Lesser celandine (Ranunculus ficaria) is an ephemeral perennial introduced to North America from Europe for ornamental use. This species is becoming widespread in shady, moist woodlands and lawns in the northern United States and southern Canada. Despite its invasive attributes, lesser celandine continues to be marketed by the nursery sector. A hardy and easy plant to grow, lesser celandine has a dense compact growth form that makes it ideal for border plantings and showy flowers that make it a desirable garden species for early spring color. The species easily escapes cultivation, colonizing primarily moist woodland habitats. Once established, lesser celandine creates a monoculture and is purported to displace native ephemeral species. Several factors make control of lesser celandine difficult, including a large root structure, which facilitates clonal reproduction and spread. The ephemerality of lesser celandine results in a relatively brief window in which to apply control measures. Land managers need to be aware of this common garden species as a potentially invasive weed and need to be able to differentiate it from the similar native marsh marigold. Effective management strategies are needed to protect native woodland understory species and biodiversity in natural and seminatural areas of affected regions.

Industrial hemp (Cannabis sativa L.) has recently been reintroduced as an agricultural commodity in the United States, and, through state-led pilot programs, growers and researchers have been investigating production strategies. Diseases and disorders of industrial hemp in the United States are largely unknowns because record-keeping and taxonomy have improved dramatically in the last several decades. In 2016, North Carolina launched a pilot program to investigate industrial hemp, and diseases and abiotic disorders were surveyed in 2017 and 2018. Producers, consultants, and agricultural extension agents submitted samples to the North Carolina Department of Agriculture and Consumer Services Agronomic Services Division (n = 572) and the North Carolina Plant Disease and Insect Clinic (n = 117). Common field diseases found included Fusarium foliar and flower blights (Fusarium graminearum), Fusarium wilt (Fusarium oxysporum), and Helminthosporium leaf spot (Exserohilum rostratum). Greenhouse diseases were primarily caused by Pythium spp. and Botrytis cinerea. Common environmental disorders were attributed to excessive rainfall flooding roots and poor root development of transplanted clones.

Bittercress (Brassicaceae) is one of the most prolific and costly weeds of the container nursery industry. Bittercress accessions from container nurseries throughout the major production zones in the United States were examined and compared with herbarium specimens. The identity of these weedy bittercress species were further explored using sequences of the nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) region and the nrDNA region for the COP1-interacting protein 7 (CIP7). Four species of bittercress were detected in the nursery industry of the United States, including New Zealand bittercress, hairy bittercress, flexuous bittercress, and little bittercress. The taxon referred to here as Cardamine flexuosa With. (flexuous bittercress) likely contains two genotypes previously reported as European C. flexuosa and Asian C. flexuosa. Phylogenetic relationships between the four species we examined, particularly in relationship to flexuous bittercress, were not fully resolved by the molecular evidence generated for this study. New Zealand bittercress is nonnative and does not appear in current keys to the species for the United States. Flexuous bittercress is also an alien species, which appears in some U.S. keys but not in all. To aid nurserymen and botanists in identification of these four closely related bittercress species, a key was developed and is accompanied by detailed descriptions and illustrations.

Planting date can affect crop yield and is an important management decision for practitioners. Although wheat (Triticum aestivum L.) and soybean [Glycine max (L.) Merr.] can be effectively double-cropped in North Carolina, if commodity prices and projected economic returns are higher for crops other than soybean, growers might consider a nontraditional, double-crop system. Direct comparisons of major agronomic crops with different planting dates or in a double-crop system with wheat are limited in North Carolina. Therefore, research was conducted in North Carolina from 2013 through 2017 to determine yield potential of corn (Zea mays L.), cotton (Gossypium hirsutum L.), grain sorghum [Sorghum bicolor (L.) Moench], peanut (Arachis hypogaea L.), and soybean planted at two dates within the recommended planting window for full-season production versus planting these crops after wheat harvest.The experimental design was a split plot, with summer crop serving as the whole plot unit and planting date within a crop serving as the subplot unit. Yield of corn, cotton, grain sorghum, peanut, and soybean in full-season production exceeded that of double-cropping with wheat in 5, 5, 2, 4, and 5 yr out of 5 yr of the study, respectively. Estimated economic returns were generated using the 10-yr average (2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017) summer crop prices with the 10-yr average wheat price. When considering all possible combinations of years and crops (n = 25), in only 20% of the possible combinations was the economic return of the double-cropping system greater than economic return of full-season crop production when compared with at least one of the planting dates within the traditional planting window. 1972wileyonlinelibrary.com/journal/agj2 Agronomy Journal. 2020;112:1972-1980.

Field experiments were conducted from 2017 to 2019 to determine the tolerance of carinata to several preemergence and postemergence herbicides. Preliminary screenings identified herbicides which caused large variation on carinata injury, indicating the potential for selectivity. Dose-response field studies were conducted to quantify the tolerance of carinata to select herbicides. Diuron applied preemergence at rates of 280 g ai ha−1 or above reduced carinata population density 54% to 84% compared to the nontreated control. In certain locations, clomazone applied preemergence caused minor injury with an acceptable level of carinata tolerance and only doses above 105 g ai ha−1 caused yield reductions. Napropamide doses of 2,856 g ai ha−1 or higher applied preemergence caused at least 25% injury to carinata; however, the damage was not severe enough to reduce yields. Simazine applied postemergence at rates above 1,594 g ai ha−1 caused 50% or more injury, resulting in yield losses ranging from 0 to 95% depending on location. Clopyralid applied postemergence at 2,512 g ai ha−1 caused 25% injury with relative yield reductions which varied across locations. The present study identified clomazone and napropamide applied preemergence, and clopyralid applied postemergence as potential herbicides for weed control in carinata. In contrast, diuron, simazine, metribuzin, imazethapyr, and chlorimuron caused high levels of carinata mortality and can be used to control volunteer carinata plants in rotational crops.