Search Results

You are looking at 1 - 10 of 26 items for :

  • "Rhododendron obtusum" x
Clear All

Abstract

‘Autumn Sun’, ‘Cochran's Lavender’, ‘Pink Camellia’, and ‘Wolfpack Red’ azaleas [Rhododendron obtusum (Lindl.) Planch.] were released in 1981 by the North Carolina Agricultural Research Service. Stock plants were made available to commercial nurserymen for the purposes of propagation and distribution in the nursery industry.

Open access cc by nc nd
Authors: and

Abstract

The avg wt increase of subirrigated dormant azalea tops after 75 days was 4.5g and of wax myrtle was 10.0g. The wax myrtle in a 30 cm deep perlite and peat medium produced the greatest fresh and dry wt which was twice as heavy as plants grown in a sand and bark medium. The peat, sand and soil and the peat and sand media produced the greatest new shoot number in azalea. The wax myrtle had greater shoot length in peat, sand and soil, and the per lite and peat media at 30cm depth, than in the peat and sand or the sand and coarse bark media. The azalea produced 5 shoots per plant which averaged 23cm in length, while wax myrtle produced 4 shoots with 41 cm in length. There was a decrease in soluble salt level and media pH but an increase in % media moisture with greater sampling depth from surface to bottom. Subirrigation may be beneficial for a wide variety of plants and cultural conditions since it provided a precise amount of water at all times.

Open access cc by nc nd

Abstract

Rhododendron obtusum (Lindl.) Planch. ‘Hinodegiri’ responded to the different fertilizer sources and application methods similarly regardless of growing media. Plants top-dressed with Osmocote 18N-3P-10K had a significantly higher growth index, larger stem caliper and increased fresh weight than plants top-dressed with Pro-Grow 24N-3P-10K. Incorporation of either fertilizer source resulted in reduced plant growth and quality. The best fertilization method was a surface application regardless of fertilizer source or media.

Open access cc by nc nd

Abstract

Extensive losses in N applied to container-grown woody ornamental plants prompted this investigation to determine a) leaching of N from urea (U) and isobutylidene diurea (IBDU); b) influence of nitrapyrin (NI), a nitrification inhibitor, on N leaching losses from U; and c) to evaluate influences of these materials on growth, quality, and N uptake by Rhododendron obtusum Lindl. cv. Hinodegiri. In root medium composed of 60 pine bark : 30 sand : 10 soil (by volume), 48.8% of applied N from U was leached after 87 days, whereas leachate losses of N from IBDU and U + NI were 42.3% and 37.2%, respectively. All plants attained marketable quality by the end of the study. Azaleas fertilized with IBDU were of significantly higher quality on days 70 and 77 than those treated with U + NI and higher quality on days 77, 84, and 87 than those treated with U. No differences were found in shoot dry weight or N content in shoot tissues.

Open access cc by nc nd

Abstract

Rooted cuttings of Ilex crenata Thunb. ‘Helleri’, Rhododendron obtusum Planch. ‘Rosebud’, and Juniperus chinensis L. ‘San Jose’ were grown in a 100% pine-bark medium amended with dolomitic limestone at 0 to 8 kg m-3 with resulting pH from 3.4 to 7.2. Except for juniper at 2 kg m-3, growth was not increased by liming, and 8 kg m-3 tended to reduce shoot and root growth. This reduced growth was attributed in part to greater NH4 adsorption by the bark, reducing the amount available for plant uptake, and a higher nitrification rate, leading to an elevated NO3 to NH4 ratio in the medium. Liming pine bark to improve growth of these woody plants may be unnecessary.

Open access cc by nc nd

Abstract

Foliar spray applications to ‘Gloria’ azalea (Rhododendron obtusum) of daminozide, chlormequat chloride, daminozide/chlormequat chloride combination, ancymidol, paclobutrazol, fluometralin, NAA, and IBA were applied prior to bypass shoot development. All treatments except IBA reduced bypass shoot length. NAA treatments were phytotoxic, and fluometralin inhibited flowering. Rate of flower development was retarded by daminozide, chlormequat chloride, and daminozide/chlormequat chloride combination, but was unaffected by ancymidol, paclobutrazol, fluometralin, NAA, and IBA. Paclobutrazol was the most efficient and effective treatment in reducing bypass shoot length without affecting flower size or time to flower. Chemical names used: butanedioic acid mono (2,2-dimethylhydrazide) (daminozide); 2-chloro-N,N,N-trimethyl-ethanaminium chloride (chlormequat chloride): α-cyclopropyl-α-(4-methoxyphenyI)-5-pyrimidinemethanol (ancymidol): β,[(4-chlorophenyl)methyl)-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol): 2-chloro-N-[2,6-dinitro-4-trifluoromethyl)phenyl]-N-ethyl-6-fluorobenzenemethanamine (fluometralin): 1-naphthaleneacetic acid (NAA): 1H-indole-3-butyric acid (IBA).

Open access cc by nc nd

. ‘Chesapeake’), azalea ( Rhododendron obtusum Planck. ‘Karen’), and marigold ( Tagetes erecta Big. ‘Inca Gold’) could be grown in a noncomposted PTS (100% wood) produced from debarked loblolly pine trees. Nutrient analysis of the PTS substrate solution

Free access

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-(3H)-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(4H)-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).

Open access cc by nc nd
Authors: and

Wheat bran inoculum of Penicillium janthinellum (Biourge) [1% w/w added to pine bark (PB) container medium] suppressed “`root rot of azalea (Rhododendron obtusum Planch.) caused by Phytophthora cinnamomi Rands in greenhouse experiments. Shoot fresh weight was increased by 31% to 91% and mortality reduced by 30% to 50% for azaleas planted in natural (nonsterile) PB amended with P. janthinellum compared with the infested control. The population densities of P. janthinellum exceeded 105 to 106 cfu/g dry PB within 7 days and remained stable over time. Penicillium janthinellum, a natural colonizer of PB container media, shows potential as a biological control of phytophthora root rot of azalea.

Free access
Authors: and

Abstract

Coal cinders with pine bark were evaluated as containerized plant growing medium. Rhododendron obtusum Lindl. ‘Hinodegiri’ liners were grown in several combinations of media composed of pine bark mixed with an aged and a recently combusted source of cinders. Measurements of media pH, soluble salts, NO3 –N, NH4 + –N, and 19 extractable nutrient and metallic ions were obtained. Leaf tissue samples were analyzed for 19 elements. Top dry weight, visual growth and chlorosis ratings, and root visual ratings constituted the plant growth parameters measured. Satisfactory growth was generated in pine bark amended with up to 50% cinders from either source.

Open access cc by nc nd