Container-grown Woody Ornamentals Research Articles

Water Conserving Irrigation Practices, Plant Growth, Seasonal Crop Coefficients, and Nutrition of Container-Grown Woody Ornamentals

Irrigation practices for container nursery crops often result in over-application and can lead to leaching of nutrients and reduced growth. Our objectives were to: (1) compare growth and foliar nutrient content for plants under daily water use (DWU) based irrigation treatments, (2) determine DWU of 14 woody ornamental taxa, and (3) classify taxa into irrigation functional groups based on crop coefficients (KC). Irrigation was applied daily to 8 taxa in 2009 and 2010 using a control of 19 mm and three irrigation treatments: (1) replacing 100% plant DWU (100DWU) each day, (2) alternating 100% DWU with 75% DWU in a 2-day cycle (100-75DWU), and (3) a 3-day cycle replacing 100% DWU the first day and 75% DWU on the second and third days (100-75-75DWU). In 2009, seasonal average DWU ranged between 8.8 and 17.3 mm depending on taxa and treatment. Most DWU-based treatments resulted in less water applied than the control, yet plant growth was not reduced, and for one taxon (Hydrangea paniculata ‘Limelight’) the 100DWU increased plant growth index. Lower foliar P and K concentrations were found for several taxa in control versus DWU treatments. In 2010, DWU for the season ranged between 2.1- and 22.0-mm d−1 depending on taxa and treatment. Growth was lower only for 100-75-75DWU Hydrangea paniculata ‘Limelight’ compared to other treatments and there were no differences in foliar nutrient content.

Host compatibility and fertilization level modulate mycorrhizal establishment and growth of two ornamental shrubs

Purchase online the PDF of Host compatibility and fertilization level modulate mycorrhizallishment and growth of two ornamental shrubs, Battini, F.,Avio, L.,Incrocci, L.,Carmassi, G.,Agnolucci, M. - Pisa University Press - Article

Remediation of metalaxyl, trifluralin, and nitrate from nursery runoff using container-grown woody ornamentals and phytoremediation areas

Two commonly container-produced woody ornamentals, Salix alba L. ‘Britzensis’ and Sambucus nigra L. ‘Aurea’, were grown in aquatic phytoremediation areas (PAs) to evaluate phytoremediation of trifluralin (2004 and 2005), metalaxyl (2006), and NO3−–N (2004–2006) from nursery runoff. The use of container-grown ornamentals for phytoremediation would prevent land area used in production from being converted into wetlands or vegetated filter strips. Twelve nursery beds (NBs) were constructed and graded to allow runoff collection in a small basin at the west end of each production area. Runoff from each NB drained into a PA that contained one of three treatments: (1) 20 plants of S. alba ‘Britzensis’ grown in containers, (2) 20 plants of S. nigra Aurea’ grown in containers, or (3) a PA with no containers and plants serving as a control. Samples of runoff from NBs and water leaving PAs were collected for trifluralin or metalaxyl and NO3−–N analysis. Phytoremediation areas with container-grown plants remediated trifluralin, metalaxyl, and NO3−–N in runoff water to the same extent as PAs without plants. When data from all treatments were pooled and water exiting PAs was compared to runoff from NBs, PAs were effective in remediating runoff. In 2004 and 2005, overall average trifluralin quantity was reduced by 72% (7.32±0.67mg to 2.03±0.29mg) and 94% (from 7.81±0.86mg to 0.51±0.07mg) as runoff moved through PAs. The overall average metalaxyl quantity was reduced by 48% (34.32±7.98mg to 17.69±2.78mg) as runoff moved through PAs. Nitrate–nitrogen quantities leaving PAs were the same or lower compared to NO3−–N captured from NBs depending on sample day, with the greatest reduction of 98% (373–6.00mg) on 14 July 2006. Plants grown in PAs reached marketable size during the experiment. Using PAs with or without container-grown plants as a component of the PA system would reduce environmental contamination from runoff containing metalaxyl, trifluralin, and NO3−–N, and would reduce harmful effects to aquatic organisms from runoff containing trifluralin or NO3−–N.

Container-grown Ornamental Plant Growth and Water Runoff Nutrient Content and Volume Under Four Irrigation Treatments

Container-grown woody ornamentals were irrigated according to a percentage of daily water use (DWU) or a traditional irrigation rate to evaluate plant growth, irrigation volume, runoff, and nutrient loss from each irrigation treatment. Deutzia gracilis Sieb. and Zucc. ‘Duncan’, Kerria japonica (L.) DC. ‘Albiflora’, Thuja plicata D. Don. ‘Atrovirens’, and Viburnum dentatum L. ‘Ralph Senior’ were grown in 10.2-L (# 3) containers under four overhead irrigation treatments: 1) a control irrigation rate of 19 mm per application (control); 2) irrigation scheduled to replace 100% DWU per application (100DWU); 3) irrigation alternating every other application with 100% replacement of DWU and 75% DWU (100–75); and 4) irrigation scheduled on a three-application cycle with one application of 100% DWU followed by two applications replacing 75% DWU (100–75–75). Applications were separated by at least 24 h. Total irrigation applied for the 100DWU, 100–75, and 100–75–75 treatments was 33%, 41%, and 44% less, respectively, than the total water applied by the control treatment of 123 L per container. Plants grown under the three DWU treatments had a final growth index greater than or equal to plants irrigated by the control treatment depending on species. Daily average runoff volumes from production areas irrigated with 100% and 75% DWU were 66% and 79% lower than average control runoff of 11.4 L·m−2·d−1 across all collection days. Quantity of NO3–-N lost daily across all collection days for the 100% DWU and 75% DWU irrigation volumes averaged 38% and 59% less, respectively, than the control. Daily losses of PO43–- P quantities across all collection days under the 100% and 75% DWU volumes were 46% and 74% lower, respectively, compared with the control. Irrigating according to the DWU treatments used in this study reduced irrigation and runoff volumes and NO3–-N and PO43–-P losses compared with a control of 19 mm per application while producing the same size or larger plants.

Water Conservation, Growth, and Water Use Efficiency of Container-grown Woody Ornamentals Irrigated Based on Daily Water Use

Irrigation scheduling based on plant daily water use (DWU) to conserve water without adversely affecting plant growth compared with a traditional irrigation rate was investigated for 25 common container-grown woody ornamentals. Ten different taxa were grown in 2006 and 2007 and five in 2008 in 10.2-L (No. 3) containers. Overhead irrigation was applied in four treatments: 1) a control irrigation rate of 19 mm (1.07 L per container) per application (control); 2) irrigation scheduled to replace 100% DWU per application (100DWU); 3) irrigation alternating every other application with 100% replacement of DWU and 75% DWU (100-75); and 4) irrigation scheduled on a three application cycle replacing 100% DWU followed by two applications of 75% DWU (100-75-75). Irrigation applications were separated by at least 24 h. Daily water use was calculated by measuring the difference in volumetric moisture content 1 h and approximately 24 h after irrigation. The three DWU treatments reduced total irrigation applied 6% to 75% compared with the control depending on treatment and species, except for Buddleja davidii ‘Guinevere’ in which total irrigation applied by the 100DWU, 100-75, and 100-75-75 treatments was 26%, 10%, and 5%, respectively, greater than the amount applied to the control. Final growth index [(plant height + width A + width B)/3] of all DWU treatments was greater than or equal to the control for all taxa. Forsythia ×intermedia ‘New Hampshire Gold’, Hydrangea arborescens ‘Dardom’, Hydrangea paniculata ‘Unique’, and Weigela florida ‘Wilma’ had higher water use efficiencies (estimated as the change in growth index per liter of water applied) at lower irrigation treatment volumes with no differences in growth index or growth index increase, indicating that further irrigation reductions may be possible without affecting growth. PourThru electrical conductivity of H. arborescens ‘Dardom’, Spiraea fritschiana ‘Wilma’, and Viburnum ×burkwoodii ‘Chenaultii’ measured in 2007 did not accumulate to damaging levels. Final plant size of all taxa under DWU treatments was the same or greater than the control and substantially less water was applied under DWU treatments except for B. davidii ‘Guinevere’.

Rice Hulls, Leaf-waste Pellets, and Pine Bark as Herbicide Carriers for Container-grown Woody Ornamentals

An integrated approach to weed control in nursery containers is crucial if herbicide applications during the growing season are to be reduced. This experiment, conducted in 2002 and 2003 in Urbana, Ill., evaluated rice hulls, leaf-waste pellets, and pine bark as herbicide carriers for the preemergence herbicides oryzalin at 2 lb/acre a.i. and diuron at 1 lb/acre a.i. The efficacy of the treatments in controlling annual weeds and the phytotoxic effects of the treatments on the woody plant species were evaluated in separate completely randomized designs. For the efficacy experiment, no ornamental plants were present and containers were each seeded with a mixture of 1:1:1 (by volume) of annual bluegrass (Poa annua), common groundsel (Senecio vulgaris), and shepherd's purse (Capsella bursa-pastoris) immediately after treatment applications. For the phytotoxicity experiment, ‘Goldflame’ spirea (Spiraea japonica), ‘Hetz Midget’ american arborvitae (Thuja occidentalis), and ‘Snowmound’ nippon spirea (Spiraea nipponica) were evaluated. No weed seeds were sown in the phytotoxicity containers. Treatments for both experiments included spray applications of herbicides with water or with one of the organic mulches as a carrier or one of the mulches alone. Evaluations were done 45 and 120 days after treatment (DAT) in both years. The organic carriers with herbicide sprays gave efficacy visual ratings equivalent to water as a carrier for both herbicides. Phytotoxicity was not observed in the spirea species in either year. For ‘Hetz Midget’ american arborvitae in 2002, diuron with water had the highest visual phytotoxicity rating. Diuron phytotoxicity on the ‘Hetz Midget’ american arborvitae was alleviated when diuron was applied with any of the three mulches as a carrier. Pine bark treatments increased plant biomass for ‘Goldflame’ spirea in 2003, 45 DAT. At 120 DAT in 2002, pine bark gave increased plant biomass as compared with no organic mulch treatments for ‘Goldflame’ spirea. The study was conducted to ascertain whether the use of organic mulches as carriers could reduce phytotoxic effects of a herbicide on container-grown woody ornamentals, improve crop plant biomass, and act as a herbicide carrier for container-grown woody ornamentals.

Fertilization of Two Container-grown Woody Ornamentals Based on Their Specific Nitrogen Accumulation Patterns

Nitrogen accumulation patterns were established for Weigela florida (Bunge.) A. DC. `Red Prince' (fast growth rate) and Euonymus alatus (Thunb.) Sieb. `Compactus' (slow growth rate). From these, daily and biweekly N delivery schedules were designed to match N supply with N accumulation patterns of each taxon. Delivery schedules were sliding scales in that total N applied was controlled by independent increases (or decreases) of N concentration and solution volume. Daily and biweekly N delivery schedules were tested against a constant N rate (200 mg·L-1) and Osmocote 18N-2.6P-9.9K (The Scotts Co., Marysville, Ohio). Plants were grown in 3.8-L containers in 7 douglas fir bark: 2 sphagnum peatmoss: 1 silica sand (0.65 mm; by volume) outdoors in full sun on a gravel pad for 142 d. Within each taxon, Weigela and Euonymus grown with sliding-scale N fertilization schedules had similar total dry weights, leaf areas, and total plant N contents to plants grown with a constant N rate (200 mg·L-1) or Osmocote 18N-2.6P-9.9K. Sliding-scale liquid fertilization based on plant N requirements introduced less total N to the production cycle and resulted in higher N uptake efficiency than fertilization with a constant N rate of 200 mg·L-1. In general, liquid N fertilizer treatments resulted in plants with higher shoot to root ratios than plants treated with Osmocote 18N-2.6P-9.9K. Weigela and Euonymus treated with biweekly schedules were similar to plants treated with daily schedules (same total amount of N delivered with each treatment).

Natural Occurrence of Entomopathogens in Pacific Northwest Nursery Soils and Their Virulence to the Black Vine Weevil,Otiorhynchus sulcatus(F.) (Coleoptera: Curculionidae)

Abstract The black vine weevil Otiorhynchus sulcatus (F.) is the primary insect pest of field and container-grown woody ornamentals in the Pacific Northwest (PNW). These studies were conducted to determine the natural occurrence of soil-borne entomopathogens in PNW nursery soils and determine their virulence to black vine weevil. Soil samples were collected July–September of 2002 from field-grown woody ornamental nursery stock in Oregon, Washington, and Idaho. Sample collection in each state took place in the major nursery production areas. A total of 280 samples was collected (Oregon, 170; Washington, 50; Idaho, 60). Entomopathogens were isolated using insect baiting (nematodes and fungi) as well as semiselective media (fungi). Bacillus thuringiensis Berliner was isolated through sodium acetate selection. Soil-borne entomopathogenic fungi occur widely throughout the major nursery production areas in the PNW. The entomopathogenic fungi Metarhizium anisopliae (Metchnikoff) Sorokin, Beauveria bassiana (Bals...

Influence of fertilization application and growing substrate on container-grown woody ornamentals

Five fertilization systems and seven types of growing substrates were tested with two woody plant species with different nutritional demands (Thuja occidentalis, Pyracantha coccinea) grown in two-litre containers. The experiment was repeated in two vegetative seasons. Application of controlled release fertilizer (CRF) was proved the most reliable; it gave good or at least average results in dependence on used growing substrates. Significant differences between application of CRF and other fertilization systems were with Pyracantha plants. System using slow release fertilizer with additional nitrogen fertilizing also showed good results. Systems based only on liquid feeding were less reliable, with some substrates they showed very good results; with others (peat substrate, peat bark substrates with wood components) they were bad. Similar results were achieved with top dressing of granulated fertilizer. Evaluating the substrates good results were obtained by using mixtures of peat with components with higher content of nutrients – peat bark substrates, peat bark substrates with compost and non-peat mixtures of composted bark, wood fibres and compost. Significant differences between these types of substrates and peat one or peat bark substrate with wood components were both with Thuja plants and especially with Pyracantha plants, which have higher demand for nutrients. The experiments showed that peat based substrates amended with alternative components or non-peat substrates can bring better results than the peat ones.

A Comparison of Overhead Irrigation Scheduling and Switch Tensiometers

Proper irrigation management is essential for producing quality container-grown woody ornamentals and reducing off-site runoff. Research has shown that tensiometers can be used as an effective tool to schedule irrigation for woody ornamentals. The objective of this experiment was to compare the effect of cyclic and tensiometric irrigation methods on growth of lantana. Lantana camara `New Gold' liners were established in a 3 pine bark: 1 peat:1 mason sand (by volume) medium. Low-tension switch tensiometers were compared to scheduled overhead [one time a day (1×) at 0600 and cyclic irrigation three times a day (3×) at 0600, 1200, and 1800] for the production of 1-gallon lantana plants. Three low-tension tensiometers (1/block) were set at 7 cb and allowed to irrigate over a 12-hour period. Three separate planting dates occurred and then terminated after ≈7 weeks. Tensiometric irrigation increased root and shoot growth compared to scheduled irrigation for the 24 May 1999 harvest date. Cyclic irrigation produced plants with shoot and total root weights >1× and tensiometer treatments for the September harvest date. Tensiometers sharply reduced irrigation requirements compared to scheduled irrigation volume by at least 50% of the 1× and 3× treatments weekly. Analysis of nutrients in leachate for June indicated increased B and Fe concentrations in the 3× irrigation treatment. Lower concentrations of Ca, Mg, and Na were measured in August. Lantana growth was acceptable for all irrigation treatments and harvest dates.

423 Tensiometer-controlled Irrigation in Large Container-grown Bald Cypress (Taxodium distichum)

Proper irrigation practices are important in the production of container-grown woody ornamentals. When choosing irrigation methods, nurserymen must attempt to maximize production and comply with public policies mandating decreased water usage and runoff. One of these methods schedules irrigation based on plant demand, using tensiometers to measure matric potential of the substrate. While tensiometers have been used successfully with agronomic crops in the field, their effectiveness in irrigation management of large container-grown woody ornamentals has not been extensively tested. The objective of this study was to determine the effect of four irrigation treatments (7 cb tensiometer setting, 14 cb tensiometer setting, 1 time a day application, 4 times a day application) on the production of the ornamental tree Bald Cypress over a 9-month period. Growth differed significantly among treatments. The highest growth index was observed in the 4 times a day and the 7 cb tensiometer treatments, followed by the 1 time a day and 14 cb treatments, respectively. Effluent and leachate (pH, EC, N, P, K) were also measured. Percent effluent volume was highly variable, with maximum volume occurring in June for the 7 cb setting (82%) and in October for the 1 time a day treatment (47%). Higher pH values (7.0 to 8.0) initially occurred in the timed irrigation treatments and higher EC values (2.0–6.0 mmhos) were found in tensiometer treatments; over time, differences among treatments decreased for both variables. Substrate concentrations of N, P and K varied significantly among treatments, while no significant differences were found in the leaf tissue analysis.

Response of Four Container Grown Woody Ornamentals to Immature Composted Media Derived from Waxed Corrugated Cardboard

Four containerized deciduous ornamental shrubs [deutzia (Deutzia gracilis L.), silverleaf dogwood (Cornus alba ‘Elegantissima’), red-osier dogwood (Cornus sericea L.), and ninebark (Physocarpus opulifolius L.)] were grown during each of two separate growing seasons using 12 different immature (nonaged) composts as media (year one, 12 weeks from start of windrowing; year two, 16-weeks) and also two control nursery mixes (100 percent ground pine bark; and 80:15:5 by volume of pine bark:sphagnum peat:top soil). The compost formulations (volume basis) consisted of spent mushroom substrate (50 percent), waxed corrugated cardboard, 0 percent, 25 percent, or 50 percent), and/or pulverized wood wastes (50 percent, 25 percent, and 0 percent). Supplemental N was added to some composts as poultry manure (18 kg·m−3), soybean wastes (24·kg·m−3), or both at the same application rates. Despite the immaturity of the compost media and the presence of high initial contents of soluble salts primarily from the spent mushroom substrate (EC ≤6.4 dS·m−1, 1:1 v/v medium:water extracts), the top dry weight (averaged over two seasons) of each of the four species grown in compost media, regardless of waxed corrugated cardboard (WCC) level, exceeded that obtained in 100 percent pine bark. Compared with the 0 percent WCC compost, plants of all four species grew better in 25 percent and/or 50 percent WCC compost media and growth in these treatments was more (silverleaf dogwood), similar (deutzia and red-osier dogwood), or less than (ninebark) that in the 80:15:5 nursery mix. Rapid leaching of the potentially toxic soluble salts from the containerized compost media within days after planting minimized any adverse effects on the plants. There was no difference in foliar concentrations of N, P, K, Ca, Mg, Fe, Mn, and Zn due to WCC level, or to the N supplements which had little or no effect on growth. The foliar contents of heavy metals (Cu, Ni, Cr, Cd, Co, and Pb) were low and/or below detection limits.

Cutless and Atrimmec for Controlling Growth of Woody Landscape Plants in Containers

Abstract Cutless (flurprimidol) effectively reduced shoot elongation of container-grown woody ornamentals, including abelia, cotoneaster, crape myrtle, Foster holly, Mystery gardenia, Manhattan euonymus, photinia and rhododendron. Optimum Cutless 50W (flurprimidol) spray rates were 500–600 ppm for most species except for Manhattan euonymus (1250 ppm), Mystery gardenia and Natchez crape myrtle (750 ppm). Optimum Cutless 0.33G (flurprimidol) granular rates were 0.6 kg/ha (0.5 lb/A) for Coral Beauty cotoneaster and Foster holly, and 1.7 kg/ha (1.5 lb/A) for Fraser photinia. Atrimmec (dikegulac) was effective in controlling growth of abelia at spray rates of 1480 ppm, Coral Beauty cotoneaster, and Manhattan euonymus at 1600 ppm, Foster holly, and Fraser photinia at 4440 ppm. Neither Off-Shoot-O nor Trim-Cut (mefluidide) had a significant effect on any of the species studied. None of the growth regulators had a significant effect on nandina.

Restricting Overhead Irrigation to Dawn Limits Growth in Container-grown Woody Ornamentals

Elaeagnus pungens Thunb., Ligustrum japonicum Thunb., Photinia ×fraseri `Red Top', and Rhododendron sp. `Fashion' (azalea) growing in 10.4-liter containers were irrigated only at dawn with overhead impact sprinklers or pulse-irrigated three or four times each day with a drip system. Plant water potential was measured diurnally each week for 24 weeks, and growth was measured at the end of the growing season in December. Overhead irrigation resulted in less growth of all species than plants maintained near 100% container moisture with pulse irrigation. With the exception of photinia, more growth was associated with significantly lower daily accumulated water stress. Water stress of overhead-irrigated plants was generally not severe enough to cause stomata1 closure.

The growth response of container-grown woody ornamentals to controlled-release fertilizers

A range of Australian native and exotic woody ornamentals were grown in a potting medium consisting of 50% composted hardwood sawdust, 25% milled, aged pinebark and 25% coarse sand. Plants were fertilized with two resin-coated controlled-release fertilizers (8–9-month formulations of Osmocote (R) 18N:4.8P:8.3K and Nutricote (R) 16N:4.4P:8.3K plus a basal fertilizer of 0.5 kg m −3 isobutyridene-diurea). More than half of the 16 species showed greater shoot growth with Osmocote than with Nutricote. The difference was probably due to the higher nitrogen content of Osmocote and the different nutrient release-rates of the two fertilizers. Some plants with a high rate of growth were not necessarily very responsive to fertilizer and vice-versa. Root growth showed a similar pattern to shoot growth with respect to fertilizer rate and type. Root shoot ( R S ) ratio declined with increasing fertilizer rate and, at the highest shoot weight, the R S ratio for most species was approximately 0.3. All plants tested could be grown to a marketable size in 12–20 weeks using 4–5 kg m −3 of controlled-release fertilizer as the major source of nutrients.

A Comparison of Oxyfluorfen and Oryzalin in Container-grown Woody Ornamentals1

Abstract During 1979 and 1980, oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide) and oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene] were evaluated on 7 species of container-grown woody ornamentals for full-season weed control, phytotoxicity, and final plant size. These 7 species included cultivars of cotoneaster, euonymus, holly, juniper, privet, pyracantha, and rhododendron. Both oryzalin and oxyfluorfen at the 2.2 kg/ha rate provided 75% or better weed control with little to no injury for 2 months. Oxyfluorfen provided a longer period of weed control than oryzalin on some ornamentals. Higher rates of oxyfluorfen (4.5 and 9.0 kg/ha) increased weed control to provide full 4-month efficacy with limited or no injury and satisfactory plant size. Plant size was proportional to the degree of weed control obtained.

Effects of N, K, and Mg on Growth and Leaf Nutrient Composition of Three Container Grown Woody Ornamentals Inoculated with Mycorrhizae1

Abstract High N fertilization reduced percent infection by Glomus spp. (Glomus fasciculatus (Thaxter Gerd. & Trappe and G. mossae (Nich. and Gerd.) & Trappe) endomycorrhizae on inoculated Podocarpus macrophyllus Thunb., Pittosporum tobira Thunb., and Rhododendron simsii Planch. plants. Inoculation with Glomus spp. benefited growth of the 3 woody plant species even at high levels of fertilization (1250 N, 1250 K and 230 Mg kg/ha·yr−1) although leaf nutrients levels showed little difference from noninoculated plants.

Enhanced Zinc Uptake by Container-grown Shrubs with Applications of Nitrogen Zinc Nitrate Solution1

Abstract Nitrogen zinc nitrate solution was applied to 18 species of container-grown woody ornamentals to determine if Zn levels could be increased and related to increased growth and plant quality. In 13 species there was an increase in Zn concentration as compared to untreated plants. Quality was improved in 3 species without a related increase in Zn content. Fe and Mn concentrations were unaffected in most species and no phytotoxicity was observed.

Effect of nitrogen form and rate on appearance and cold acclimation of three container-grown woody ornamentals

Three woody ornamentals were fertilized with 6 nitrogen sources, each applied at 100, 200 and 400 mg/l N. Toxicity was evident from ammoniacal sources, especially at the high rates. Nitrate sources were not injurious, except on viburnum at the highest rate. Doublefile viburnum was severely injured by all ammoniacal sources, while forsythia showed minimal injury and spreading cotoneaster none. Freezing-studies showed that all plants, whether visually affected by the ammoniacal sources or not, showed more freezing-injury than plants grown with nitrate sources. Nitrogen rate did not affect the degree of freeze injury. The impairment of metabolic processes by excess ammonium nutrition predisposed the plants to greater freeze injury.

Evaluation of Bentazon for Yellow Nutsedge Control in Container-grown Nursery Stock1

Abstract Postemergent applications of bentazon (3-isopropyl-1H-2, 1-3-benzothiadiazon-(4) 3H-one 2, 2 dioxide) at 0.84, 1.68, 3.36 and 6.72 kg ai/ha effectively controlled yellow nutsedge (Cyperus esculentus L.) in nursery containers but all rates severely injured container-grown woody ornamentals.