2011 Annual Report 1a.Objectives (from AD-416) Objective 1: Develop chemical control measures for weeds in ornamental vegetables, fruits, and specialty crops. [NP 304, C2, PS 2B] Objective 2: Determine the response of crops to herbicides to support new pesticide registrations in minor acreage crops. [NP 304, C2, PS 2B] 1b.Approach (from AD-416) Herbicides, alone or in combination with other herbicides or with cultural and mechanical weed control methods, will be evaluated under field conditions to determine weed control and crop responses. The research conducted in this project is part of the national effort of ARS to generate information supporting the registration of minor use pesticides in cooperation with the national IR-4 program. Replaced 0500-00007-078-00D (8/10). 3.Progress Report Research was conducted to develop new pest control tools in ornamental crops, which is often not cost effective for industry, leaving a shortage of available tools for growers of horticultural crops to use. The ARS, IR-4 unit at Prosser, WA and Northwest Horticulture, Mabton, WA cooperated to collect and submit data required to establish registrations for nine new herbicides based on 51 field trials. Completed trials include oxyflourfen + prodiamine, flumioxazin, sulfentrazone + prodiamine, sulfentrazone, dimethenamid-p + pendimethalin, mesotrione, trifluralin + isoxaben, sulfosulfuron, and dimethenamid-p tested on 30 plant species (Cinquefoil, rose, burning bush, sage, sedge, sedum, liatris, Western red cedar, pincushion flower, coreopsis, butterfly bush, Phlox paniculata, purple coneflower, boneset, Western hemlock, Japanese spurge, lobelia, Southwestern white pine, speedwell, Artemisia, creeping phlox, creeping thyme, delphinium, geranium, hyssop, dianthus, lamium, Douglas fir, Fraser fir, and daylily). The completed research will support new registrations of these herbicides in the tested ornamental crops. 4.Accomplishments 1. Determined the response of thirty ornamental plant species to nine new herbicides. The crop safety of the herbicides on these species was previously unknown. Field tests were conducted by ARS scientists in the Vegetable and Forage Crops Research Unit in Prosser, WA on thirty container grown ornamental species. Data generated will be used to support registrations of these herbicides on new ornamental species. This research will aid in development of pest control for ornamental plants.