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Research Project: Enhanced Alfalfa Germplasm and Genomic Resources for Yield, Quality, and Environmental Protection

Location: Plant Science Research

Title: Understanding disease development in cultivated American wild rice (Zizania palustris) fields

item CASTELL-MILLER, CLAUDIA - University Of Minnesota
item SENAY, SENAIT - University Of Minnesota
item KIMBALL, JENNIFER - University Of Minnesota
item Samac, Deborah - Debby

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/13/2020
Publication Date: 12/30/2020
Citation: Castell-Miller, C.V., Senay, S., Kimball, J.A., Samac, D.A. 2020. Understanding disease development in cultivated American wild rice (Zizania palustris) fields[abstract]. American Phytopathological Society, Plant Health 2020. August 10-14, 2021. p. S2.148.

Interpretive Summary:

Technical Abstract: Wild rice is a native, aquatic species cultivated for its nutritious and gourmet grain. Minnesota industry produces over 9 million pounds of finished grain. Fungicides are an essential component of the disease management system, reducing foliar disease severity (DS) and enhancing grain yield. Tracking disease progression (DP) in fungicide-treated and untreated fields in conjunction with associated environmental variables (EV) can provide information for rational fungicide use. DP in the upper wild rice canopy was recorded under two sprays of an azoxystrobin-based fungicide (F) and an untreated-control (NF) in a RCBD with two replicates at Waskish, Aitkin, and Gully, Minnesota. Leaf samples taken four times during the growing season were used to estimate DS, the area under disease progress curve (AUDPC), and AUDP stairs. From the first to the last sampling times DS increased 13.0% and 5.5% (Waskish), 17.2% and 2.4% (Aitkin), and 22.9% and 7.7% (Gully) in NF and F plots, respectively. AUDPC and AUDPS were significantly reduced under F treatments (P= 0.05). AUDPC in F plots was reduced 2.7-fold (Waskish), 3.2- fold (Aitkin), and 2.3-fold (Gully) compared to the NF plots. AUDPS in F plots was similarly reduced 2.5-fold (Waskish), 4.1-fold (Aitkin), and 2.6-fold (Gully). A multivariate linear regression analysis of EV logged when recording DS showed that temperature and relative humidity had significant effects (R2 = 45%; P = 0.01) on DS whereas dew point temperature did not. Understanding DP and its interaction with EV will allow a more efficient timing of fungicide sprays.