Plant growth regulators (PGRs) have gained a solid reputation for good early stand development and enhanced initial crop growth. But what many growers are not yet aware of is how late-season PGR applications can seal the deal on crop yields.
PGRs are a hormone-like chemicals that occur naturally in plants. Also called plant growth regulators, these chemicals are EPA-registered because of their ability to directly affect plant responses.
Early season PGR products play key roles in crop growth by encouraging strong root development and early shoot and branch division.
There’s a lot of early season PGR offerings in the ag retailer marketplace because these products have proven themselves to do a phenomenal job for farmers at getting a new crop off to a good start and establishing a strong and resilient root system. All key to eventual yield success.
But what about applying late-season plant growth regulators later in the season? Would that produce any additional benefits to farmers and growers?
What are Late Season PGRs?
Late-season PGRs are exactly what they sound like − a formulation of plant stimulants that create a plant response that are best applied later in the season because they support the crucial final stages of crop development − specifically fruit and bloom retention and the development of reproductive tissues.
Late-season PGRs may include some chemicals used as early season PGRs but are formulated very differently. Late season plant growth regulators focus explicitly on supporting late-season plant growth. For instance, kinetin is useful for its ability to drive cell differentiation. When kinetin is used early in the season, it increases plant rooting and branching. But when used later in the season, combined with other late-season specific PGRs, supports a plant growing, branching, and setting more flower buds − even in that plant has already started to move into the reproductive stage.
Choline chloride and gamma aminobutyric acid (GABA) are two additional PGRs that are useful in a late season crop application. These two plant stimulants work together to support plants during stressful conditions.
In late summer when conditions typically move toward hot and dry, plants experience stress. Their response is, stop metabolizing and go into stress mode which triggers the stop of active shoot growth and the switch toward reproduction. However, there is still plenty of growing time in the season to be had − if we can convince the plants to keep growing.
Choline chloride and GABA work together to reduce the stress response in plants and support continued photosynthesis. This allows the plant to continue building proteins. But because we have moved into the reproductive period, now those proteins don’t support plant growth, they support reproductive growth. For a grower, the combination of using these three late-season plant growth regulators translates into better grain and pod fill.
Now, late-season PGRs, like kinetin, don’t perform in a vacuum. They should be combined with high-yielding genetics and enough plant-available fertility to meet that potential. But for those growers looking to maximize and retain yield, an application of late season PGRs, like OnWard Max, will optimize their nutrition and genetics programs and enable reaching the ultimate yield potential of a crop.
For more information about OnWard Max and our extensive line of fertility nitrogen-management aids, visit www.agxplore.com/products.
Or are you interested in speaking with one of our on-staff agronomists about the right product for your late season plant growth regulator needs? Fill out our assessment form.