Frances Gould, Blanchard, Tobie M. | 10/14/2016 5:39:36 PM
An ongoing study testing the use of nanoparticles to deliver insecticides is producing positive results. Cristina Sabliov, a scientist in the LSU AgCenter Department of Biological and Agricultural Engineering, and Jeff Davis, an LSU AgCenter entomologist, have shown that insecticides embedded in nanoparticles — tiny particles 1,000 times smaller in width than a human hair — have improved the effectiveness of insecticidal efficacy.
Sabliov, who has worked with nanoparticles on other projects, creates the particles for this project in her lab with research professor Carlos Astete. The particles are made out of zein, a biodegradable corn-derived protein.
Davis tested the nanoparticles with the insecticide methoxyfenozide for two years on soybean plants. This year he is using the insecticide chlorantraniliprole. He is looking at the insecticide’s ability to control soybean loopers.
So far, the research has shown that nanoparticles increase the efficacy of the insecticide.
“Particles stick to the surface and release chemicals for a longer period of time,” Sabliov said.
Sabliov also was able to confirm the presence of the nanoparticles on the leaves by dipping the leaves in a compound of fluorescently-tagged nanoparticles for 15 minutes, then quantifing the amount of fluorescence in the plant.
Improving insectical persistence on the plant offers more protection against the soybean looper, a pest that feeds on the leaves.
“The soybean looper can defoliate a plant,” Davis said. “Without leaves, the plant can’t undergo photosynthesis.” This can lead to pods that won’t fill with seeds and a decreased harvest.
The researchers also were able to see the effects of the insecticide entrapped in nanoparticles by feeding insecticide-treated leaves to soybean loopers. Davis said they fed the loopers leaves with just nanoparticles, fed them leaves with just the pesticide, and fed them leaves with the pesticide entrapped in the nanoparticles.
“The nanoparticles alone did nothing” Davis said. “The pesticide alone killed insects, but it only lasted for about 14 days.”
The results showed the nanoparticles with insectide killed insects for 21 days.
“So growers would get an extra week of coverage, which could make a difference in yield and reduce the need for additional insecticide applications,” Davis said.
With longer lasting insecticides that adhere better to the leaf surface, growers can use less of the chemical on their crops. Sabliov and Davis said this can help farmers save money and is better for the environment. The researchers said this technique may be applicable to other products, such as fertilizer, fungicides and herbicides — but more research would be necessary. Tobie Blanchard