The Mighty Micronutrients Series: Vol. 1 – Boron
Posted Posted Bethany Widman, Research Agronomist on March 03, 2025
There are seventeen essential nutrients that crops require with seven of them being micronutrients. When essential nutrients are discussed by growers and agronomists, the most common nutrients discussed are nitrogen, phosphorus, and potassium. However, it is important not to forget about the additional fourteen nutrients, especially the micronutrients.
Each of these micronutrients are needed in small amounts but they are essential for key functions in plants, hence “small but mighty”. Boron is among the seven micronutrients, which is needed in very small amounts throughout the entire growing season.
Why is Boron Important?
Although boron is needed in trace amounts, it is a key building block for many plant functions such as cell wall formation, flower and fruit development, sugar transport, root development, and nutrient regulation. Here are more details on each of those processes:
1. Flower and Fruit Development
Adequate levels of boron are required to be maintained in crops for good flowering and proper fruit development. Boron helps to enhance the pollen tube elongation that directly impacts fruit development.
2. Nutrient Regulation
Boron is essential for regulating the uptake of other key nutrients like nitrogen, phosphorus, and potassium. This helps to make these nutrients more efficient in the plant, improving overall plant health and optimizing growth.
3. Root Development
The bigger the root mass a crop has, the bigger the area the plant has to absorb nutrients and water in the soil. Boron is key for both root elongation and root hair development. If boron is deficient, the roots will be stunted with fewer hairs, leading to poor water and nutrient uptake.
Spotting Boron Deficiency
Boron is immobile in common crops like corn, soybeans, sugar beets, potatoes, and many more. Boron is immobile in most crops so deficiencies will appear in younger leaves. Boron deficiencies are most common in sandy course soils with high pH values. They can be hard to identify but can be spotted with these symptoms:
Withering and yellowing of the younger leaves
Barron ears and stalks, poor kernel development, short and bent cobs
Yellowing of growing points and leading to death in severe cases
Providing Boron to Crops
Ensuring crops receive enough boron throughout the growing season is essential for proper nutrition. The best approach is to use fertilizers containing boron that can be applied consistently from planting to harvest.
Starters and Sidedress
Including a starter fertilizer that contains boron can help improve root formation and early crop emergence. Boron also enhances the efficiency of other nutrients in the starter, promoting overall plant heath.
Products like MicroMark® DG B or UltraMate® B provide an early- season boron boost, being applied either as a broadcast or banded in furrow. In our 2024 field trials MicroMark DG B outyielded the untreated by 5.42 bu/acre when applied in a broadcast application and by 14.72 when banded in furrow.
Foliars
Foliar applications of boron is an effective way to support crops during the stressful reproductive growth stages. Boron plays a key role in flowering and fruit development, making it crucial to maintain adequate levels throughout the foliar season.
Foliar products like Over Pass® with KOR Technology, Korrect® Plus, or Super 25B® provide a reliable supply of boron to crops. In the past three years of field trials, Over Pass 10-2-10 applied at the R3 growth stage on soybeans has performed very well. This combination of products provides crops with nitrogen, phosphorus, potassium, and boron, helping reduce the effect of midseason stress.
Continue the Conversation with Us
Ensuring crops receive the proper nutrition at every stage of growth is key to maximizing plant health and overall yield at harvest. Incorporating boron through liquid starter, broadcast, side dress or foliar application can provide essential support throughout the season.
To learn more about our boron solutions and how they can benefit your operation, visit us online at https://andersonsplantnutrient.com/agriculture. If you have any questions, our sales and agronomy trams are here to help –reach out today to discuss the best approach to fit your needs.
