Search Results
Abstract
Plants of the ‘Cara Mia’ rose (Rosa hybrida L.) grown at elevated day temperatures with long photoperiodic cycles or at reduced night temperature with short photoperiods differed in shoot growth rate, petal number, final stem length, and harvest date when compared to plants grown at suggested day and night temperatures. Node number remained nearly constant under all growing conditions. Plants of ‘Town Crier’ rose grown with a night temperature of 13°C (minimum) during the first 3 weeks following shoot removal produced flowering shoots of the same length in the same amount of time as did those grown at a minimum night temperature of 17°C throughout shoot development. Cooler night temperatures during the second 3-week period after shoot removal increased flower development time by four days but did not affect stem length. Results indicate that some rose cultivars can tolerate lower than normal night temperatures for a portion of the growing cycle without reduced growth and/or yield.
Abstract
The longevity and quality of flowers experimentally shipped from California to Maryland by refrigerated trucks for 4–5 days were comparable with or better than simulated air-shipped flowers when properly handled. Flowers shipped by air are usually not refrigerated in transit. Best results with ‘White Sim’ carnations (Dianthus caryophyllus L.), ‘Albatross’ standard chrysanthemums (Chrysanthemum morifolium Ramat) and ‘Cara Mia’ roses (Rosa hybrida L.) were obtained when flowers were pretreated after harvest with a chemical solution for 16 hours, precooled prior to shipment and shipped in insulated boxes. Preshipment pulsing of carnations and chrysanthemums increased longevity and bloom diameter. Pulsing of ‘Cara Mia’ roses extended longevity and prevented “bent neck.” Chrysanthemums and roses benefited from ice in the box even with good refrigeration but carnations did not. Carnations and chrysanthemums cut at a tight bud stage suffered much less than open blooms from heat stress conditions during handling of flowers.
Abstract
Excessive temperatures recorded within flower boxes on transcontinental refrigerated trucks were avoided by using an integrated system of preshipment cooling with forced-air, standardized containers and appropriate stacking pattern. The longevity and quality of flowers shipped from California to Florida by refrigerated trucks were comparable to or better than that of air-shipped flowers. Preshipment conditioning treatments did not improve flower longevity of shipped roses, carnations or gladioli. Preconditioning chrysanthemum stems in AgNo3 solution eliminated the need to recut stems after shipment. Carnations and gladioli handled dry lasted as long as conditioned flowers. Floral preservative used on roses and carnations after shipping had a more positive affect on longevity than any other handling treatment.
The eriophyid mite, Phyllocoptes fructiphilus, vectors the causal agent, Rose rosette virus (RRV), that results in rose rosette disease. Parts of the southeastern United States have remained free of the disease, except for infected plant material introductions that were eradicated. A survey of sampling points through Alabama, Georgia, and Mississippi (n = 204) revealed the southeastern border of RRV. The presence of RRV in symptomatic plant tissue samples (n = 39) was confirmed by TaqMan-quantitative reverse transcription polymerase chain reaction (RT-qPCR). Samples were also collected at every plot for detection of eriophyid mites, specifically for P. fructiphilus. Three different species of eriophyid mites were found to be generally distributed throughout Alabama, Georgia, and Mississippi. Most of these sites (n = 60) contained P. fructiphilus, found further south than previously thought, but in low populations (<10 mites/gram of tissue) south of the RRV line of incidence. Latitude was found to be significantly correlated with the probability of detecting RRV-positive plants, but plant hardiness zones were not. Plot factors such as plant size, wind barriers, and sun exposure were found to have no effect on P. fructiphilus or the presence of RRV. The reason for the absence of RRV and low populations of P. fructiphilus in this southeast region of the United States are unclear.