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Core Ideas• Cereal rye and wheat cover crops produced similar levels of biomass as a multi-species mix.• A preemergence herbicide was required to achieve acceptable, consistent levels of weed control.• Cover crop treatment did not significantly impact soybean yields.• A wheat-soybean double crop system reduced soybean yields in four of five site-years. AbstractThe integration of cover crops into soybean (Glycine max) production has many potential benefits, but little information has been collected on the impact of multiple-species cover crops on the subsequent soybean crop relative to the common wheat (Triticum aestivum)soybean double crop. Experiments were established at the West Tennessee Research and Education Center in Jackson, TN in the fall of 2014, 2015, and 2016 and the Research and Education Center in Milan, TN in the fall of 2014 and 2015. Winter treatments included a winterfallow, cover crops including cereal rye (Secale cereal), wheat, crimson clover (Trifolium incarnatum), and a five-way mixture [cereal rye, oats (Avena sativa), oilseed radish (Raphanus sativus), crimson clover, and hairy vetch (Vicia villosa), referred to as mix], and wheat for grain.Treatments were split to evaluate weed suppression relative to the preemergence herbicide, S-metolachlor + metribuzin. Largest levels of biomass (commonly 4000+ lb/acre) were associated with the wheat for grain, cereal rye, and mix treatments. Weed control was greatest in cereal rye, wheat for cover and mix treatments, but no treatment provided consistent, acceptable weed control without the use of the preemergence herbicide. Soybean yields were not impacted by cover. The delayed planting of soybeans after wheat for grain negatively impacted yields in four of five site-years by an average of 20 bushels/acre. Results suggest impacts of single-or multiple-species cover crops on soybean yields may be negligible. Market prices, incentives, and long-term benefits may be more important than short-term costs/benefits when selecting a production system.

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In August of 2013, garlic bulbs (Allium sativum) of the variety Chesnok Red grown and stored under dry conditions by a commercial producer in Buncombe County showed water-soaked, tan to salmon-pink lesions. Lesions on cloves became soft over time, slightly sunken, and had mycelium near the center of the bulb, which is characteristic of Fusarium rots on garlic (1,2). Approximately 10 to 20% of the bulbs inspected in the drying storage room were affected. Surface-sterilized tissue was excised from the margin of lesions on eight bulbs, plated onto acid potato dextrose agar (APDA), and incubated in the dark at room temperature (21°C). White to light pink colonies with abundant aerial mycelium and a purple pigment were obtained from all samples after 2 to 3 days of incubation. Inspection of colony morphology and reproductive structures under a microscope revealed that isolate characteristics were consistent with Fusarium proliferatum (Matsushima) Nirenberg. Microscopic morphological characteristics of the isolate included hyaline, septate hyphae; slender, slightly curved macroconidia with three to five septae produced in sporodochia; curved apical cell; and club-shaped, aseptate microconidia (measuring 3.3 to 8.3 × 1.1 to 1.3 μm) produced in chains by mono and polyphyalides. To further define the identity of the isolate, the beta-tubulin (Btub), elongation factor 1a (EF1a), and internal transcribed spacer (ITS) regions were amplified and sequenced (3). The resulting sequences were compared against the GenBank nucleotide database by using a BLAST alignment, which revealed that the isolate had 100% identity with F. proliferatum for the Btub, EF1a, and ITS regions (GenBank Accession Nos. AF291055.1, JX118976.1, and HF930594.1, respectively). Sequences for the isolate were deposited in GenBank under accessions KJ128963, KJ128964, and KJ128965. While there have been other reports of F. proliferatum causing bulb rot of garlic in the United States (1), to our knowledge, this is the first report in North Carolina. The finding is significant since F. proliferatum can produce a broad range of mycotoxins, including fumonisins, when infecting its host, which is a concern for food safety in Allium crops. References: (1) F. M. Dugan et al. Plant Pathol. 52:426, 2003. (2) L. J. du Toit and F. M. Dugan. Page 15 in: Compendium of Onion and Garlic Diseases and Pests. H. F. Schwartz and S. K. Mohan, eds. The American Phytopathological Society, St. Paul, MN, 2008. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, CA, 1990.