Two experiments were conducted with pansy (Viola ×wittrockiana Gams `Bingo Yello') to determine the relationship between foliar nitrogen (% of dry weight) (FN) and either sap nitrate concentration (SN) in petioles or SPAD readings of foliage. FN was highly correlated to SN throughout both experiments (r = 0.80 to 0.91). FN was poorly correlated to SPAD readings early in both experiments (r = 0.54 to 0.65), but more highly correlated later when visual symptoms of N deficiency were apparent (r = 0.84 to 0.90). SN determined with the Cardy sap nitrate meter was a reliable predictor of FN in pansy, while SPAD readings were only reliable after symptoms of N deficiency were visually evident. FN can be predicted with SN using the following equation: log(SN) = 0.47*FN + 1.6 [r2 = 0.80, n = 132]. Growers and landscape professionals can use SN readings to predict FN levels in pansy, and thus rapidly and accurately diagnose the N status of their crop.

Two experiments were conducted to evaluate the effects of cyclic irrigation on leachate NO3-N concentration, container leachate volume, total effluent volume, and growth of Ilex crenata Thunb. 'Compacta'. In Expt. 1, container leachate volume was reduced 34% when 13 mm of water was applied in three cycles compared to continuous irrigation of 13 mm per unit time. Forty-nine percent less container leachate volume was collected from a continuous application of 8 mm than from that of 13 mm water. In Expt. 2, container leachate volume was reduced 71% when 6 mm was applied in a single application over 30 minutes compared to 13 mm applied continuously for 1 hour. Total effluent was reduced by 14% and 10% in Expts. 1 and 2, respectively, when 13-mm irrigation was applied in three cycles compared to one continuous irrigation. Container leachate NO3-N concentrations from cyclic irrigation were generally less than leachate NO3-N concentrations from continuous irrigation treatments. The percentage of applied N leached as NO3-N ranged from 46% when 13-mm irrigation was applied in three cycles to 63% when 13-mm irrigation was applied in a single cycle. Leachate NO3-N concentration was reduced as irrigation volume was reduced from 13 to 6 mm in Expt. 2. Percentage of applied N leached as NO3-N was 63%, 56%, and 47% when 13-mm irrigation was applied in one, two, and three cycles, respectively, compared to 19%, 16%, and 15% when 6-mm irrigation was applied in one, two, and three cycles, respectively. 'Compacta' holly shoot and root growth were minimally affected by cyclic irrigation or irrigation volume.

Improved water use efficiency exists for plants grown in modified containers to minimize leaching and reduce irrigation frequency which subsequently reduces NO 3 -N leachate. Salvia splendens `Bonfire' and Impatiens wallerana `Pink' (super elfin hybrid) were potted in ProMix BX medium (Premier Brands, Inc., Stamford, CT) into nine container styles with modified drainage holes to determine leachate volume and quantify NO 3 -N leached. Three styles had four drainage holes on the container side with hole diameters of 0.5, 1.0, and 1.9 cm, respectively; three styles had four drainage holes on the container side and one drainage hole in the bottom center with hole diameters of 0.5, 1.0, and 1.9 cm, respectively; and three styles had one drainage hole in the bottom center with hole diameters of 0.5, 1.6, and 1.9 cm, respectively. Plants were hand watered when an individual container's medium reached 80% of container capacity. Leachate volume, irrigation frequency, and leachate NO 3 -N was reduced as drainage size hole decreased in size and number. Plant quality was similar among container modifications.

Overhead pulse irrigation was evaluated as an alternative irrigation practice to reduce container leachate and irrigation runoff. Six irrigation treatments evaluated included 1.25 cm volume applied at 1, 2, and 3 pulses and 0.63 cm volume applied at 1, 2, and 3 pulses with a 1 hr delay between pulses. Irrigation runoff and container leachate were about 50% less in the 0.63 cm treatments compared to the 1.25 cm treatments. There was a 10-14% reduction in irrigation runoff and 29-32% reduction in container leachate when comparisons were made between the 1 pulse and 3 pulse treatments regardless of the irrigation volume applied. Shoot and root growth of Compacta holly were similar among all treatments.

The effects of overhead pulse irrigation versus conventional overhead irrigation on growth of Ageratum houstonianum `Blue Puff' in 2 media, container leachate volumes and leachate NO 3 -N and NH 4 -N levels were evaluated. Container leachate volumes, and NO 3 -N and NH 4 -N levels were higher with pinebark:sand medium. Container leachate volumes tended to be lower with pulse irrigation compared to conventional irrigation. Shoot dry weights of plants grown in pinebark:peat were greater under conventional irrigation compared to pulse irrigation; however, growth indices, flower number, and NO 3 -N and NH 4 -N levels were not affected by irrigation method in either medium.

Potential exists for reduced water use and improved water quality in container nurseries through redesign of the container to minimize leaching. `Celebrate' poinsettias were grown in trade gallon containers with modified drainage hole number and size. Irrigation was applied when an individual container's medium decreased to 80% of container capacity; a gravimetric method was used to determine daily water requirements. Containers with one drainage hole in the center bottom reduced applied water (13%) and leachate volume (90%) compared to standard nursery containers (4 drainage holes in the side and one in the center bottom). Plant quality was similar with these treatments.

Abstract With empty containers, nontarget herbicide loss was 23 percent when the containers were spaced container to container. Spacing the containers on 20 (8 in) and 30 cm (12 in) centers resulted in nontarget losses of 51 and 80 percent loss respectively. Nontarget losses were similar when a dense canopy plant (Rhododendron × ‘Trouper’) and an open canopy plant (Berberis thunbergii ‘Crimson Pygmy’) were spaced container to container or on 20 (8 in) or 30 cm (12 in) spacings.

Water samples containing 0, 2.5, 10.0, or 20.0 ppm nitrate and ammonia were evaluated under 3 temperatures (0, 6, 20C) plus or minus sulfuric acid (36N) for changes in concentration. Ammonia and nitrate levels were measured 0, 1, 2, 4, 8, 16, 24, and 32 weeks after storing. Response to storage conditions was the same regardless of acid or concentration of ammonia or nitrate. Nitrate concentrations in the storage locations were similar for the first 2 weeks. Afterwards, treatments stored at room temperature fluctuated from initial standards. With ammonia, frozen samples had the greatest deviation from initial standards during the first 4 weeks. By week 24, ammonia samples stored at room temperature had exceeded acceptable deviations from the standards. Nitrate and ammonia samples held in refrigeration had the least fluctuation during the 32 week storage period.

The ergosterol-biosynthesis inhibitor (EBI) fungicides myclobutanil, Dusilazole, and tebuconazole were compared with chlorothalonil and triforine for the control of black spot on rose. Myclobutanil at 0.024 or 0.048 g a.i./L and flusilazole at 0.07 or 0.14 g a.i./L, applied weekly, were as effective as chlorothalonil and superior to triforine in controlling black spot. Disease control with myclobutanil and flusilazole at 14-day spray intervals gave poorer control than weekly applications

A 2-year study evaluated the effects of three weed species: eclipta [Eclipta alba (L.) Hasskarl], prostrate spurge (Euphorbia supina Raf.), and wood sorrel (Oxalis stricta L.) on growth of container-grown `Gumpo White Sport' azalea (Rhododendron eriocarpum), R. x `Fashion', and Berberis thunbergii DC. var. atropurpurea `Crimson Pigmy'. Competitiveness among weed species as ranked from greatest to least was eclipta, prostrate spurge, and wood sorrel. Greater populations of eclipta and prostrate spurge resulted in decreased shoot dry weight of `Fashion' and `Gumpo White Sport' azalea. Prostrate spurge had a similar effect on `Crimson Pigmy' barberry in both small (3.8-liter) and large (15.2-liter) containers, while eclipta reduced shoot dry weight of barberry only in large containers. Wood sorrel had little effect on shoot dry weight of `Fashion' and `Gumpo White Sport' azalea.

Abstract Control of large crabgrass [ Digitaria sanguinalis (L.) Scop.] and goosegrass [ Eleusine indica (L.) Gaertn.] was evaluated with the preemergence herbicides oryzalin (Surflan), oxyfluorfen (Goal), and metolachlor (Dual) and the postemergence herbicides quizalofop (Assure), fenoxaprop-ethyl (Whip), haloxyfop (Verdict), poppenate-methyl (Trophy), fluazifop-P (Fusilade 2000), and sethoxydim (Poast) when applied alone or in combination. Oryzalin combinations provided maximum preemergence control compared to oxyfluorfen or metolachlor combinations. Greatest preemergence and post-emergence control was obtained with oryzalin or metolachlor applied with poppenate-methyl. Antagonism of preemergence or postemergence control occurred with several combinations of preemergence and postemergence herbicides. In some instances, control was enhanced by using other herbicide combinations. Chemical names used: 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide (oryzalin); 2-chIoro-1-(3-ethoxy-4-ni-trophenoxy)-4-(trifluoromethyl)benzene (oxyfluorfen); 2-chloro- N -(2-ethyl-6-methyl-phenyl)- N -(2-methoxy-1-methylethyl) acetamide (metolachlor); ½(±)-2-[4-[(6-chloro-2-quinoxyalinyl)oxy]phenoxy]propanoic acid¼ (quizalofop); (±)-ethyl 2-[4-[(6-chIoro-2-benzoxazolyl) oxy] phenoxy] propanoate (fenoxaprop-ethyl); 2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid (haloxyfop); methyl 3-hydroxy-4-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]-pentanoate (poppenate-methyl); ( R )-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid (fluazifop-P); and 2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio) propyl]-3-hydroxy-2-cyclohexen-1-one (sethoxydim).

Abstract Selected herbicides were evaluated for weed control in a two-year field test with boxwood, holly, viburnum and nandina. Gallery (isoxaben), when applied alone, generally provided inferior grass control during year one compared to Surflan (oryzalin). Surflan in combination with Gallery at 3.4 + 1.1 kg/ha (3.0 + 1.0 lb/A) provided weed control similar to that obtained with traditional herbicide programs of Surflan in combination with Princep (simazine) and/or Goal (oxyfluorfen). Plant size of four woody plant species, treated twice annually with Surflan + Gallery over a two year period, was statistically equivalent to the maximum plant size obtained with any other treatment.

Abstract Preemergence herbicides were evaluated for control of yerba-de-tago [ Eclipta alba (L.) Hasskarl] and for phytotoxicity to four container-grown landscape species. Herbicides providing excellent control (less than one weed/pot) were chlorimuron at 0.035 and 0.07 kg·ha -1 , chlorimuron + metribuzin at 0.075 + 0.485 kg·ha -1 , and oryzalin at 4.5 and 9.0 kg·ha -1 . Injury within 30 days after treatment occurred with applications of oxyfluorfen, lactofen, and fomesafen at the × 1 and × 2 rates on Ilex vomitoria Ait. ‘Nana’ (dwarf yaupon), Rhododendron satsuki ‘Pink Gumpo’ (‘Pink Gumpo’ azalea), R. obtusum (Lindl.) Planch. ‘Coral Bells’ (‘Coral Bells’ azalea), and Liriope muscari L. ‘Big Blue’ (lily turf). Injury symptoms were not present after 60 days, except with applications of lactofen at 0.44 kg·ha -1 and fomesafen at 1.1 kg·ha -1 . All other herbicides were safe on the four ornamental species. Chemical names used: 2-chloro- N -(2-ethyl-6-methylphenyl)- N -(2-methoxy-1-methylethyl)acetamide (metolachlor); N , N -diethyl-2-(l-naphthaIenyloxy)propanamide (napropamide); 3-[2,4-dich-loro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3 H) -one (oxadiazon); 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene (oxyfluorfen); N -(l-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin); 6-chloro- N,N- diethyl-1,3,5-triazine-2,4-diamine (simazine); 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide (oryzalin); methyl 5-(2,4-dichlorophenoxy)-2-nitrobenzoate (bifenox); 2-chloro- N -(2,6-diethylphenyl)- N -(methoxymethyl)acetamide (alachlor); 2-[[[[4-chloro-6-methoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]benzoic acid (chlorimuron); 4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4 H )-one (metribuzin); (±)-2-ethoxy-l-methyl-2-oxoethyl 5-[2-chloro-4-(trifluoromethyl)phenoxyl]-2-nitrobenzoate (lactofen); and 5-[2-chloro-4-(trifluoromethyl)phenoxyl]- N -(methysulfonyl)-2-nitrobenzamide (fomesafen).

Daconil 2787, Spotless, Systhane, Maag RO15-1279, and Funginex were evaluated for blackspot control on field-grown roses. Weekly applications of Systhane at 0.16–0.20 g ai/l (0.021–0.027) oz ai/gal) and Maag RO15-1279 at 0.10 g ai/l (0.013 oz ai/gal) provided season-long blackspot protection equal to Daconil 2787. Lower rates of both Maag RO15-1279 and Systhane were less effective than the recommended rates of both fungicides. Spotless retarded shoot elongation while Systhane and Maag RO15-1279 did not.

Selected herbicides were evaluated for control of southern yellow wood sorrel ( Oxalis dillenii Jacq.) in three experiments. Control varied depending on rate of application and the time interval after application. Herbicides providing excellent control (less than one weed/pot) 8 weeks after treatment with the 0.5 × rate included: oxyfluorfen, 1.1 kg·ha –1 ; oryzalin, 2.2 kg·ha –1 ; and oxyfluorfen + oryzalin, 1.7 kg·ha –1 . Control 18 weeks after treatment was excellent at the 1× rate with oryzalin (4.5 kg·ha –1 ) and at the 2× rates with oryzalin (9.0 kg·ha –1 ), oxyfluorfen (4.5 kg·ha –1 ), and a combination of the two. Chemical names used: 2-chloro-l-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene (oxyfluorfen); 4-(dipropylamino)-3,5-dinitrobenzenesulfonamide (oryzalin).

Flurprimidol effectively suppressed growth of Acer rubrum when applied as a subsoil injection. Rates of 1.0 and 2.0 g ai/inch of diameter supressed height growth for about three years; whereas, 0.5 g ai/inch of diameter suppressed growth less than the higher rates, and effectiveness subsided during the second year. Diameter growth suppression increased with flurprimidol rates, though suppression was not as pronounced as with height growth. Tree height, diameter, and shoot length were suppressed with all rates of flurprimidol compared to nontreated trees. Tree appearance was affected by flurprimidol. Reduced petiole length and smaller, dark-green leaves were evident with treated maples compared to nontreated plants, though appearance was not objectionable.