Annual-hill strawberry (Fragaria ×ananassa Duch.) production with black plastic mulch and drip irrigation is gaining popularity in North Carolina. Two experiments (E1 and E2) were conducted on a Wagram loamy sand (Arenic Kandiudult) in 1992 and on a Norfolk sandy loam (Typic Kandiudult) in 1993 to investigate the effects of fall-applied N and spring-applied N and K on `Chandler' strawberry yield and fruit quality. E1 treatments included factorial combinations of banded fall-applied N (0, 34, and 67 kg·ha-1) and drip spring-applied N (0, 0.19, 0.37, 0.56, and 0.75 kg·ha-1·d-1 and 0, 0.37, 0.75, and 1.12 kg·ha-1·d-1 in 1992 and 1993, respectively). E2 treatments included combinations of drip spring-applied N (0.56, 1.12, 1.68, and 2.24 kg·ha-1·d-1) and K (0.46, 1.39, and 2.32 kg·ha-1·d-1 and 0, 0.75, 1.49, and 2.24 kg·ha-1·d-1 in 1992 and 1993, respectively). There were no significant interactions among main effects for any of the measured variables. Market yield maximized with total N at ≈120 kg·ha-1 with one-half banded in the fall and the remainder drip-applied in the spring. Fruit firmness decreased with increasing N rate. Fruit pH and concentrations of total acids and soluble solids were not affected by N treatments, but soluble solids increased as the harvest season progressed. Plant crown number was not affected by N treatment but crown yield increased with N rate similar to market yield. There was no response to drip-applied K for any variable in either year. Based on soil test, fall-applied K (broadcast-soil incorporated) met the K requirements both years.

Poa annua L. is a common component of turfgrass systems both as a weed and a desirable species. Since first classified by Carl von Linné in 1753, nearly 50 taxa of P. annua have been described, with delineations made on the basis of plant morphology and not life cycle. Yet, peer‐reviewed turfgrass literature has recognized only two of these taxa over the past 50 yr, P. annua L. var. annua and P. annua var. reptans, categorizing var. annua ecotypes as upright growing annuals and var. reptans ecotypes as laterally growing perennials. Herein we provide a comprehensive review of peer‐reviewed literature to highlight that these associations between life cycle and plant morphology are flawed given that morphology is plastic and strongly influenced by environment. We conclude by exploring knowledge gaps regarding P. annua perennation that, if addressed through research, would help turfgrass managers better understand the biology of the ecotypes they aim to eradicate or maintain.

Fraise mowing is a maintenance practice that may serve as a non-chemical means of controlling the problematic weed annual bluegrass (Poa annua L.) in bermudagrass (Cynodon spp.) given reports of efficacy on other turfgrass species. However, an understanding of practitioner decision-making in implementing fraise mowing as a weed-control measure remains unknown. A field study was conducted in Knoxville, TN and repeated in space in Jay, FL during summer 2019 to assess bermudagrass regrowth and subsequent annual bluegrass control, following fraise mowing at depths of 1.5 and 3.0 cm compared to a non-treated check (0 cm). Bermudagrass recovered more quickly at the 1.5 cm depth than the 3.0 cm depth and was the swiftest in Florida. Fraise mowing at either depth resulted in a 41–97% reduction in annual bluegrass populations. A qualitative study was conducted in spring 2021, which engaged eight turfgrass managers from Tennessee and Florida via individual interviews in order to understand barriers and challenges to fraise mowing application. Turfgrass managers had positive views of fraise mowing but described challenges in implementation for weed control including cost, labor, area closure, and debris removal.

Soil seedbank management via collecting clippings may be a means of combatting herbicide resistance in annual bluegrass (Poa annua L.) by minimizing recruitment from the deposition of viable seed into the soil. Our objective was to assess the germinability of annual bluegrass seed in spring to determine when collecting clippings would be most impactful. Research was conducted across 2019 and 2020 in five locations: Knoxville, TN; Starkville, MS; Griffin, GA; West Lafayette, IN; and University Park, PA. Annual bluegrass seed was harvested every 100 growing degree-days (GDD 0C ; base 0 ˚C with accumulation beginning on 1 January each year from 400 to 1,100 GDD 0C . Seeds from each harvest timing were placed on moistened blotter paper in petri dishes and randomized in a growth chamber set to a 77:68 ˚F and 8:16 h light-dark cycle. Germination was assessed every 3 d until 21 d of incubation.Cumulative germination percentage after 21 d of incubation increased at research locations in northern latitudes. In Tennessee, germination was greatest from 600 to 900 GDD 0C . In Indiana, germination did not exceed 50% until 600 GDD 0C and increased with GDD 0C accumulation. Clippings should not be collected until at least 600 GDD 0C in these locations. In Pennsylvania, little variation existed among GDD 0C harvest times, indicating that clipping collection may be a valuable practice any time mature seedheads are present. Turfgrass managers should consider geographic location when selecting a time to implement clipping collections and will probably need to conduct multiple clipping collection events. INTRODUCTIONAnnual bluegrass (Poa annua L.; ABG) is a common and problematic weed in turfgrass because of the species' light green color, prolific spring seedhead (inflorescence) produc-Abbreviations: ABG, annual bluegrass; CGP, cumulative germination percentage; GDD, growing degree-days; GDD 0C , growing degree-days with a base of 0 ˚C.

Perennial broadleaves such as dandelion (Taraxacum officinale G.H. Weber ex Wiggers) and white clover (Trifolium repens L.) are known to be pervasive weeds in stands of maintained turfgrasses. The use of synthetic herbicides is the most common and effective method of control for these weeds. As pesticide use in European countries, Canada, and the United States is becoming more scrutinized, identification of alternative weed control options may be necessary. However, few organic or natural weed control products exist. A field study was conducted to evaluate the efficacy of various fertilizers and organic and bio-herbicides including chelated iron, ammonium nanonate, citrus oil, acetic acid, and sodium chloride on dandelion and white clover control as compared to that of two synthetic herbicides containing 2,4dichlorophenoxy-acetic acid (2,4-D), mecoprop-p (MCPP), and dicamba. Injury to perennial ryegrass (Lolium perenne L.) was also evaluated with the objective of determining which products effectively suppressed weed populations while imposing minimal injury to desirable turfgrasses. Chelated iron was effective in controlling dandelion and white clover populations equal to that of both synthetic herbicides with minimal injury to turfgrass. Other organic and bio-herbicide treatments provided some control of both weed populations but generally were too injurious to the turfgrass. Fertility treatments and citrus oil did not reduce populations of either weed. This research indicates that some natural products currently on the market may serve as effective alternatives to synthetic herbicides. This information will be beneficial to homeowners and turfgrass managers controlling weed populations in geographic areas with restricted pesticide use or where control with organic products is desired. INTRODUCTIONWeed populations in maintained turfgrass systems can negatively affect turfgrass health and landscape aesthetics