Diminished control of goosegrass was observed in tomato fields located in Manatee County, FL, after years of repeated paraquat use. Tolerance of the Manatee biotype to paraquat was confirmed by its comparison in greenhouse studies with a susceptible biotype from the Alachua County, FL. A 30-fold increase in paraquat rate was required to reach the 50% growth reduction level of the resistant biotype over the susceptible biotype. The Manatee biotype was not tolerant to clethodim, metribuzin, or sethoxydim. These herbicides provided adequate control of all the goosegrass biotypes tested.

Mulches have been evaluated extensively as a weed management tool in container plant production, but most research has focused on loose-fill wood-derived mulch materials, such as pine bark or wood chips. In this experiment, pine (mixed Pinus sp.) bark (PB), shredded hardwood (HW), and pine sawdust were evaluated for weed control and crop response both alone and in combination with a guar gum tackifier alongside a plastic film mulch, a paper slurry mulch, and the paper slurry mulch + PB and compared with a nonmulched, nontreated control and a single application of preemergence herbicide (oxyfluorfen + pendimethalin). Mulch materials were applied to nursery containers ranging from 7 to 25 gal at two different nurseries and at two research centers in central Florida in 2017 and 2018. Results showed that the plastic mulch provided more than a 90% reduction in hand weeding time and weed weight over a 6-month period, and similar control was achieved with PB, paper slurry + PB, and the HW treatment (64% to 91% reduction in weeding time and weed weight). No growth differences were observed with any mulch treatment in any species evaluated including ligustrum (Ligustrum japonicum), Chinese elm (Ulmus parvifolia), or podocarpus (Podocarpus macrophyllum).

Mulches have many positive benefits for the production of plants, ranging from weed suppression to water conservation. In this study, a novel method of using plastic film mulch for container-grown plants was evaluated. Plots of 25 japanese privet (Ligustrum japonicum) in #1 (2.5 qt) nonspaced containers were wrapped with 1.25-mil white or black plastic mulch over the top and sides of containers. Small plants were planted through the plastic and grown for 22 weeks with overhead irrigation. Water application amount was determined by moisture sensors placed in the substrate of each treatment. Plant growth, dry weights (DWs), weed fresh weights, weeding time, substrate electrical conductivity (EC), substrate temperature, total water applied, and mulch costs were determined. Black plastic (BP) and white plastic (WP) mulch reduced water applied by 82% and 91%, respectively, compared with the nontreated control (NT). Nontreated control plants grew faster and had greater DW at the end of the experiment. Mulched containers had fewer weeds and required less labor to remove weeds than the NT treatment. Substrate EC level was greater in BP and WP treatments than for the NT after 20 weeks, and plastic mulch did not result in different substrate temperatures. Plastic mulch added $4.94/1000 containers ($2.24 input cost and $2.70 removal cost) to production costs, not including disposal costs. This novel method of mulching nonspaced plants reduced irrigation water, herbicide applications, and weeding labor, but probably added 2–3 weeks to finish time.

This article discusses management of liverwort in ornamental plant production. Liverwort is a unique weed species that poses special challenges for growers in terms of management. This article is the result of numerous consultations with FL growers seeking advice on management options for this species in nurseries, containers, and in greenhouses and other production areas.

Rose mosaic virus disease is one of the most economically important diseases affecting roses, because a single symptomatic leaf can result in the rejection of complete shipments for wholesale or retail rose producers. It continues to be a problem in nursery production and landscapes. This 5-page document discusses the causes, symptoms, and management of this disease. Written by Susannah da Silva, Binoy Babu, Mathews L. Paret, Gary Knox, Fanny Iriarte, Barron Riddle, Matt Orwat, Shawn T. Steed, E. Vanessa Campoverde, and Svetlana Y. Folimonova and published by the UF/IFAS Plant Pathology Department, August 2018. http://edis.ifas.ufl.edu/pp338/