Alyssa Butler – Soybean Science Challenge Winner Virtual FFA Arkansas State Agriscience Fair

Alyssa Butler, Carlisle High School, Carlisle, AR

Mentor: Carly Bokker

Category: Plant Sciences

Project Title: Greenhouse host resistance rate study on soybean cultivars
to southern root-knot nematode

Abstract:
The southern root-knot nematode (Meloidogyne incognita) is one of the most important yieldlimiting plant-parasitic nematodes that affect soybeans (Glycine max) in Arkansas. One of the best management tools that farmers have is host resistance; however, limited information about the host is available. The objective of this study is to evaluate host resistance to different inoculation rates of southern root-knot nematode. Plants were planted in a split plot design with a factorial arrangement of nematode inoculum rates and soybean cultivars. There were five replications per inoculum rate x soybean cultivar. Soybean cultivars that have proven resistant to root-knot nematodes (Pioneer P45A29L and Pioneer P46T59R), along with one susceptible check (Delta Grow 4880) were used to test nematode resistance and egg reproduction. Each cultivar was artificially inoculated 14 days after planting (DAP) with 10,000 and 20,000 eggs. Soybeans were rated at 48 days after inoculation, roots were processed to determine eggs per gram root, and egg reproduction was calculated. There was no inoculum rate interaction within varieties for eggs per gram of root; however, there was a cultivar interaction. One of the resistant cultivars had a significantly lower eggs per gram root at the lower inoculation rate when compared to the susceptible check at the higher inoculation rate. There was also an inoculum rate x soybean cultivar interaction for egg reproduction factor. The Liberty Link Pioneer cultivar at both inoculation rates and the Roundup Ready Pioneer cultivar at the higher inoculation rate were statistically different when compared to the lower inoculated susceptible check for egg reproduction factor. Pioneer P45A29L and Pioneer P46T59R showed to have lower egg reproduction when inoculated at higher nematode levels when compared to the susceptible check and would be good choices for farmers’ fields with damaging populations of southern root-knot nematodes