• Plant Health
  • Jul 27, 2020

Don't Let a Boron Deficit Compromise Your Corn

Cornfield at sunrise

The growing season has been relatively mild with some periods of challenging weather. Regardless of the weather, boron should always be top of mind as we progress into pollination in corn.


What is the role of boron?

Boron plays a key role in flowering, pollen development and viability, and the pollination process. Most boron is accumulated in the corn plant just prior to pollination to support reproductive growth in tassels and ears.


However, because it is mobile in the soil, boron can leach from the soil profile, especially during wet conditions, which can negatively affect plant uptake and yield potential. A severe boron deficiency may result in a completely barren plant where an ear shoot may not even develop.


What does 2020 tissue sampling data reveal about boron levels in corn?

According to WinField® United NutriSolutions® tissue sampling data from 2020, more than 66% of 2020 corn tissue samples were deficient in or could benefit from a boron application. These results are on-par with sampling data from 2011 to 2018, when results showed that between 55% and 75% of samples were deficient.


Last year, 85% of test samples displayed boron deficiencies due to rain moving high volumes of boron out of the root zone. In 2020, while we haven’t seen the same high levels of deficiency, the consistent lack of boron in samples at this time demonstrates this is often a period when corn needs the micronutrient most. Talk with your agronomist about tissue testing or making a boron application, especially if heavy rains occur in your area.

Nutrient Deficiency Graph

Why is it important to apply boron?

Boron is relatively immobile in the plant until it begins to move to the reproductive parts of the plant during the onset of pollination. As boron moves to the tassel and silks, it becomes deficient in the leaf tissue. Since one of boron’s other jobs is to move sugars and starches from photosynthesis throughout the plant, this deficit during the beginning of reproduction means the plant runs a risk of less efficient sugar transport to newly formed embryos. Fixing a boron deficiency can help the plant optimize photosynthesis as well as sugar transport, which are both necessary for corn plants to thrive.


What could an application of boron do?

Targeting boron at the leaf tissue can help mobilize sugars and feed the newly fertilized kernels in the beginning stages of blister and milk. Boron also helps with flowering set and fruiting while playing a role in pollen survivability and silk rigidity. And boron helps organize cell structure, particularly in the xylem and phloem — the “transportation highways” of the plant. This organization can help increase cellular activity and boost nitrogen efficiency and carbohydrate metabolism.


When should I apply boron?

Boron should be applied between the late vegetative and R1 growth stages to optimize efficacy. Micronutrients like MAX-IN® Boron can be applied on corn between VT and R1 at a rate of 12 to 16 fl. oz. per acre. Such foliar applications can help improve the boron status of corn and reduce the potential for yield loss.


What else can I use in my tank mix?

MAX-IN Boron can be tank mixed with fungicides as well as with adjuvant technologies such as MasterLock® adjuvant. However, be sure to read and follow fungicide label instructions before applying between the V8 and VT growth stages. MAX-IN Boron can also be tank mixed with insecticides. Consult your agronomist to ensure you are applying the correct tank-mix partners at the correct rates and at the optimal times.


Don’t let a treatable boron deficiency take a toll at harvest. Work with your locally owned and operated WinField United retailer now to manage nutrients so you can harvest the kind of corn crop you’ve worked so hard to achieve.

Editor’s Note: This article was originally published in August 2019 and was last updated in July 2020.

All photos are either the property of WinField United or used with permission. 

Important: Before use always read and follow label instructions. Crop performance is dependent on several factors many of which are beyond the control of WinField United, including without limitation, soil type, pest pressures, agronomic practices, and weather conditions. Growers are encouraged to consider data from multiple locations, over multiple years, and be mindful of how such agronomic conditions could impact results.

© 2020 WinField United. MasterLock®, MAX-IN®, NutriSolutions® and WinField® are trademarks of WinField United. 

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