Blueberry bud freeze damage detection using optical sensors: Identification of spectral features through hyperspectral imagery

2021 ◽  
pp. 1-16
Author(s):  
Zongmei Gao ◽  
Yanru Zhao ◽  
Gwen-Alyn Hoheisel ◽  
Lav R. Khot ◽  
Qin Zhang
Keyword(s):  
Damage Detection ◽  
Optical Sensors ◽  
Vaccinium Corymbosum ◽  
Early Spring ◽  
Projection Algorithm ◽  
Phenological Stages ◽  
Freeze Damage ◽  
Cold Hardy ◽  
Successive Projection ◽  
Pertinent Feature

BACKGROUND: Highbush blueberry (Vaccinium corymbosum), the species primarily grown in the state of Washington, U.S., is relatively cold hardy. However, low temperatures in winter and early spring can still cause freeze damage to the buds. OBJECTIVE: This study intended to explore hyperspectral imaging (HSI) for detecting freeze induced bud damage. Blueberry buds (c.v. Duke) were collected over two seasons and tested in the laboratory to detect damage at four typical phenological stages. METHODS: The HSI data was acquired via line scan HSI system with spectral wavelength ranging from 517 to 1729 nm for buds grouped into either normal or injured mortalities. The successive projection algorithm was employed for pertinent feature wavelength selection. Analysis of variance and linear regression were then applied for evaluating sensitivity of feature wavelengths. RESULTS: Overall, five salient wavelengths (706, 723, 872, 1384, and 1591 nm) were selected to detect bud freeze injury. A quadratic discriminant analysis method-based analysis verified reliability of these five wavelengths in bud damage detection with overall accuracy in the ranges of 64 to 82%for the test datasets of each stage in two seasons. CONCLUSIONS: This study indicated potential of optical sensing to identify the injured buds using five salient wavelengths.

The effects of burning on Festuca hallii in the parklands of central Alberta

1995 ◽  
Vol 73 (6) ◽  
pp. 937-942 ◽  
Author(s):  
Heather Sinton Gerling ◽  
Arthur W. Bailey ◽  
Walter D. Willms
Keyword(s):  
Standing Crop ◽  
Growing Season ◽  
Early Spring ◽  
Leaf Length ◽  
Tiller Number ◽  
Phenological Stages ◽  
University Of Alberta ◽  
Festuca Hallii ◽  
Tiller Density ◽  
The University

The response of Festuca hallii (Vassey) Piper to time of burning was examined on the Festuca–Stipa grasslands of the Aspen Parklands at the University of Alberta Ranch located 150 km southeast of Edmonton, Alberta. Two defoliation treatments (burning and mowing) were examined on five dates in 1978 (8 April, 27 April, 1 June, 31 July, and 18 October), corresponding to different phenological stages of F. hallii. Burning and mowing reduced the standing crop of F. hallii produced in the first growing season after treatment, but tiller densities increased. Defoliation in early spring (8 April) had little effect on the standing crop; apparently the increase in tiller density compensated for the reduction in tiller length. Inflorescence density also increased following burning or mowing from 8 April to 1 June. Soil temperature (3 cm deep) on previously burned or mown sites was greater than on the control the year after treatment. Festuca hallii tolerates single burns at any time of the year, but early spring fires have the greatest benefits by increased tillering and standing crop. Key words: standing crop, tiller number, leaf length, litter, defoliation, mowing.

Pollen development in relation to phenological stages of inflorescence expansion in Amelanchier alnifolia (saskatoon), with a comparison with buds forced out of dormancy

1999 ◽  
Vol 77 (2) ◽  
pp. 262-268
Author(s):  
Michael J Sumner ◽  
William R Remphrey ◽  
Richard Martin
Keyword(s):  
Time Frame ◽  
Early Spring ◽  
Flower Buds ◽  
Flower Bud ◽  
Phenological Stages ◽  
Inflorescence Development ◽  
Amelanchier Alnifolia ◽  
Bud Development ◽  
Internal Development ◽  
Flower Bud Development

A relationship was developed between phenological stages of inflorescence expansion and the internal development of pollen within the anther of Amelanchier alnifolia Nutt. flowers. The major microscopic events associated with microsporogenesis and microgametogenesis were correlated with seven stages of external inflorescence development in both natural buds and those forced from dormancy in different concentrations of gibberellin at various times of the year. In fall and early spring, it was found that gibberellin at a concentration of 2.5 mg/L forced buds to produce inflorescences that most resembled those from natural field populations. However, it was not possible to force flower buds to develop all the way to anthesis. Flower bud development stopped when the pollen was at the binucleate stage. Despite this limitation, the ability to force buds increases the time frame for the study of many aspects of the reproductive biology of A. alnifolia.Key words: microsporogenesis, microgametogenesis, gibberellin, GA, flowering.

Non-destructive freeze damage detection in oranges using machine vision and ultraviolet fluorescence

2008 ◽  
Vol 48 (3) ◽  
pp. 341-346 ◽  
Author(s):  
D.C. Slaughter ◽  
D.M. Obenland ◽  
J.F. Thompson ◽  
M.L. Arpaia ◽  
D.A. Margosan
Keyword(s):  
Machine Vision ◽  
Damage Detection ◽  
Freeze Damage ◽  
Non Destructive

scholarly journals Effect of Floricane Number in `Marion' Trailing Blackberry. I. Primocane Growth and Cold Hardiness

1997 ◽  
Vol 122 (5) ◽  
pp. 604-610 ◽  
Author(s):  
Jessica M. Cortell ◽  
Bernadine C. Strik
Keyword(s):  
Cold Hardiness ◽  
Fruit Production ◽  
Additional Treatment ◽  
First Flush ◽  
Phenological Stages ◽  
Absolute Growth Rate ◽  
Whole Plant ◽  
Absolute Growth ◽  
Cold Hardy ◽  
Controlled Freezing

In Spring 1993 and 1994, mature trailing `Marion' blackberries (Rubus L. subgenus Rubus Watson) were pruned to 0, 4, 8, and 12 floricanes/plant. An additional treatment of 0 floricanes with early (30 cm) primocane topping and pruning was included. Primocane length was measured from emergence in April until growth cessation at the end of October on individual canes and for the whole plant. In January 1994 and 1995, cane cold hardiness was evaluated by controlled freezing. In 1993, plants without floricanes produced more primocanes and branches with an increased total length at the end of the season than plants with floricanes. However, there were no significant differences in primocane length among treatments in 1994. In all treatments, the absolute growth rate (AGR), on a length basis, of primocanes occurred in flushes of rapid growth followed by slower growth throughout the season. Plants without floricanes had a significantly greater AGR than plants with floricanes on five dates in 1993. In 1994, there was no effect of floricane number per plant on AGR of primocanes over the season and the growth peaks were not as distinct. When comparing primocane elongation rate at three phenological stages in 1993, plants with no floricanes had a significantly higher total primocane growth per day during fruit production and from harvest to length cessation. The following year, plants with no floricanes had the highest rate of growth before bloom and a trend toward greater growth during fruit production. After fruit production, there were no differences in AGR between the treatments. Plants with floricanes produced a second flush of primocanes, while plants with no floricanes produced only one flush of primocanes. Primocane length of the first flush (averaged for 4-, 8-, and 12-floricane plants) was significantly different from the second flush at all dates during the season except for the final end of season measurement date. Primocanes pruned at 30 cm did not produce significantly more branches than unpruned primocanes on plants without floricanes. Plants without floricanes produced primocanes that were significantly more cold hardy (lower LT50) in 1994 and 1995 than plants with floricanes.

scholarly journals (236) Evaluation of Styrax japonicus for Time of Budbreak and Susceptibility to Spring Freeze Damage

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1002B-1002 ◽  
Author(s):  
Sandra Reed
Keyword(s):  
United States ◽  
Genetic Variability ◽  
Weather Conditions ◽  
The United States ◽  
Early Spring ◽  
Late Winter ◽  
Ornamental Tree ◽  
Good Consistency ◽  
Spring Temperatures ◽  
Freeze Damage

Japanesesnowbell(Styrax japonicus Sieb. & Zucc.) is an outstanding small ornamental tree that is underutilized in the United States. Many of the cultivars of this Asian native frequently suffer spring freeze damage, especially when grown in the areas of the country that routinely experience dramatic fluctuations in late winter and early spring temperatures. The objectives of this study were to determine if there was variability within S. japonicus for time of budbreak and if this variability could be used for selecting plants with reduced susceptibility to spring freeze damage. In 1998, 224 open-pollinated seedlings were planted in the field. Percent budbreak was evaluated weekly during a 6-week period in Spring 1999 and 2000. While weather conditions varied greatly between the 2 years, there was good consistency between mean budbreak ratings in 1999 and 2000. There was a 4-week difference between the earliest and latest plants to break dormancy. Based on the 1999 and 2000 data, 28 plants were selected and propagated. A replicated trial involving these selections and three cultivars was carried out in 2002, 2003, and 2004. All of the selections broke bud later and suffered less freeze damage than `Emerald Pagoda' and `Carillon', but many performed similarly to `Pink Chimes'. Variation in height, width, caliper, and canopy shape was observed among the selections. There is an opportunity to utilize the genetic variability in S. japonicus for developing cultivars with reduced susceptibility to spring freeze damage.

scholarly journals High-Throughput Phenotyping Approach for the Evaluation of Heat Stress in Korean Ginseng (Panax ginseng Meyer) Using a Hyperspectral Reflectance Image

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5634
Author(s):  
Eunsoo Park ◽  
Yun-Soo Kim ◽  
Mohammad Kamran Omari ◽  
Hyun-Kwon Suh ◽  
Mohammad Akbar Faqeerzada ◽  
...  
Keyword(s):  
Heat Stress ◽  
Discriminant Analysis ◽  
Panax Ginseng ◽  
Near Infrared ◽  
Short Wave ◽  
Hyperspectral Images ◽  
Projection Algorithm ◽  
Validation Data ◽  
Linear Discriminant ◽  
Successive Projection

Panax ginseng has been used as a traditional medicine to strengthen human health for centuries. Over the last decade, significant agronomical progress has been made in the development of elite ginseng cultivars, increasing their production and quality. However, as one of the significant environmental factors, heat stress remains a challenge and poses a significant threat to ginseng plants’ growth and sustainable production. This study was conducted to investigate the phenotype of ginseng leaves under heat stress using hyperspectral imaging (HSI). A visible/near-infrared (Vis/NIR) and short-wave infrared (SWIR) HSI system were used to acquire hyperspectral images for normal and heat stress-exposed plants, showing their susceptibility (Chunpoong) and resistibility (Sunmyoung and Sunil). The acquired hyperspectral images were analyzed using the partial least squares-discriminant analysis (PLS-DA) technique, combining the variable importance in projection and successive projection algorithm methods. The correlation of each group was verified using linear discriminant analysis. The developed models showed 12 bands over 79.2% accuracy in Vis/NIR and 18 bands with over 98.9% accuracy at SWIR in validation data. The constructed beta-coefficient allowed the observation of the key wavebands and peaks linked to the chlorophyll, nitrogen, fatty acid, sugar and protein content regions, which differentiated normal and stressed plants. This result shows that the HSI with the PLS-DA technique significantly differentiated between the heat-stressed susceptibility and resistibility of ginseng plants with high accuracy.

scholarly journals Cold Hardiness and Options for the Freeze Protection of Southern Highbush Blueberry

Agriculture ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 9 ◽  
Author(s):  
Erick D. Smith
Keyword(s):  
Cold Hardiness ◽  
Fruit Set ◽  
Vaccinium Corymbosum ◽  
Early Spring ◽  
Climatic Conditions ◽  
Critical Temperatures ◽  
Overhead Irrigation ◽  
Frost Protection ◽  
Southern Highbush ◽  
Freeze Protection

Southern highbush blueberries (SHB; Vaccinium corymbosum interspecific hybrid) are a low chill species of blueberry that are commercially grown in sub-tropical climates. Due to the nature of SHB, the flowering and fruit set occur in mid-winter to early spring and are susceptible to freeze damage. The most effective use of freeze protection is based on climatic conditions. Identification of advective or radiative freeze, intensity of the freeze event, and the equipment deployed are the key elements for deciding if the crop can be protected and justifying the expense to operate the system. Of the various methods used in frost protection, applying overhead irrigation water is the most promising. During a freeze event, an application of 6.3 mm ha−1 (0.10 in A−1) of water per hour is required to protect blueberries from −2.8 °C (27 °F) temperature with winds from 0 to 16 km h−1 (0 to 10 mph). This is 25.4 kL h−1 ha−1 (2715 gal h−1 A−1) of water. Overhead irrigation freeze protection is dependent on large volumes of water. This paper will review methods of freeze/frost protection, importance of weather patterns, and critical temperatures based on phenology of flowering to fruit set.

Simulation of salmonberry and thimbleberry population establishment and growth

1993 ◽  
Vol 23 (10) ◽  
pp. 2194-2203 ◽  
Author(s):  
Bruce D. Maxwell ◽  
John C. Zasada ◽  
Steven R. Radosevich
Keyword(s):  
Canopy Cover ◽  
Early Spring ◽  
Early Summer ◽  
Phenological Stages ◽  
Simulation Accuracy ◽  
Life History Stages ◽  
Demographic Processes ◽  
Species Specific ◽  
Summer Fruit ◽  
Number Of Individuals

A salmonberry (Rubusspectabilis Pursh) and thimbleberry (Rubusparviflorus Nutt.) population simulation model was developed and compared with field observations for verification and validation. The species-specific influence of different phenological stages (early spring bud break, early summer fruit set, and fall senescence), different environments (at different sites), and intraspecific density on demographic processes was incorporated into the model. The model predicts the number of individuals in different life-history stages at three phenological stages during a growing season. Simulations were most accurate when compared with low genet density planted populations. Salmonberry populations on a moist site were most accurately simulated. Thimbleberry simulation accuracy was reduced by poor prediction of sprout densities. Salmonberry and thimbleberry population response to an application of glyphosate was simulated and compared with observed canopy cover for 3 years following application. The simulated response was accurate for the 1st year following application, but did not account for continued canopy cover in the observed populations. Salmonberry canopy cover and mean ramet height in response to manual cutting at three phenological stages was also simulated. The model simulations indicated that the most prolonged reduction in salmonberry cover followed cutting at the reproductive stage of growth.

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