relationship between external bud appearance and the presence/absence of flower initials has not been systematically evaluated, particularly among recent cultivar releases ( Lenhardt and Eaton, 1977 ; Patten and Wang, 1994 ). External bud appearance is an
Lisa Wasko DeVetter, Rebecca Harbut, and Jed Colquhoun
Renee T. Threlfall, John R. Clark, Aubrey N. Dunteman, and Margaret L. Worthington
-round availability. The development of new blackberry cultivars with improved appearance, flavor, thornlessness, season extension, and postharvest performance will enhance consumer perceptions of the crop and support further industry expansion. Despite recent growth
Esnath T. Hamadziripi, Karen I. Theron, Magdalena Muller, and Willem J. Steyn
ambient temperature. Apple fruit appearance and eating quality can vary considerably between trees in an orchard and within the tree ( Johnson and Ridout, 2000 ), and this may relate to exposure to different microclimatic environments. Fruit quality is of
Abdulla A. Alsadon
Six butterhead lettuce (Lactuca sativa L.) cultivars-`Sorbon' (L2130), `Donatan' (L2694), `Jessy', `Aramir', `Florian', and `Suzan'-were grown in the central region of Saudi Arabia. Following harvest and yield assessment, individual heads from each cultivar were selected randomly for subjective sensory evaluation. Among the quality attributes evaluated were color, appearance, head firmness, texture, flavor, and freedom from defects. Attributes were highly correlated with overall quality for each cultivar. `Florian' attributes were ranked high by members of an evaluation panel. In addition, `Florian' plants were among the highest yielding cultivars. `Florian' is recommended for its yield and quality features.
Renee T. Threlfall, Olivia S. Hines, John R. Clark, Luke R. Howard, Cindi R. Brownmiller, Daniela M. Segantini, and Lydia J.R. Lawless
replication at a particular intensity according to the reference points and using the universal aromatic scale. The descriptive panel identified fresh blackberry attributes for appearance (n = 8), basic tastes (n = 3), feeling factors (n = 2), aromatics (n = 8
Qinglu Ying, Yun Kong, and Youbin Zheng
. Microgreens with longer stems are normally more attractive to most consumers; therefore, plant height is one of the most important microgreen appearance qualities. In addition, plant height or stem length is an important technological quality trait. Most
L.B. McCarty, J.R. Haun, and L.C. Miller
Methods for detecting and mathematically regressing daily tall fescue (Festuca arundinacea Schreb.) leaf appearance on environmental variables are presented. Morphological stages of leaf development were quantified and the rate of leaf appearance was linearly regressed on environmental variables. The following model was developed to predict daily tall fescue leaf appearance and was successfully tested on unrelated data: Daily leaf appearance rate = 0.016 – (2.48 × 10-4 × solar radiation) + (0.015 × precipitation 2-day lag) + (0.117 × soil moisture 3-day lag) + (8.79 × 1 0-6 × maximum air temperature × solar radiation) - (3.61 × 10-' × maximum air temperature × age) + (0.00307 × minimum air temperature × precipitation) – (4.39 × 10-4 × precipitation × age), (R2 = 0.78). Growers of tall fescue and researchers will benefit in the identification of environmental characteristics and cultural practices that significantly influence leaf appearance rate.
Gisele Schoene, Thomas Yeager, and Joe Ritchie
In crop models, it is important to determine the leaf area, because the amount of light interception by leaves influences two very important processes in the plant: photosynthesis and evaporation. Leaf area is dependent on leaf appearance and expansion rates. Leaf appearance rate is driven mainly by temperature. Although the influence of temperature on leaf area development is well known for several agronomic crops, there is no information for woody ornamentals. An experiment was conducted to study the relationship between temperature and leaf appearance of container-grown sweet viburnum. Plants were grown in field conditions in Gainesville, Fla., during two growing periods (Apr. to Aug. 2004 and Aug. 2004 to Jan. 2005). Daily maximum and minimum temperature and leaf appearance were recorded. Linear regression equations were fitted to data and maximum and minimum temperature and leaf appearance were recorded. Linear regression equations were fitted to data and base temperature was assumed to be 8 °C. Thermal time (°C d) was calculated as daily average maximum and minimum air temperature minus the base temperature and was regressed against leaf number. The sum of accumulated thermal time was found to be linearly correlated with leaf number. Phyllochron, which is the thermal time between the appearances of successive leaves, was estimated 51 °C per day. The information presented in this study will be useful in modeling water use of sweet viburnum in response to environmental conditions.
D. Scott NeSmith
Different planting dates were used to study the influence of thermal time on leaf appearance rate of four summer squash (Cucurbita pepo L.) cultivars. During the first year (1991), thermal time or growing degree days (GDD) were calculated using a base temperature of 8C and a ceiling temperature of 32C for several planting dates. Leaf numbers per plant were determined every 2 to 3 days. Leaves that were beginning to unfold with a width of 2 cm or greater were included in the counts. The relationship between leaf number and GDD was established from the initial data set, and data from subsequent years were used for model validation. Results indicated that single equation could be used to predict leaf appearance of all four cultivars in response to thermal time. The response of leaf appearance to GDD was curvilinear, with a lag over the first five leaves. After five leaves, the increase in leaf number per plant was linear with increased GDD. Segmented regression with two linear functions also fit the data well. With this approach, leaf 5 was the node, and a separate linear function was used to predict the leaf number below five leaves and above five leaves. The results of this model should prove to be useful in developing a model of leaf area development, and eventually a crop growth model, for summer squash.
Luz Reyes*, Sylvia M. Blankenship*, Jonathan R. Schultheis*, and Michael D. Boyette
Sweetpotato roots, especially the cultivar Beauregard, tend to experience epidermal loss during harvest and postharvest handling which results in a less attractive product in the market. A survey study was conducted among North Carolina (N.C.) sweetpotato growers in Fall 2001 and 2002. The purpose of the survey was to gather information and try to correlate cultural practices, growing conditions and site characteristics with the occurrence of attractive roots and to define new scientific approaches to reducing epidermal loss. Samples were obtained from 42 N.C. farms. Survey field information and laboratory results were correlated to identify possible factors affecting the appearance of the roots. 1300 roots were used to measure skin adhesion, peeling susceptibility, skin moisture, skin anthocyanin and lignin content. From survey questions, 50 characteristics were defined for each sample, according to field characteristics, cultivar information, cultural practices and harvest and postharvest practices. Statistical analyses were performed to determine the relationship between the skin characteristics analyzed at the laboratory, and the survey descriptors information. Analysis of variance was used for laboratory data analysis. Person correlations were made between survey variables and laboratory characteristics. Several possible relationships between root appearance and other characteristics/practices were identified. Root skin adhesion may improve in later generations from elite propagation material. Early application of phosphate and potash fertilizers were correlated to improved root skin adhesion. There appeared to be a relationship between soil moisture at harvest time, increased lignin content in the skin and peeling susceptibility. Future areas of study were identified.