Boron Roles in Plant Health

May 8, 2023

Trace minerals are very important for plant health and frequently improve the uptake of a macronutrient. In the case of boron, that macronutrient is calcium. Boron improves calcium uptake and translocation. And calcium is incredibly important for crop growth and health! Calcium helps maintain a strong and healthy vascular system through which nutrients and water are taken up from the soil. Calcium is considered the trucker of all minerals – this is one of the reasons. Also, it is interesting that most insects are deterred with higher calcium and boron levels, probably due to adequate pectin structure in the cell walls.

Boron also improves the mobility of magnesium and phosphorus, in both humans and plants. This indirectly means that boron is important for higher brix. But it also has another interesting effect on sugars, which is that it helps metabolize sugars from one form into another. So when plants produce sugars through the photosynthesis process, they are producing glucose. Glucose is then meant to be metabolized into other, more-advanced forms of sugar which are healthier from a long-term prospective. Boron improves the metabolism of these sugars, as evident on brix meters. A healthy plant will produce high brix content during the day. But during the night, the brix should drop several points, if the plant has enough boron, because it is metabolizing the sugars that were produced are metabolized into more advanced forms that are not picked up on the brix meter.

Boron also improves sugar translocation into roots and fruit. For example, boron, along with potassium, stops hollow heart of all crops, such as watermelon for example. Also interesting is that it is almost impossible to get high brix levels if extreme levels of boron are being applied on a continual basis. We suspect that this is due to sugars being sent to the roots too fast. On the other hand, it is impossible to build brix levels without adequate levels of boron.

Boron speeds up plant maturity, along with potassium.

Boron also improves the quality of pollination because it is involved in pollen tube strength. For example: hooked cucumbers are likely a boron deficiency. What happens is that during the pollination process, pollen is sent back through pollen tube. If boron levels are inadequate, the pollen tube will collapse, thus preventing the pollen from fully reaching its destination, resulting in improper pollination. After pollination, boron also improves cell division.

Crops with high boron requirements are root crops (such as carrots and beets), potatoes, celery, apples, pears, grapes, cole crops (such as broccoli, cauliflower, cabbage, and kale), and legumes.

Finally, there is a lot of fear around Boron toxicity. It is true that boron can be toxic, but it also true that boron toxicity is basically a calcium deficiency. In other words, when boron is balanced with calcium, you do not get boron toxicity.

Crops with extra boron sensitivity are cucumbers, raspberries, green beans, strawberries, and also corn to some degree. Also legumes until seeds are sprouted – after sprouting, they do well with higher boron.

In summary, boron is very important. Its roles mostly center on sugar movement and metabolism, and improving the availability of other minerals. Having said that, it is important to keep it balanced, because otherwise, you can’t build brix.