then back to reproductive.

I wanted to share this just as.

An example of the many different switches that occur as the plant shifts from vegetative to reproductive back and forth throughout the growing season. The corn plant actually has 13 of these different critical points of influence. And as I described a moment ago.

Of course, these shifts occur in a.

Different sequence in a different series for different crops and different plants. Some plants might only have one or.

Two shifts, and some might have as.

Many as 15 or 16.

It really depends on each individual plant's growth factor and the way that it.

Was developed and what is natively adapted for. So during this webinar, I'll be focusing.

On these five major critical points. Bud initiation, bloom or blossoming, and pollination, cell division, fruit fill and ripening.

So we're going to be focusing on these five pieces, these five sections.

First, we start off with bud initiation. So in bud initiation, the pieces that.

We can influence, what are the changes and the differences that we can make on a crop when we manage this particular critical point of influence? Well, the first is that we can influence the number of buds. So you can, when the plant has.

Proper nutrition, well balanced nutrition, you can significantly increase the number of buds that are initiated. Or in the case of some plants.

That are converted from vegetative to reproductive buds, you can increase the number of reproductive buds that you're looking that you have on a crop for some Crops.

This may not be desirable.

Other crops, it's very important.

The second factor that we can influence at this stage is bud uniformity. If we hope to have a condensed.

Harvest window in the future, if we're machine harvesting a crop or we want to have a high degree of fruit uniformity, then that needs to begin with.

A high degree of bud uniformity. The healthier a plant becomes, the more.

Robust and vigorous it becomes, the more uniform the buds become, to the point.

Where there is almost no difference between.

The primary blossom and the secondary blossoms. So if you're speaking about tree fruit, this might be the king or the.

Crown blossom, and then the secondary and sometimes tertiary blossoms around it. With blueberries, we have this distribution of.

Buds all the way along a stem.

The ultimate goal is to have all.

Of, from a health and performance, overall yield and performance perspective is to have.

All of those buds be the same size, have a high degree of uniformity, and open and blossom and pollinate at the same time. And that means fruit will all ripen.

And mature at almost exactly the same.

Time in a very condensed harvest window. The third factor that we can influence is overall bud size and energy.

And of course, it almost goes without saying that bud size and energy translates.

To future fruit size and in the.

Case of some crops, also the number of fruit per bud, in the case of cherries, for example.

And the next factor that we can.

Influence at this stage is blossom size, which also translates to ultimate fruit size. We can also influence the bloom timing.

On some crops, it's desirable to delay.

Timing and, or delay bloom and have bloom occur a little bit later to avoid any possible frost damage, freeze damage.

And for other crops, it's desirable to.

Move it forward and have it occur earlier. Moving it in either direction can be.

Influenced by the quantity and quality and.

Integrity, the balance of nutrition that is available in those buds.

I'll be describing exactly how to produce those.

So when you look at the overview, the summary of what we just spoke about, reproductive bud initiation at this critical.

Point of influence, we can impact the.

Number of buds, the uniformity of those.

Buds, the energy and the size of each of those individual buds, and the size of the blossom and the timing.

And the uniformity of the bloom. So what nutrients need to be managed.

At reproductive bud initiation to produce those effects? And I should mention that this reproductive.

Bud initiation, you need to know when this happens for your crop.

It obviously occurs at a different stage.

In the development cycle for different crops.

For blueberries, it occurs as they're going into dormancy.

For strawberries it occurs as they're going into dormancy. For corn, it occurs at four to six weeks after germination.

There's significant variation on when it occurs for different plants.

You simply need to know and understand when this point is for your crop.

And then manage nutrition very carefully in.

The two to three to four weeks that lead up to that point. Set the stage for really successful reproductive bud initiation.

When we look at which nutrients need to be managed, number one on top.

Of the list is calcium.

Because of course, we know and understand.

That we need to have an abundant supply of calcium to have strong cell division and produce as many buds and as many embryos per bud as possible.

Calcium is also one of those elements that delivers very strong size, but has.

A synergistic relationship with cytokinin and increases overall reproductive energy.

Unlike the other vegetative elements, Manganese, of course, is very strongly correlated with cytokinins.

Activity and with reproductive bud initiation.

We very clearly see that when plants.

Have adequate levels of manganese, we get very strong bud count.

And it's fairly easy, relatively easy on.

Most crops to significantly increase the number of buds if we so desire, by making sure that plants have an abundance of manganese.

And we also need boron.

Boron also has a synergistic relationship with.

Cytokinins as well as with calcium, and helps to facilitate the transport of calcium into the furthest buds.

So if you have a crop such.

As, let's say, tomatoes, where you have.

A cluster of fruit and the furthest flowers are often significantly weaker than the flowers closest to the base, and you have a wide range of bud size and uniformity, Boron is one of the elements that helps increase that uniformity and bring those opposite ends of the spectrum.

Closer together the most rapidly, because it.

Really helps to move calcium and other nutrients out to the farthest buds very quickly and very aggressively. Zinc also contributes significantly to size.

There's a direct correlation between the quantity.

Of zinc and overall bud size, overall leaf size.

And zinc is also very important for.

All of the spur bearing trees. So we know that a significant quantity of the sugars that move into the fruit on a fruiting spur, on, let's say cherries or apples, is produced by the spur leaves.

So that means we need to have.

The largest spur leaf size possible.

And to get large spur leaves, we.

Need to have large vegetative buds as well as reproductive buds in the fall.

And that is accomplished by making sure.

That we have adequate levels of zinc.

Going into those buds in the fall. And copper also becomes Very important because copper stored in the bud contributes to.

The future of pollination strength.

If you have a variety or a.

Strain that does not pollinate very well, making sure you have adequate levels of copper, in addition to all these other.

Pieces that we've identified, usually has a.

Significant impact on that problem because it increases pollen strength and pollen tube strength.

Lastly, for the growers who are not.

Organically certified, a foliar application of urea.

Can have a very significant effect on perennial crops, specifically who are triggering reproductive bud initiation in the fall. The idea is that when we put.

On a very late application, foliar application of urea, as the plant is already senescing, the urea will be absorbed by.

The leaves and transported to the buds. The plant is already shutting down.

So much of that urea actually gets stored in the bud in the form of urea, not in the form of nitrates or ammonium.

This is really significant because in the form of urea it has a very high salt index, which increases the freezing.

Resistance and lowers the freezing susceptibility for those buds and also of course, gives.

Them a very those buds very strong.

Growth energy push the following spring and they emerge from dormancy very quickly.

Seaweed is known to have many positive.

Impacts for reproductive bud initiation. Increasing the number of buds, the size, the health, the vigor. It's become so widely known for this benefit and so widely used from so many different growers and companies that it's.

Not that even there's a long list, a long range of benefits that seaweeds provide, including hormonal support, etc.

A longer list than is necessary worthwhile going into in this conversation. So when we look at the list.

The critical nutrients to manage in the.

Weeks just prior to reproductive bud initiation.

Is this list of these seven nutrients. Calcium, manganese, boron, zinc, copper, urea and seaweed. If you are an organic producer and.

Not able to use urea, then ultimately of course the goal is to have.

Soils with such abundant microbiology supplying such abundant nitrogen in the form of amino.

Acids to the plant that we don't.

Need to add any nitrogen. And this is a reality for some.

Organic growers, but not for all.

Many growers would still benefit from replacing.

This urea with a foliar application of amino acids. So there are now dry water soluble amino acid powders available that can be used for a shot of nitrogen into the bud.

The amino acids have a slightly different.

Effect from the urea.

They don't contribute to the freezing resistance that the urea does, because they don't.

Have the high salt index, but they do still contribute to the uniform bud size and the vigor as they emerge from winter dormancy. So that's still a very valuable addition. The second critical point of influence that.

We look at is blossoming and pollination.

And.

When we look at what are.

The factors that we can influence.