Ontario. As a result, s-metolachlor was used as the tank mixture partner with sulfentrazone in these trials. Finally, dimethenamid-p was included to compare an alternate graminicide, which offers some control of common ragweed, redroot pigweed, and eastern
Darren E. Robinson, Kristen McNaughton, and Nader Soltani
Ravneet K. Sandhu, Laura E. Reuss, and Nathan S. Boyd
combination with herbicides applied PRE and POST ( Yu et al., 2019 ). Several PRE herbicides, including sulfentrazone, S-metolachlor, and fomesafen, are registered in tomato and are applied on raised beds under the plastic mulch ( Boyd et al., 2019 ; Mohseni
Michael P. Crotser, Leslie A. Weston, and Robert McNiel
Sulfentrazone is a promising new herbicide now under evaluation for use in agronomic and ornamental cropping systems. Sulfentrazone selectively controls yellow nutsedge, morningglories, and other annual grasses and broadleaf weeds. Research was conducted to evaluate the efficacy of sulfentrazone in combination with other labeled products for preemergence weed control in nursery crops. Treatments included sulfentrazone at 0.56 and 1.12 kg a.i./ha and sulfentrazone at 0.37 kg a.i./ha in combination with the following; dithiopyr at 0.37 kg, oxyfluorfen at 0.56 kg, metolachlor at 3.36 kg, isoxaben at 0.56 kg, norfluorazon at 2.64 kg, and isoxaben plus oryzalin at 2.24 kg a.i./ha. Combinations of sulfentrazone with isoxaben or metolachlor provided superior control of morningglory spp., honeyvine milkweed, Carolina horsenettle, and yellow nutsedge. Sulfentrazone plus oxyfluorfen or isoxaben plus oryzalin also provided good control. Poorest overall control was obtained with sulfentrazone plus dithiopyr. Viburnum and deciduous holly were slightly injured 4 WAT with sulfentrazone plus metolachlor. Sulfentrazone plus dithiopyr treatments resulted in serious injury to burning bush 4 WAT and slight injury at 8 WAT.
James T. Brosnan, Gregory R. Armel, William E. Klingeman III, Gregory K. Breeden, Jose J. Vargas, and Philip C. Flanagan
Willis, 2006 ). No tall fescue ( Festuca arundinacea ) injury was observed following either treatment. Sulfentrazone is a protox inhibitor in the same chemical class as carfentrazone-ethyl that can be absorbed by the roots and shoots of treated plants
Kimberly B. Collins, Leslie A. Weston, and Robert E. McNiel
The nursery industry currently has few options for effective season-long weed control, because few soil persistent herbicides are registered for use in ornamentals. An herbicide that provides season-long weed control with minimal injury to ornamentals would be extremely beneficial because it would enable the nurseryman to produce high-quality ornamentals with minimal weed interference Sulfentrazone (F6285), a newly developed herbicide from the FMC Corp., has shown promising results for weed control in field trials with ornamentals. Additional, trials are needed to further evaluate sulfentrazone in hopes that it may be registered for use in ornamentals in the future. Our objectives are 1) to increase long-term weed management in ornamentals, including woody species and groundcover; 2) to evaluate rate structures of sulfentrazone and combinations, including preemergence and postemergence herbicides; 3) to evaluate sulfentrazone selectivity in weed species and in ornamentals; 4) to evaluate sulfentrazone mode of action in weed species; and 5) to measure the soil activity of sulfentrazone. To achieve the first three objectives, a randomized complete block design will be used to evaluate 10 woody species and 17 herbicide combinations. The response variables will be weed control and phytotoxicity ratings taken at 0, 4, 8, and 12 weeks after treatment. The results of this study will be used in ongoing research trials in an attempt to register sulfentrazone (F6285) for use in ornamentals.
Travis W. Gannon, Matthew D. Jeffries, James T. Brosnan, Gregory K. Breeden, Kevin A. Tucker, and Gerald M. Henry
+ sulfentrazone (Echelon; FMC Corporation, Philadelphia, PA). Herbicide application rates and dates are presented in Tables 1 and 2 . All herbicides except oxadiazon used water as the carrier and were applied with CO 2 -powered backpack sprayers at all
Rodrigo Figueroa, Douglas Doohan, and John Cardina
Common groundsel (Senecio vulgaris) is an increasingly important weed in strawberries (Fragaria ×ananassa), a crop in which open space within and between rows is susceptible to infestations. Cultivation, hand hoeing, and registered herbicide are only partially effective in controlling common groundsel, and tolerance or resistance to herbicides is common in this species. Field and greenhouse studies were conducted to identify and select herbicides for controlling common groundsel in newly planted strawberries. Herbicides applied to strawberries within 1 week after planting in 2000 were: terbacil and simazine alone and tank mixed with napropamide; pendimethalin, dimethenamid, metolachlor, ethofumesate and sulfentrazone. Based on selectivity and efficacy observed in this preliminary experiment, sulfentrazone and flumiclorac were selected for further evaluation in 2001 and 2002. Strawberry tolerance of sulfentrazone and flumiclorac 1, 3, 6, and 18 weeks after application (WAA) was similar to that of the registered herbicides terbacil and napropamide, but injury was greater than in hand weeded plots. Plants sprayed with 300 g·ha–1 (4.3 oz/acre) sulfentrazone produced yields similar to terbacil treated plants, but with less plant stunting. Tolerance of newly planted `Allstar' and `Jewel' was affected by the interaction of soil pH and sulfentrazone rate. Plant stunting 3 WAA increased with sulfentrazone rate, reaching 68 and 61% in `Allstar' and `Jewel', respectively, with the highest rate [400 g·ha–1 (5.7 oz/acre)] and high soil pH (7). `Allstar' grown in low pH (5) and treated with sulfentrazone (400 g·ha–1) showed only 8% stunting, whereas `Jewel' was not stunted 3 WAA at the same rate and pH. Both cultivars recovered (50% less stunting) from the severe injury observed when sulfentrazone was applied to high pH soils. However, at low pH both cultivars were stunted more at 6 WAA than at 3 WAA. Plant diameter for both cultivars was 25% higher when they were grown in the lower soil pH. Fruit yield was not affected by the sulfentrazone rates evaluated (0 to 400 g·ha–1). Sulfentrazone was active at four stages of common groundsel growth: preemergence (PRE), cotyledon (COT), early post (EPOST) seedlings at the four-leaf stage, and late post (LPOST) seedlings at the10-leaf stage. The calculated 50% growth reduction (GR50) value for PRE and COT stages was 50 g·ha–1 (0.7 oz/acre), whereas the GR50 for EPOST and LPOST stages was 100 g·ha–1 (1.4 oz/acre). Sulfentrazone controlled common groundsel when applied PRE and COT, but at EPOST and LPOST stages sulfentrazone did not provide complete control, although plant height was reduced 80% to 90% compared to untreated plants. Results indicated that common groundsel is controlled in the field with 150 and 300 g·ha–1 (2.1 and 4.3 oz/acre) of sulfentrazone applied before seedling emergence. The least strawberry injury occurred when sulfentrazone was applied immediately after transplanting at 150 and 300 g·ha–1, although crop tolerance was reduced under conditions of high soil pH (>6.5) and varied with cultivar.
M.J. Haar, S.A. Fennimore, M.E. McGiffen, W.T. Lanini, and C.E. Bell
In an effort to identify new herbicides for vegetables crops, broccoli (Brassica oleracea) cantaloupe (Cucumis melo), carrot (Daucus carota), head lettuce (Lactuca sativa), bulb onion (Allium cepa), spinach (Spinacia oleracea) and processing tomato (Lycopersicon esculentum) were evaluated in the field for tolerance to eight herbicides. The following herbicides and rates, expressed in a.i. lb/acre, were applied preemergence: carfentrazone, 0.05, 0.1, 0.15 and 0.2; flufenacet, 0.525; flumioxazin, 0.063, 0.125 and 0.25; halosulfuron, 0.032 and 0.047; isoxaben, 0.25 and 0.50; rimsulfuron, 0.016 and 0.031; SAN 582, 0.94 and 1.20 and sulfentrazone, 0.15 and 0.25 (1.000 lb/acre = 1.1208 kg·ha-1). Tolerance was evaluated by measuring crop stand, injury and biomass. Several leads for new vegetable herbicides were identified. Lettuce demonstrated tolerance to carfentrazone at 0.05 and 0.10 lb/acre. Cantaloupe and processing tomato were tolerant of halosulfuron at 0.032 and 0.047 lb/acre. Broccoli, cantaloupe and processing tomato were tolerant of SAN 582 at 0.94 lb/acre. Broccoli and carrot were tolerant of sulfentrazone at 0.15 lb/acre.
Grant R. Manning and Steven A. Fennimore
Methyl bromide has been the foundation of chemical weed control in strawberry (Fragaria ×ananassa) in California for over 40 years. The impending phaseout of methyl bromide may leave strawberry producers dependent on less efficacious alternative fumigants for weed control. The use of herbicides to supplement fumigants is a potential weed control strategy for strawberry. A 2-year field study was conducted in California to evaluate 10 herbicides as possible supplements for methyl bromide alternative fumigants. Herbicides were applied immediately after transplanting (immediate posttransplant), and 3 weeks after transplanting (delayed posttransplant). Napropamide applied immediate posttransplant was included as a commercial standard. Immediate posttransplant treatments that were safe in strawberry include carfentrazone at 0.075 and 0.15 lb/acre (0.084 and 0.168 kg·ha-1), flumioxazin at 0.063 lb/acre (0.071 kg·ha-1) and sulfentrazone at 0.175 and 0.25 lb/acre (0.196 and 0.28 kg·ha-1). Triflusulfuron at 0.016 lb/acre (0.017 kg·ha-1) was the only delayed posttransplant treatment with acceptable selectivity. Among the selective herbicides applied immediate posttransplant, flumioxazin and napropamide provided the most consistent control of bur clover (Medicago polymorpha) and shepherd's purse (Capsella bursa-pastoris). Triflusulfuron applied delayed posttransplant did not significantly reduce bur clover densities, but did reduce shepherd's purse densities.
Russell W. Wallace and John C. Hodges
including s -metolachlor + pendimethalin (grower standard) and experimental treatments of dimethenamid-p, flumioxazin, flumetsulam, isoxaflutole, mesotrione, sulfentrazone, and trifloxysulfuron. In 2004, a second trial evaluated PRE-applied s -metolachlor