Skip to main content
Hero Image
Freshly harvested sweetpotatoes laying on soil

ARS Researchers Identify Sweetpotato Varieties Fit to Fight Pests

Two juvenile guava root-knot nematodes
Colorized microscopic image of two juvenile guava root-knot nematodes, one newly hatched and one still unhatched within its ovoid egg. (William Rutter, D5074-2)

In recent years, farmers in the southeastern United States have struggled with the invasive guava root-knot nematode (GRKN), a microscopic roundworm. GRKN infects and damages a variety of crops, particularly sweetpotato, which had historically been resistant to other species of nematode. To combat this worm, ARS researchers at the U.S. Vegetable Laboratory in Charleston, SC, tested sweetpotato lines from the agency’s expansive germplasm collection, which safeguards seeds and other biological material that USDA maintains to ensure the genetic diversity of our food supply.

Within that collection, the researchers were able to identify 20 sweetpotato lines with strong resistance to GRKN. The researchers published their findings, which are already helping sweetpotato breeders at USDA and universities to develop new GRKN-resistant sweetpotato varieties.  Once released, these new varieties will help growers protect their crops from GRKN.

Related Information

Video: Controlling Guava Root-Knot Nematode
Research Project: Biology, Etiology and Host Resistance in Vegetable Crops to Diseases and Nematodes

Explore Other Discoveries

Predicting High-Risk Areas for Wildfires

Researchers developed a forecast tool to determine which areas have the highest probability of a large rangeland fire.

Building a Better Honey Bee

ARS researchers are studying genetics and breeding to make honey bees more resilient.

Long Term Honey Bee Research Monitoring Network

A long-term honey bee monitoring network helps researchers to better understand colony performance and survivorship over multiple seasons.

Plant Diseases Hide Unexpected Places

ARS researchers examined rhododendron plants growing in native stands, looking for microbes that cause diseases that affect other plants.

Screening to Breed Superior Cotton

Scientists are producing new strains of cotton that offer both quality and abundance.

Improved Fall Planting Options

ARS researchers recently developed and released three new pea cultivars that can be grown in the cooler months.

Helping Farmers in South America

Scientists investigated practices that might help smallholder farmers increase sustainability of their lands and adapt to a changing climate.

How Healthy is Your Soil?

Researchers have developed a new, easier way to find the answer to the question, "How much carbon is stored in soil?"

Beneficial Wasp May Put Sting in Fruit Pest

ARS and University of California-Berkeley scientists are evaluating the potential of a parasitoid wasp to control the fruit fly, spotted wing drosophila.

Genes That Keep Tomatoes Fresher

Scientists have identified a tomato gene that's responsible for the softening process in the fruit as it matures, and found a way to inhibit the gene, keeping tomatoes firmer, longer.