This transcript is AI generated; there may be mistakes.
Rooting hormones are an important part of vegetative propagation, and if you aren't using them it could really improve the rooting uniformity of the crops within your trays as well as reduce the shrink or number of plants you're losing in propagation as well.
There's a variety of different products available but mostly what we're using are synthetic auxins or rooting hormones in the greenhouses today.
There are powder formulations as well as formulations that can be mixed into a liquid, as well as liquid formulations that can be applied over the top of cuttings.
Auxin is the phytohormone that causes root development and it's produced in the shoot tip of the plant and transported down through the stem into the root or stem of the plant where roots develop.
IVA or indolebutyric acid is the most common synthetic hormone that we're applying over the top of our cuttings.
NAA and IAA are also common rooting hormones that can be applied within the industry but are less common because they're either insoluble in water or they're mixed with alcohol solvents and that causes damage to foliar tissue on plants.
Powder rooting hormones are very common and have been used for a long time within our industry.
Those are available in a variety of different trade names but basically it's this white powder consisting of the active ingredient or rooting hormone.
To apply this product, you take this cutting and dip the stem into the base, coating it fully like this.
You then stick it into the tray and get good stem-to-substrate contact in order for those roots to grow.
This process can be labor intensive, meaning that we have to touch every cutting and put it into the powder in order to apply the product.
However, almost anyone can do it and the products are readily available.
Liquid formulations on the other hand are a relatively newer addition to our tools within the greenhouse.
This is Hortus KIBA salts, which have been formulated to be able to be mixed with water and sprayed over the top of cuttings.
This is called Advocate and is a liquid IVA rooting hormone as well, which can be applied over the top of cuttings.
These are becoming very popular because you can reduce the amount of labor needed to apply the rooting hormone to cuttings.
You can also apply these products to a large number of cuttings at one time using sprayers like these, even a backpack sprayer.
Mixing liquid formulations of rooting hormones is also very familiar to us because of how we mix our plant growth regulators as well as our fertilizer solutions based on a part per million concentration.
How we apply liquid formulations of rooting hormones is important because the volume that we can apply to the cuttings themselves.
Sprays use a smaller volume of water and are really just meant for the foliar portions of the cutting.
Sprinting is another method of applying these products over the cuttings and is actually preferred because the amount of volume applied to the cuttings is higher.
This allows the solution of rooting hormone to drip down the stem into the substrate where the stem reaches the substrate itself.
This is where we want the rooting hormone to be because this is where roots will develop.
Liquid formulations of rooting hormones can also be used for cutting dips as well, such as here.
Similar to the powder dips, this method will require a different concentration of rooting hormone than compared to our sprays or sprenches, for example.
One thing to keep in mind, especially with liquid formulations of rooting hormones, is that they can cause a lot of phytotoxicity on various crops.
What you'll see is leaf yellowing as well as leaf curl.
I've seen this on Calibrachoa, for example, as well as a number of other crops, so make sure you're testing out the specific rates of rooting hormone that you're using as well as the volume you're applying over your crops before committing to a whole greenhouse of production.
If you're looking for more information on rooting hormones or how to apply these in your situation in the greenhouse, feel free to reach out to us on the Technical Services team anytime or search our website at ballseed.com for rooting hormone information.
You can also reach out to any breeding companies that provide products and culture information as they're often listing the concentration of rooting hormone that you should apply to those vegetative crops in the greenhouse.