Effect of High Temperatures on the Postharvest Flowering of Specialty Floral Crop Species

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447f-448
Author(s):  
Millie S. Williams ◽  
Terri Woods Starman ◽  
James E. Faust
Keyword(s):  
United States ◽  
Heat Tolerance ◽  
Flower Development ◽  
Consumer Satisfaction ◽  
The United States ◽  
Plant Canopy ◽  
Flower Number ◽  
Flower Bud ◽  
Crop Species ◽  
Mature Flower

Flower growers experience decreased consumer satisfaction with plant species that cease flowering during the summer. The objective of this experiment was to characterize the heat tolerance of four specialty floral crop species in order to predict their summer performance in the different climatalogical regions of the United States. The effect of increasing temperatures on the duration of postharvest flower development was determined for Ageranthemum frutescens `Butterfly' and `Sugar Baby', Brachycome hybrid `Ultra', and Sutera cordata `Snowflake'. Plants were grown in a 18 °C greenhouse until marketable with foliage covering the container and flowers distributed evenly across the plant canopy. Plants were then placed in a phytotron to determine their heat tolerance. Temperature set points of 18, 23, 28, and 33 °C were delivered serially at 2-week intervals, starting at 18 °C. Plants were then returned to 18 °C after the 33 °C treatment. Immature flower bud, mature flower bud, flower and senesced flower numbers were collected once per week. Sutera `Snowflake', and Brachycome `Ultra' had the greatest flower number at the 23 °C temperature, decreasing in the 28 °C environment. Argeranthemum `Butterfly' and `Sugar Baby' had greatest flower number at 28 °C, but flowers were smaller and of lower quality than at 23 °C. Flower development of all cultivars ceased at 33 °C, but when plants were returned to the 18 °C production greenhouse, flower development resumed. According to normal average daily temperatures in Knoxville, Tenn., Ageranthemum frutescens `Butterfly' and `Sugar Baby' would flower until mid-June, while Brachycome hybrid `Ultra' and Sutera cordata `Snowflake' would flower until mid-May.

scholarly journals High Temperatures Reduce Postharvest Flowering of Specialty Floral Crop Species

1999 ◽  
Vol 9 (1) ◽  
pp. 94-98
Author(s):  
Millie S. Williams ◽  
Terri W. Starman ◽  
James E. Faust
Keyword(s):  
High Temperatures ◽  
Heat Tolerance ◽  
Flower Development ◽  
Flower Number ◽  
Flower Bud ◽  
Crop Species ◽  
Specialty Crop ◽  
Swan River ◽  
Warm Climates

The effect of increasing temperatures on the duration of postharvest flower development was determined for three specialty crop species: marguerite (Argyranthemum frutescens Webb ex Schultz-Bip.) `Butterfly' and `Sugar Baby'; swan river daisy (Brachycome hybrid Cass.) `Ultra'; and bacopa (Sutera cordata Roth.) `Snowflake'. Plants were grown in a greenhouse at 18 °C (65 °F) until flowering, and then transferred into a phytotron to determine heat tolerance. Plants were stored for 8 weeks at constant temperatures of 18, 23, 28, and 33 °C (65, 73, 82, and 91 °F) for 2-week intervals. Flower bud and flower number were recorded weekly. Sutera cordata `Snowflake' and B. hybrid `Ultra' had the greatest flower number at the 23 °C temperature, decreasing in the 28 °C environment. Argyranthemum frutescens `Butterfly' and `Sugar Baby' had greatest flower number at 28 °C, but flowers were of lower quality thanat 23 °C. Flower development of all cultivars ceased at 33 °C, at the end of 8 weeks at increasing temperatures, but when plants were returned to the 18 °C production greenhouse, flower development resumed. High temperatures (28 °C) reduce the postharvest performance of S. cordata, B. hybrid, and A. frutescens plants grown in hanging baskets; therefore, these species should be marketed as spring-flowering products since summer performance may be unsatisfactory in warm climates.

scholarly journals Performance of Landscape Roses Grown with Minimal Input in the North-central, Central, and South-central United States

2017 ◽  
Vol 27 (5) ◽  
pp. 718-730 ◽  
Author(s):  
David C. Zlesak ◽  
Randy Nelson ◽  
Derald Harp ◽  
Barbara Villarreal ◽  
Nick Howell ◽  
...  
Keyword(s):  
United States ◽  
National Level ◽  
The United States ◽  
The South ◽  
Flower Number ◽  
North Central ◽  
The North ◽  
South Central ◽  
Central United States ◽  
Plant Hardiness

Landscape roses (Rosa sp.) are popular flowering shrubs. Consumers are less willing or able to maintain landscape beds than in years past and require plants that are not only attractive, but well-adapted to regional climatic conditions, soil types, and disease and pest pressures. Marketing and distribution of rose cultivars occurs on a national level; therefore, it is difficult for U.S. consumers in the U.S. Department of Agriculture (USDA) Plant Hardiness Zones 3 to 5 to identify well-adapted, cold-hardy cultivars. Identifying suitable cultivars that have strong genetic resistance to pests and disease and that will tolerate temperature extremes without winter protection in the USDA Plant Hardiness Zones 3 to 5 is of tremendous value to consumers and retailers in northern states. Twenty landscape rose cultivars, primarily developed in north-central North America, were evaluated at five locations in the United States (three in the north-central United States, one in the central United States, and one in the south-central United States) using the low-input, multiyear Earth-Kind® methodology. Six roses had ≥75% plant survival at the end of the study and were in the top 50% of performers for overall mean horticultural rating at each of the three north-central U.S. sites: ‘Lena’, ‘Frontenac’, ‘Ole’, ‘Polar Joy’, ‘Sunrise Sunset’, and ‘Sven’. Five of these six roses met the same criteria at the central United States (exception ‘Lena’) and the south-central United States (exception ‘Polar Joy’) sites. Cultivar, rating time, and their interaction were highly significant, and block effects were not significant for horticultural rating for all single-site analyses of variance. Significant positive correlations were found between sites for flower number, flower diameter, and overall horticultural rating. Significant negative correlations were found between flower number and diameter within each site and also between black spot (Diplocarpon rosae) lesion size from a previous study and overall horticultural rating for three of the five sites. Cane survival ratings were not significantly correlated with overall horticultural rating, suggesting some cultivars can experience severe winter cane dieback, yet recover and perform well. Data from this study benefit multiple stakeholders, including nurseries, landscapers, and consumers, with evidence-based regional cultivar recommendations and breeders desiring to identify regionally adapted parents.

scholarly journals Introduction of the New World Squash leaf curl virus to Squash (Cucurbita pepo) in Egypt: A Potential Threat to Important Food Crops

Plant Disease ◽  
2006 ◽  
Vol 90 (9) ◽  
pp. 1262-1262 ◽  
Author(s):  
A. M. Idris ◽  
A. Abdel-Salam ◽  
J. K. Brown
Keyword(s):  
United States ◽  
New World ◽  
The United States ◽  
Pcr Analysis ◽  
Broad Host Range ◽  
Species Introduction ◽  
Crop Species ◽  
Squash Leaf Curl Virus ◽  
Leaf Curl Virus ◽  
Leaf Curl

Squash plants showing leaf curling, yellow mottling, and reduced fruit set were observed in fields in Giza, Egypt in spring 2005. These particular symptoms had not been observed previously in zucchini squash plants in Egypt, but were reminiscent of those caused by begomoviruses (Geminiviridae) that are known to occur in the region, including Watermelon chlorotic stunt virus. Squash plants were heavily infested with the whitefly Bemisia tabaci (Genn.), the only known vector of begomoviruses. Total nucleic acids were isolated from symptomatic squash leaves using the cetyltrimethylammoniumbromide method, and extracts were subjected to polymerase chain reaction (PCR) analysis using two sets of PCR primers. One primer set (prAV2644 and prAC1154) was designed to amplify a fragment that contains the entire viral coat protein (Cp), while the second primer set (prBV1855 and prBC656) was designed to amplify the common region (CR) of DNA-B of begomoviruses (1). The expected size fragments were cloned and the sequence was determined for five clones each. Unexpectedly, the Cp and the CR-B fragments shared their highest nucleotide sequence (nt) identity among well-characterized begomoviruses to the bipartite Squash leaf curl virus (SLCV) native to the western United States. A third primer set (prAC344 and prAV1134) (1) was subsequently used to amplify the remainder of the putative SLCV DNA-A. The fragment was cloned and the DNA sequence was determined. Assembly of the overlapping DNA-A fragments resulted in a complete DNA-A component sequence of 2,636 nt, which is identical to the expected size of the SLCV DNA-A component (GenBank Accession No. DQ285019). Comparison with the latter sequence indicated that the Egyptian squash isolate shared 98% nt identity with SLCV. The sequence for the DNA-B fragment (1,162 nt) shared 94% nt identity with SLCV and was deposited in GenBank as Accession No. DQ285020. The high-shared nt identity with SLCV (2) from the United States suggests that this isolate, herein SLCV-EG, has been introduced into Egypt. The relatively low DNA-B nt sequence identity was a not a surprise since this component is normally less conserved even between strains of a single begomoviral species. Introduction of SLCV is not only potentially significant to the domestic production of crop species in the Cucurbitaceae but also for legume crops. SLCV has a broad host range that also includes members of the Fabaceae, which includes species that contribute significant sources of protein for much of Egypt's population. The virus thus far is thought to be present only in Lower Egypt, however, it could feasibly threaten legume and cucurbit crops if it spreads to Upper Egypt. To our knowledge, this is the first begomovirus of New World origin to become established in the Old World. References: (1) A. M. Idris and J. K. Brown. Phytopathology 88:648, 1998. (2) S. G. Lazarowitz. Virology 180:70, 1991.

scholarly journals Performance of 15 Exacum affine Genotypes in a Low-irradiance Environment

HortScience ◽  
1991 ◽  
Vol 26 (9) ◽  
pp. 1215-1216 ◽  
Author(s):  
David B. Rubino
Keyword(s):  
Photosynthetically Active Radiation ◽  
Flower Development ◽  
Flower Color ◽  
Plant Canopy ◽  
Leaf Color ◽  
Flower Bud ◽  
Active Radiation ◽  
Color Development ◽  
Exacum Affine

Fifteen cultivated genotypes of Exacum affine Balf. were evaluated for flower development and for flower and leaf color at 0 days (marketable stage, ≈ 25% of plant canopy covered with flowers), and after 14 and 28 days of maintenance in a low-irradiance environment (≈ 1 μmol·m-2·s-1 photosynthetically active radiation from cool-white fluorescent lights for 12 hours daily). Flowering and flower color development were reduced, but leaf color improved during maintenance under low irradiance. Variability was observed among the 15 genotypes for flower bud and flower color development in a low-irradiance environment.

scholarly journals Effects of Heat Stress on Floral and Vegetative Development in New Guinea Impatiens

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 570f-571
Author(s):  
Kerry M. Strope ◽  
Mark S. Strefeler
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Selection Index ◽  
New Guinea ◽  
Dry Weight ◽  
Flower Number ◽  
Flower Bud ◽  
Combining Abilities ◽  
Heat Tolerant ◽  
New Guinea Impatiens

Fifty-three commercial New Guinea Impatiens cultivars (Impatiens hawkeri Bull.) from six different breeding series were tested for level of heat tolerance. Five floral (flower number, flower length, flower width, floral dry weight, and flower bud number) and five vegetative characteristics (leaf dry weight, stem dry weight, total dry weight, number of nodes, and number of branches) were evaluated with emphasis placed on continued flowering under long term heat stress. Significant differences among cultivars were found in each data category (P ≤ .0001). Flower number varied from 0 to 6, flower length varied from 10 to 51 mm, flower width varied from 10 to 47 mm, floral dry weight varied from 0 to 0.5 g, and flower bud number varied from 0 to 14. Four heat tolerant (Celebration Cherry Red, Celebration Rose, Lasting Impressions Shadow, and Paradise Moorea) and three nonheattolerant (Lasting Impressions Twilight, Danziger Blues, and Pure Beauty Prepona) cultivars were identified using a Weighted Base Selection Index. These cultivars were used as parents in a full diallel crossing block with reciprocals and selfs. One hundred seedlings from each of 49 crosses were evaluated for heat tolerance. General and specific combining abilities of the parents were evaluated as was heritability. It was found that the four heat tolerant cultivars had higher general combining abilities. Heat tolerance has low heritability and is controlled by many genes. Superior genotypes were identified (selection intensity of 0.05) and retained for further evaluation and breeding efforts.

Broomrapes (Orobanchespp.): A Potential Threat to U.S. Broadleaf Crops

1989 ◽  
Vol 3 (4) ◽  
pp. 608-614 ◽  
Author(s):  
Rakesh Jain ◽  
Chester L. Foy
Keyword(s):  
United States ◽  
Host Range ◽  
The United States ◽  
Potential Threat ◽  
Crop Species ◽  
First Report ◽  
Soybean Plants ◽  
First Time

Five broadleaf crops, alfalfa, peanut, soybean, tobacco, and tomato, were tested for their susceptibility to three broomrape species, branched, Egyptian and crenate, in the greenhouse. All five crop species were parasitized by one or more broomrape species. Peanut plants were most susceptible and soybean plants were least susceptible to parasitism by broomrape. Egyptian and branched broomrapes had a wider host range affecting plants in both the Solanaceae and Fabaceae. Crenate broomrape mainly infected plants belonging to Fabaceae, except for the few attachments to tomato and tobacco. Apparently, this is the first report on parasitism of peanut plants by branched broomrape and that of peanut and alfalfa plants by crenate broomrape. Parasitism of soybean plants by any of the broomrape species also was observed for the first time in these experiments. These results indicate that broomrapes, although not a major problem on any of the crops in the United States, could parasitize several major broadleaf crops should the parasite become established.

Two faces of patient safety and care quality: a Franco-American comparison

2011 ◽  
Vol 6 (3) ◽  
pp. 287-294 ◽  
Author(s):  
Laurent Degos ◽  
Victor G. Rodwin
Keyword(s):  
United States ◽  
Primary Care ◽  
Patient Safety ◽  
Consumer Satisfaction ◽  
Health Care Services ◽  
The United States ◽  
Medical Intervention ◽  
Care Quality ◽  
Care Hospital ◽  
Primary Care Hospital

AbstractPatient safety, and more broadly the quality of care, is typically discussed with reference to the reduction of preventable adverse events within hospitals and adherence to practice guidelines on care processes. We call it the ‘care-centered approach’ and recognize that the United States is a leader in the field. Another face of patient safety and care quality may be defined as the ‘system-centered approach’. It focuses on access to a timely and effective continuum of health-care services – clinical prevention, primary care and appropriate referral to and receipt of specialty care. Although France's efforts to pursue a care-centered approach to patient safety are limited, its system-centered approach yields some benefits. Based on the evidence we have reviewed for access to primary care (hospital discharges for avoidable hospital conditions), mortality amenable to medical intervention and consumer satisfaction, in the United States and France, there appear to be good grounds for bolstering the system-centered approach in the United States.

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