Common bean (Phaseolus vulgaris L.) production worldwide is hampered by Fusarium root rot (FRR), which is caused by Fusarium solani. Screening for FRR resistance on a large scale is notoriously difficult and often yields inconsistent results due to variability within the environment and pathogen biology. A greenhouse screening assay was developed incorporating multiple isolates of F. solani to improve assay reproducibility. The Andean (ADP; n = 270) and Middle American (MDP; n = 280) Diversity Panels were screened in the greenhouse to identify genetic factors associated with FRR resistance. Forty-seven MDP and 34 ADP lines from multiple market classes were identified as resistant to FRR. Greenhouse phenotyping repeatability was confirmed via five control lines. Genome-wide association mapping using ∼200k SNPs was performed on standard phenotyping score 1-9, as well as binary and polynomial transformation of score data. Sixteen and seven significant genomic regions were identified for ADP and MDP, respectively, using all three classes of phenotypic data. Most candidate genes were associated with plant immune/defense mechanisms. For the ADP population, ortholog of glucan synthase-like enzyme, senescence-associated genes, and NAC domain protein, associated with peak genomic region Pv08:0.04-0.18 Mbp, were the most significant candidate genes. For the MDP population, the peak SNPs Pv07:15.29 Mbp and Pv01:51 Mbp mapped within gene models associated with ethylene response factor 1 and MAC/Perforin domain-containing gene respectively. The research provides a basis for bean improvement through the use of resistant genotypes and genomic regions for more durable root rot resistance.

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One pathway by which Palmer amaranth (Amaranthus palmeri S. Watson) invades new areas is through importation of contaminated livestock feed, which then contaminates land‐applied manure. If contaminated feed is suspected, detection tools are needed to test manure, but traditional methods are time consuming and often inconclusive. Although new genetic seed testing is making detection easier, methods to separate seed from contaminated manure are needed. Six methods were compared for their ability to recover 100 Palmer amaranth seeds added to bedded or nonbedded cattle manure: dry sieving, rinse sieving, manure saturation sieving without blending and with blending, and dispersion sieving without blending and with blending. Seed recovery was highest (>90%) with the rinse sieving method regardless of manure type. The dispersion methods are not recommended as they recovered <24.7% of seeds. Following each method, genetic testing successfully identified Palmer amaranth presence, indicating no interference of recovery method with DNA extraction.

Field pea (Pisum sativum L.) root rot has resulted in substantial yield losses in North Dakota, with symptoms ranging from small lesions to complete root destruction. Traditional management practices such as seed treatment fungicides and crop rotation have proven insufficient under high disease pressure. The objective of this research was to determine the efficacy of in-furrow fungicide applications for management of field pea root rot under greenhouse and field conditions. In-furrow fungicides generally reduced root rot severity, sometimes significantly over the seed treatment in the field; however, the level of control varied across hosts and pathogens in both greenhouse and field trials. Prothioconazole, fluopyram, and penthiopyrad provided the most consistent results across trials. The results of these studies indicate that the use of in-furrow fungicides provides growers with another tool for managing Fusarium root rot.

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