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  • Author or Editor: B. K. Harbaugh x
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Foliar chlorosis or bleaching, interveinal chlorosis, leaf edge and tip necrosis, a poor root system, and stunted growth of Eustoma grandiflorum (Raf) Shinn seedlings were associated with a medium pH of 5.0 or 5.5 but not when the values ranged from 6.4 to 7.5. The range in medium pH resulting in the best growth of seedings and flowering plants was 6.3 to 6.7. Responses to medium pH were similar, regardless of fertilizer solution pH or cultivar. Eustoma seedling and shoot fresh weights for pH 5.0 and 5.5 were only 23% to 66% of corresponding values for plants grown at pH 6.4. Leaf tissue Zn was extremely high (1050 mg·kg-l dry leaf tissue) at a medium pH of 5.0, but other macro- and micronutrients in leaves were not at abnormal levels.

Free access

Pentas (P. lanceolata Benth.) cv. Ruby Glow Red single node cuttings were grown in 15 cm pots in a glasshouse and developing laterals were pinched to one node. Plants were sprayed with chlormequat (CCC) at 0, 500, 1000, 1500, or 2000 ppm on 5, 10, or 15 days after pinching. An ancymidol (0.5 mg ai/15 cm pot) drench treatment was applied at the above 3 dates. Application date had no effect on plant height and ancymidol had minimal effect. All CCC treated plants were shorter than controls but little differences were recorded among CCC conc. Since most stem elongation occurred after the inflorescence was ca. 2 cm diam., a second experiment with similarly grown plants consisted of CCC sprays of 0, 500, 1000, 2000, or 4000 ppm applied 10 days after pinching. Additional CCC applications were made when the inflorescence was 2 cm diam. All treatments yielded plants shorter than controls which were 57 cm. Plants sprayed initially with CCC at 2000 ppm plus CCC at either 500, 1000, or 2000 ppm at the bud stage ranged from 28 to 32 cm tall, an ideal height range for 15 cm pots. CCC at 4000 ppm appeared to reduce stem turgidity and the inflorescence tended to droop at maturity.

Free access

Abstract

An easy method to estimate water requirements for poinsettia (Euphorbia pulcherrima Willd. ex Kl.) production with practical applications to commercial operations was developed to promote water conservation. A water-requirement prediction equation (P ≥ 0.01, R 2 = 0.78) that used pan evaporation along with plant-canopy height and width as input variables was generated. Equation verification was carried out by comparing plant quality of crops irrigated according to the generated water-requirement prediction equation to crops irrigated “on-demand” or with capillary-mat irrigation. Plants irrigated with the prediction equation were smaller than plants grown with capillary mat, but plant quality ratings for ‘Annette Hegg Diva’ and ‘Dark Red Annette Hegg’ were not significantly different. ‘Gutbier V-10 Amy’ plants grown with irrigation on-demand were of higher quality than plants grown using either the capillary mat or the prediction equation. Applied water was significantly lower for plants irrigated with the prediction equation than would normally be applied in a commercial operation using a conservative fixed daily irrigation rate.

Open Access

Abstract

High quality Exacum plants suited for use as flowering house plants were produced in 10-cm pots using a 3 or 5 kg/m3 rate of a 3- to 4-month controlled-release fertilizer (Osmocote 14N-6.1P-11.6K) or an 8- to 9-month release Osmocote (18-2.6-10) with either capillary mat or overhead irrigation. Flowering plants placed in simulated home conditions had more foliar chlorosis at lower Osmocote rates while floral display decreased with higher Osmocote rates.

Open Access

Abstract

Eight herbicides were evaluated for phytotoxicity to field grown ‘Candidium’ caladiums (Caladium × hortulanum Birdsey) in 1983. The 4 most promising or currently used herbicides were evaluated for weed control and phytotoxicity in 1984. During 1984, 4 applications of 2.24 kg/ha alachlor, 2.24 kg/ha simazine, 1.68 kg/ha oryzalin, and 0.56 kg/ha oxyfluorfen, all in combination with 1 postemergence application of 0.28 kg/ha fluazifop-butyl, were applied to caladiums. Alachlor and oxyfluorfen provided poor weed control and reduced plant vigor, tuber weights, and tuber size in 1984. Simazine provided good weed control, but reduced plant vigor and yield. Oryazlin provided excellent weed control without crop injury. Chemical names used: 2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide (alachlor); 6-chloro-N,N’-diethyl-1,3,5-triazine-2,4-diamine (simazine); 4-(dipropylamino)-3,5-dinitrobenzene sulfonamide (oryzalin); 2-chloro-l-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene (oxyfluorfen); butyl-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy] phenoxy] propanoate (fluazifop-butyl).

Open Access

Abstract

One pot study and 2 field experiments were conducted to evaluate the use of ethephon, acifluorfen, endothall, dinoseb, glyphosate, oxyfluorfen, and paraquat as harvesting aids (removal of root and shoot tissue) in caladium (Caladium × hortulanum Birdsey) tuber production. Of these 7 compounds, paraquat and oxyfluorfen showed the most potential with 2 applications at 15-day intervals reducing ‘Canadium’ and ‘Freida Hemple’ caladium root weight as much as 51% and shoot weight up to 90%. No residual effects were observed for these herbicide treatments when tubers were subsequently forced in a greenhouse. Chemical names used: (2-chloroethyl)phosphonic acid (ethephon); [2-chloro-4-(trifluoromethyl)phonoxy]-2-nitrobenzoate (acifluorfen) (7-oxabicyclo[2.2.1]heptane-2,3-dicarboxylic acid (endothall); 2-(l-methylpropyl)-4,6-cinitrophenol (dinoseb); N-(phosphonomethyl)glycine (glyphosate); 2-chloro-l-(3-ethoxy-4-nitrophenoxy)-4-(trifluormethyl)benzene (oxyfluorfen); (1,1-dimethyl-4,4′-bipyridinium ion (paraquat).

Open Access

Abstract

A wide response was found in flower and foliage characteristics in 53 cultivars encompassing 21 genera of flowering potted plants under simulated home conditions. One or more cultivars performing as well or better than Chrysanthemum ‘Puritan’ or a Sinningia mixture were found in Episcia, Exacum, Capsicum, Ceiosia, Achimenes, Begonia, Catharanthus and Tagetes.

Open Access

Abstract

Chrysanthemums (Chrysanthemum morifolium Ramat. cv. Manatee Iceberg) were grown in plots in the open or under polypropylene 25% shade cloth covered structures and were either treated with pesticides or untreated. The number of stems damaged by lepidopterous larvae before harvest was reduced and chemical control efficiency increased by pest exclusion. Shade cloth improved flower quality ratings 41% and 26%, respectively. In a second experiment, plots grown as before were treated either weekly or on demand (when larval densities were >1/1.5 m2) for Lepidoptera control. Significantly fewer stems were damaged in enclosed plots with 2 insecticidal applications than with 11 applications in unenclosed plots. Shading improved flower quality ratings 29% and 22%, respectively, for plots treated weekly or on demand.

Open Access

Abstract

Twenty eight cultivars of Chrysanthemum morifolium Ramat. varied widely in foliar damage by the vegetable leafminer, Liriomyza sativae Blanchard. The total number of leafmines per 5 stems range from 1.3 for ‘Nob Hill’ to 15.5 for ‘Deep Valiant.’ In general, the standardtype cultivars had less leafminer damage than the spray-types. ‘Iceberg,’ a spray-type cultivar commonly grown in Florida, was more damaged than 11 spray and 9 standard cultivars. Foliage of ‘Bright Yellow Tuneful,’ ‘Divinity,’ ‘Pink Marble,’ ‘Nob Hill,’ ‘Albatross,’ ‘Sea Foam,’ and ‘Colonel Comfort’ had less damage in 2 experiments than foliage of ‘Iceberg.’

Open Access