Cellulosic nanomaterials (CNMs) are green nanomaterials that are synthesized from organic or renewable sources. These nanomaterials exhibit exceptional physical and chemical properties such as biocompatibility and mechanical strength, owing to which they have various uses in agriculture and the nutraceutical industry. Recently, CNMs have been reported to be the solution to the problem of herbicide drift, which causes immense financial loss in the agriculture sector. This article discusses how CNMs solved the problem of herbicide drift faced by farmers.
Herbicide drift results in damage to desirable or non-targeted plants. Image Credit: Sleepy Joe/Shutterstock.com
What is Herbicide Drift?
Herbicides are chemical components that are used to remove or kill unwanted plants that grow in agricultural and ornamental fields. However, when herbicides are applied inappropriately, they cause damage, with slight to severe symptoms, to the desirable or non-targeted plants. Farmers suffer a significant economic loss due to such herbicidal malpractices. The characteristic physical and chemical properties of herbicides determine their mode of activity on the plant system. Additionally, certain factors such as soil content and texture, soil moisture, plant size, temperature, and relative humidity, play a vital role in the efficacy of a herbicide.
Herbicide drift is defined as the physical movement of herbicides through the air. Drift occurs during the application or soon after its application from the targeted site to the non-targeted site in three different ways, i.e., physical spray-particle drift, vapor drift, and herbicide-contaminated soil.
Physical spray-particle drift involves the movement of fine droplets that are generated when herbicides are applied using narrow nozzle tips at high pressure. These spray droplets may travel a few feet to several miles from the targeted area depending on the weather condition and the nozzle tip of the applicant. However, the potential damage caused by this type of herbicide drift is less because droplets get diluted in the atmosphere. Vapor drift refers to those herbicides that vaporize and mix freely with air. Two of the main factors on which this kind of herbicidal drift depends are the volatility of formulation and weather conditions.
Examples of herbicides that may drift in vapor form are dicamba, clopyralid, and triclopyr. Researchers have also stated that herbicides may move from a treated site by clinging to soil particles and drifting as herbicide-contaminated soil. The soil may get contaminated when herbicides are directly applied to the soil or when herbicides may wash off after a foliar application by rain or overhead irrigation.
Scientists have proclaimed that awareness is the key factor for preventing herbicide drift. The applicator must pay heed to possible consequences if misused. For example, before using a herbicide, the applicator must know the vicinity of susceptible crops and the weather conditions, particularly the wind speed and direction.
Cellulosic Nanomaterials - A Solution to the Herbicide Drift Problem
Two researchers, namely, Joseph Batta-Mpouma, and Gurshagan Kandhola, have developed a solution to the problem of herbicidal drift. Batta-Mpouma is a doctoral candidate in the Materials Science and Engineering program at the University of Arkansas. At present, he is a senior research assistant to Jin-Woo Kim, Professor of Biological and Agricultural Engineering at the Agricultural Experiment Station, University of Arkansas’s College of Engineering. Kandhola is a post-doctoral research fellow in Kim’s research group. Both of the researchers have collaborated in a commercial project related to nanocellulosic technology for herbicide drift control.
Batta-Mpouma stated that every year the Environmental Protection Agency has estimated a loss of around 70 million pounds worth of herbicides in the environment, in the United States, owing to herbicide drift. To keep the herbicide at the targeted site, Batta-Mpouma and Kandhola have created a unique formulation of biodegradable nanomaterials which has been derived from cellulosic waste, e.g., sawdust. This formulation acts as an adjuvant and is mixed with the herbicide spray mixtures which can effectively reduce herbicide drift. This project received the University of Arkansas Chancellor’s Fund grant for the advancement of this technology.
Professor Kim has been involved with developing new applications from nanoparticles directed in the field of medicine, agriculture, and many other commercial uses. For developing nanomaterials, he uses nano-building-block (nBLOCK) technology to influence the self-assembly of nanoparticles into particular shapes for specific purposes. According to Batta-Mpouma, when he became aware of volatilization and drifting of dicamba-based herbicides in Arkansas farm fields, he believed the nBLOCK technology could be applied to solve the problem.
Batta-Mpouma and Kandhola used Kim’s nBLOCK technology (nano-toolbox) to develop a cellulosic crystal nanoparticle to bind to herbicides (adjuvant). This cellulosic crystal nanoparticle has been named BioGrip™ which serves as an agrochemical encapsulating carrier. When this newly developed cellulosic nanomaterial is mixed with herbicides, it adds weight to the herbicide droplets, as a result of which, during field applications, it falls quickly and more directly on the targeted site. Additionally, it prevents volatilization of the active ingredient and remains adhered to the weeds.
Both the researchers realized that their product has a potential commercial application, for which Batta-Mpoum joined a Research and Commercialization course offered by the University of Arkansas’s Walton College of Business. Following this, they founded a new company called CelluDot LLC. Batta-Mpouma acts as standing chief executive officer and Kandhola serves as a chief technology officer of the company.
The researchers received further grants which enabled them to optimize their formulation and conduct more experiments to validate their research and proceed towards the goal of commercializing the product. Bryan Renk, director of technology commercialization at the Division of Agriculture has filed for a patent on the newly designed product and also opted for intellectual property rights to CelluDot.
References and Further Reading
Khan, A. et al. (2018). Cellulosic Nanomaterials in Food and Nutraceutical Applications: A Review. Journal of Agricultural and Food Chemistry, 66 (1), pp. 8-19. https://doi.org/10.1021/acs.jafc.7b04204
Al-Khatib, K. (2021). Herbicide Damage. The University of California. [Online] Available at: http://herbicidesymptoms.ipm.ucanr.edu/HerbicideDamage/
Cellulosic nanomaterial may help solve problem of herbicide drift. (2021). Stuttgart Daily Reader. [Online] Available at: https://www.stuttgartdailyleader.com/cellulosic-nanomaterial-may-help-solve-problem-of-herbicide-drift/