A study investigating how lignin-based nanoparticles can keep pesticides from degrading in sunlight is continuing in Cristina Sabliov’s lab. Sabliov, a professor in the Department of Biological and Agricultural Engineering, has been conducting research on lignin-based nanoparticles for several years.

This year her research focuses on whether nanoparticles with entrapped fungicides can improve disease control, plant stands and yields.

“The goal is to take a natural agrochemical and entrap it in nanoparticles such that you can protect it from UV degradation with the help from lignin,” Sabliov said.

The nanoparticles would help to keep the agrochemical effective longer, allowing soybean producers to spray their fields less often, saving costs and reducing environmental effects.

Sabliov has been working with the agrochemical azadirachtin. Entomology graduate student Celeste Mejia Gonzalez, working under the direction of entomologist Jeff Davis, is carrying on the research to see if the formulation works both in the lab and in the field.

This year, Gonzalez was using five different treatments on the soybean plants in the field in addition to the untreated control — lignin with just the polymer, poly(lactic-co-glycolic) acid or PLGA, lignin PLGA with neem oil, just neem oil, and the azadirachtin product, AzaMax.

“We spray the soybeans and collect soybean leaf tissues at the top of the plant and two center rows at four different times — zero days after treatment, two days after treatment, seven days after treatment and 14 days after treatment,” Gonzalez said.

The leaves are brought into the lab and placed in petri dishes with soybean loopers. Gonzalez checks them for five days to see the feeding behavior and mortality of the loopers.

“We found that mortality declined over time in all treatments, but lignin-PLGA neem oil showed the highest and most consistent residual effect,” Gonzalez said.

She also found that the pure neem oil had strong immediate toxicity, but lost efficacy rapidly and the AzaMax provided moderate stable control.

Sabliov said the study demonstrates that the nanoparticles are having their anticipated results — the agrochemical entrapped in the nanoparticle lasted longer in the field.

The research will also look at plant growth, plant stands and yields throughout the soybean growing season.

Also working on this research is biological and agricultural engineer Carlos Astete and plant pathologists Trey Price and Vinson Doyle.