Humans have been cultivating cotton for millennia. In fact, evidence points to independent development of cotton crops in South America1, Northern Africa2, and the Indian subcontinent3.
Not only is cotton used in clothing and home goods such as towels and sheets, its is also used in medical supplies, wallpaper, books, and thread4. And, because of its ubiquity, there’s pressure to ensure demand is met.
Cotton is a very particular plant when it comes to the weather. It likes the sun and can't stand frosts; summer temperatures need to be higher than the mid-70s, with plenty of rain (or irrigation) in the germination and growing seasons. Today, the top producing cotton producing countries are:
- China (35.8M bales a year)
- India (23.8M)
- Brazil (19.5M)
- United States (13.9M)
- Pakistan (5.3M)5
Cotton industry challenges
As with many crops, cotton is faced with challenges due to climate change. Rising temperatures, alterations in water availability, and increased attacks from pests will force growers to evaluate their farming practices.
In addition, uncertainty around tariffs and global supply chains can erode cotton’s profitability as a cash crop.
Finally, continuous cotton cropping has caused soil in some regions to lack enough nutrients to achieve maximum yield. Cotton is sensitive to nitrogen, potassium, sulfur, and boron deficiencies soil6. Boron is recognized as the most important micronutrient for cotton production and is the crop's principal limiting nutrient factor.
No amount of any other fertilizer can produce so significant an increase in productivity. When the plants are growing and fruiting vigorously, they are also better able to naturally resist the attentions of voracious boll weevils and pink boll worms.
What does boron deficiency in cotton look like?
It is rare for a cotton crop to show any visible symptoms. Plants can look perfectly healthy, but the yield of fiber (lint) is severely depressed7. And, with every season that goes by, the boron available from the soil depletes as it is used up by the crop.
Visible symptoms include:
- Flower and boll shedding
- Bands (often excessively hairy) on petioles
- Terminal bud death
- Lateral branches with short internodes and enlarged nodes
- Excessive and abnormal vein development with buckled and irregularly shaped leaves
See pictures of boron deficient cotton
Testing for nutrient deficiencies in cotton
The best way to correct boron deficiency in cotton is to prevent it in the first place. Regular soil testing for nutrient deficiencies can be scheduled when you take samples for nematodes.6 Having this data will make it easier to plan your fertilization program.
Treating a boron deficient cotton field
The amount of boron you apply depends upon your specific conditions, but typically you need very little to see improvement. Boron demand is the greatest during lint and seed development. Check with your local agronomist before making changes to your fertilization schedule.
U.S. Borax offers a number of refined borate fertilizers that could benefit your crop.
- Granubor®: Ideal for dry blends that are applied broadcast preplant or sidedressed.
- Fertibor®: Fertilizer suspensions for preplant broadcasts, sidedressing, or band sprayed over the pre-emergent seed row
- Solubor®: Flexible application can be dissolved alone in water or in liquid fertilizers and/or pesticides and then applied to the soil or directly onto the foliage
If you have questions about which U.S. Borax product is right for your field, contact our local agriculture experts.
References
1. Splitstoser JC et al. 2016. Early pre-Hispanic use of indigo blue in Peru. Science Advances 2(9).
2. Allaby R. 2012. Ancient Egyptian cotton unveils secrets of domesticated crop evolution. University of Warwick.
3. Moulherat C et al. 2002. First Evidence of Cotton at Neolithic Mehrgarh, Pakistan: Analysis of Mineralized Fibres from a Copper Bead. Journal of Archaeological Science. 29(12):1393-1401.
4. Cotton: From Field to Fabric. accessed 2026. National Cotton Council of America.
5. Production - Cotton: Top Producing Countries. 2025/2026. US Department of Agriculture: Foreign Agricultural Service.
6. Gatiboni L and Hardy DH. 2023. Cotton Information: Chapter 7. Fertilization. NC State Extension at North Carolina State University. p. 40-53.
7. Rosolem CA and Bogiani JC. 2011. Physiology of boron stress in cotton. In Ooosterhuis, ed. Stress Physiology in Cotton. Cordova(TN). The Cotton Foundation. p. 114-124.
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