Progress 01/01/07 to 12/31/11
Outputs
OUTPUTS: Integrative or high-impact learning is intentionally connected learning across courses and disciplines, overtime, and between campus and community to prepare students for making informed decisions in their personal, professional, and civic life. Student Learning Outcomes can be demonstrated by intellectual, personal and disciplinary development through understanding and connecting knowledge from multiple fields, applying theory and practice to various settings, utilizing diverse and even contradictory views, and understanding issues and positions contextually to deal with adult work and life challenges.This work investigates whether student skill acquisition and cognitive development is enhanced through integrative learning in comparison to more traditional curricular designs over the relatively short duration of a baccalaureate degree program. Two survey instruments were used to assess students' skill acquisition, cognitive development, and ability to connect knowledge: The Learning Environment Preferences (LEP tool, Perry 1999) instrument designed to assess personal development of undergraduate students. The LEP tool addresses five domains: course content, roles of instructors and peers, classroom atmosphere and activities; and course evaluation to measure student learning preferences. It uses Perry's model of college student development positions to categorize a student's ability to make meaning from the context in which he/she exists and provides an understanding of whether curricular practices affect students' ability to construct meaning from complex situations based upon their personal rationalization or if they rely on others to create this meaning for them. The Cognitive Development instrument (CD tool) measures students' cognitive development with a paper and pencil Piagetian test to determine their development from the concrete operational stage (requires real objects, events, or situations to find meaning) to formal operational stage (abstract and inventive thinker) of cognitive development. Four questions were added for this research to measure interpersonal development. Surveys were administered in discipline-oriented freshmen and senior level classes to a total of 291 students. However, there was considerable diversity in student class level and majors. Approximately 55% of respondents were majors in horticulture, PDC, and CARRS. The remaining students were from other majors within CANR (ca. 34%) or were officially undecided majors (ca. 10%). Data generated from the LEP and CD tools are categorized into three positions: Low (Perry Levels 1, 2, 2-3 and Piaget Structure Preoperational); Medium (Perry Levels 3, 3-4, 4 and Piaget Structure Concrete Operational); and High (Perry Levels 4-5, 5, and above, and Piaget Structure Formal Operational). The position scores are expressed in terms of percentages, with the scores totaling 100 percent. Data for each subject is integrated to produce a Cognitive Complexity Index (CCI) score. This score is a used as a continuous scale from 200 - 500 to indicate intellectual development. The CCI is a general indicator of increasing cognitive complexity or intellectual development. PARTICIPANTS: Individuals who worked on this project included scientists and academic instructors from multiple disciplines that included agronomy, viticulture, horticulture and statistics. The project encompassed testing of remote sensing as a tool to detect plant stress in multiple plant systems and to evaluate the training of undergraduate students in terms of cognitive development using high impact learning environments. TARGET AUDIENCES: Target audiences included agronomic and horticulture producers and educators to better understand the use of remote sensing as a management tool and a model for high impact learning opportunities. PROJECT MODIFICATIONS: The project was modified over its duration to reflect responses to different needs of clientele and educational opportunities.
Impacts
In all academic ranks (1 through 4) a few students scored in the Low categories of Perry's Student Development (Levels 1&2) and Piaget's Pre-operational stage of development. There was a gradual decline in students who scored the Medium stages of development in both Perry's (Levels 3&4) and Piaget's (Concrete Operational) models for student rank from freshmen to seniors (years 1-4). There was a general trend for an increase in students reaching Piaget's Formal Operational level of cognitive development from freshmen to seniors (years 1-4). Few students in the sample group attained the High level of Perry's developmental stages within any of the 4 years of student degree designation. When Interpersonal Development is compared to intellectual development all students, regardless of their developmental stage or rank prefer to work as individuals on projects and compartmentalize their relationships into different groups that do not overlap. Students in the Low and Medium developmental stages differ with students in the High developmental stage in terms of how they approach project organization, assignment of tasks and working through the completion of projects. Based on the outcomes from these survey instruments, it's no surprise students are not ready for employment that requires solving problems with multiple solutions under real world situations. Students need exposure to more learning experiences that require them to process information that is dramatically different from the mental structure they currently have, so they can incorporate it into their evolving mental structure. Piaget's theory suggests, if information is not presented in this way it will not make sense and will be rejected. If the individual is forced to use the information without expanding their developmental level they will memorize it even though the meaning is not understood. If the new information requires formal operational thinking and the student is otherwise ready then the formal operational stage can be formed.
Publications
- No publications reported this period
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: This project has moved to the phase of testing ways to validate the effectiveness of high-impact practices over a broad cross section of students within the agriculture sciences. We will test whether high-impact learning based curricula within agriculture-based subject areas enhance student learning and cognitive development over the relatively short duration of a baccalaureate degree (i.e., between freshmen and senior year experiences). Further, we will investigate whether high-impact learning based curricula are an essential approach to reaching the goal of strengthening the agricultural professional workforce through increased graduation of skill-based graduates that possess the cognitive ability and critical thinking to find answers to current and future problems. The work will develop a model that documents the use of high-impact practices at the curricular level and assess student intellectual development in response to learning at the cohort level to compare participation in high-impact practices with student development. This work will generate a protocol for analyzing and synthesizing the quantitative and qualitative data delivered by the model (Figure 1). The proposed study will test whether these assumptions improve the number and quality of baccalaureate graduates in the food and agricultural sciences disciplines. PARTICIPANTS: Projector Director: N. Suzanne Lang, Department of Horticulture, MSU Co-Project Directors: Patricia Crawford, School of Planning, Design, and Construction; Patricia Machemer, School of Planning, Design, and Construction; and Michael Orth, Department of Animal Science. TARGET AUDIENCES: The anticipated audience for this project will include all individuals and institutions that are interested in providing learning environments that prepare their graduates for the complexity of future careers as skilled professionals. The differences among student learning outcomes within traditional segregated discipline oriented curricula and those learning outcomes of students immersed in unit level high-impact learning curricula. Student learning outcomes of intellectual and personal development will be assessed with standardized quantitative tools. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Results from this work will include: model for evaluation of high-impact learning; recommendations for curriculum design and instructional methods in the food and agricultural sciences; publications in peer-reviewed journals on the research results; and adoption of curriculum assessment process (Assessment Model) by other internal and external programs and institutions Expected Outcomes from this work will include:a better understanding of the costs and benefits of high-impact learning practices in higher education curricula; increased knowledge about the impacts of high-impact learning practices on student learning outcomes; and better understanding of undergraduate intellectual and cognitive development and learning
Publications
- No publications reported this period
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Use of remote sensing in development of site-specific management enables informed choices for selection of land as well as sustainable production systems (such as remote sensing) has been assumed to occur on an as needed basis. New studies have been initiated to develop research protocol for assessing student integrative learning within curricula that incorporate these types of multi-decision making approaches. Experiments have been designed as six-year longitudinal studies with pre- and post-testing of undergraduate students as they progress from their initial experiences in their curriculum to final semester of their matriculation year to assess student-learning outcomes associated with integrative learning. Integrative learning uses real-world problems such as development of site-specific management, unscripted and sufficiently broad to require multiple areas of knowledge and multiple modes of inquiry, offering multiple solutions and benefiting from multiple perspectives. Integrative learning outcomes can be demonstrated in terms of intellectual, personal, and disciplinary development through understanding and connecting knowledge from multiple fields and understanding issues and positions contextually. Surveys (Perry) for assessing student development categorize student learning into the following preferences: what to learn (a focus on facts, tendency toward passive learning); how to learn (a focus on methods of learning/problem solving); how to think (a focus on independent thinking, integration of content, tendency to reject rote learning); and how to judge (a focus on synthesis of different ideas, begins to judge ideas and quality of evidence, self-directed learning). The researchers will utilize the studies to gain a better understanding of the effects of integrative learning on undergraduate learning outcomes of future producers and leaders of sustainable programs. PARTICIPANTS: Patricia Crawford, School of Planning, Design and Construction, Michigan State University; Patricia Mechemer, School of Planning, Design and Construction, Michigan State University; Glenn Sterner, Department of Community, Agriculture, Recreation,Resource Studies, Michigan State University TARGET AUDIENCES: Higher Education Educators, Higher Education Administrators, Industry educators and Producers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Preliminary data suggest that 48% of the students that were surveyed have a preference for the "what to learn" level of learning; 24% have a preference for the "how to learn" level; 10% have a preference for the " how to think" level; 3% for the "how to judge" level; and the remaining students (15%) did not indicate they have a specific preference, having equal scores across all levels of learning. Given that 88% of the students surveyed were freshman or sophomores, these results support earlier research that indicate beginning students typically score in the lower learning preference levels. It is anticipated that surveys of more senior students that have been exposed to integrative learning experiences achieve higher levels of intellectual development.
Publications
- No publications reported this period
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Use of remote sensing in development of site-specific management enables informed choices for selection of land for wine grape-producing sites under cool climate growth conditions. The first research priority of the Michigan Grape and Wine Industry Council is the development of GIS/GPS maps of current and potential wine grape-producing regions across the state. Due to the key role climate plays in determining locations for premium viticultural production, quantification and use of meso- and microclimate data have been identified as the next steps in mapping potential viticulture sites. Air temperature data from established weather stations (National Climatic Data Center), remote sensing images including but not limited to Landsat, NOAA (AVHRR) and TERRA (MODIS) satellites, and temperature micro-sensors installed at multiple locations within sites considered important for temperature model development will be incorporated into the model GIS/GPS maps. PARTICIPANTS: Sasha Kravchenko, Paolo Sabbatini, Ron Perry, Jeff Andresen, Jiaguo Qi, Michigan Grape and Wine Council TARGET AUDIENCES: Michigan wine industry. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
In current research GIS/GPS based maps have been created by combined data from multiple scales and resolutions, including: topographical data (terrain, slope and aspect) based on digital elevation model (DEM) data of 30x30 m resolution; soil information from Soil Survey Geographic data (SSURGO/USDA-NRCS) of at least 100X100m resolution; and macro climate data based on large scale regional trends.
Publications
- No publications reported this period
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Progress 01/01/07 to 12/31/07
Outputs
This work proposes to develop remote sensing monitoring that Michigan turfgrass managers can use to reduce adverse impact of plant stress. Leaf reflectance, total daily light energy received and metabolic processes that control growth and photosynthetic capacity in turfgrasses under shade conditions were investigated. Low DLI (daily light integral, mol/m/d), or shade, reduces turfgrass growth and quality due to direct relationships between growth of turfgrasses and the reduced carbohydrates produced by photosynthesis. Greenhouse growth floriculture crops require a minimum DLI of 10 moles per day to support growth and development. It has been estimated that nearly 25% of existing turfgrasses are maintained and grown well below 30 mol/m2/d. Determining a required light energy threshold for turfgrass growth under limited light is important to understand when low light stress is induced. Light response curves of two fine leaf fescue turfgrass species well adapted to shade
(chewings fescue, Festuca rubra v. commutata SR5100 and creeping red fescue, Festuca rubra v. rubra Dawson) as well as a "shade tolerant" cultivar of Kentucky bluegrass(Poa pratensis Cynthia) were grown under three low DLI levels to identify maximum assimilation (Amax) and light compensation points (LCP). Low DLI treatments included 10, 8, and 4 mol/m2/d. Growth and metabolism measurements included clipping weights (g/m2) and light response curves (0 umol/m2/s to beyond light saturation). Under 10 and 8 mol m-2 d-1 clipping wt increased over time for all species, while turf grown under 4 mol/m2/d produced significantly lower clipping wt over the same period. Clipping weight and DLI (10 and 8 mol/m2/d) were positively correlated, suggesting that DLI directly influenced growth of these turfgrass species. DLI levels of 10 and 8 mol m-2 d-1 were sufficient light energy to maintain Amax at levels that supported growth. There were no significant differences in LCP between weeks or species.
However over time plants grown under 10 and 8 increased in LCP and assimilation rates. Turfgrass response to the three DLI was similar, but the change in specific dry wt and the responses to light were species specific. The varied responses suggested differences in the metabolic efficiency among the three turfgrasses to use available light, as well as a difference in their respective ability to acclimate to shaded conditions. This research suggests the threshold for minimum light energy to support growth in turfgrass species appears to be similar to many other plant species. Below the threshold DLI of 8 mol/m2/d turfgrass was not able to maintain sufficient photosynthetic capacity to maintain growth.
Impacts
This work proposes to develop remote sensing monitoring that Michigan turfgrass managers can use to reduce adverse impact of plant stress. The primary approach to accomplish the objective is to measure spectral reflectance differences and metabolic processes in response to stress. Differences in spectral curves associated with specific alterations in leaf metabolism due to isolated stresses will be explored. Spectral differences hold potential for quantifying the defined wavelengths unique to specific plant stress conditions. Non-destructive monitoring strategies could then be developed for detecting and quantifying stress to allow managers and growers to target inputs, increasing economic efficiency and decreasing adverse environmental impact by reducing non-target applications.
Publications
- Valentino,T.E. and Lang,N.S. 2007. Daily light integral influences turfgrass growth and photosynthesis under shade. ASA-CSSA-SSSA Proceedings. New Orleans, LA.
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Progress 01/01/06 to 12/31/06
Outputs
This work proposes to develop remote sensing monitoring tools that Michigan turfgrass managers can use to prevent the adverse impact of plant stress, before the stress is visible using conventional monitoring methods. A primary approach to accomplish this objective is to look at leaf spectral reflectance and metabolic processes in response to abiotic stresses. Differences in spectral curves associated with specific alterations in leaf metabolism due to isolated stresses will be explored and identified, because spectral differences hold potential for quantifying the defined wavelengths unique to specific abiotic stress. Once specific wavelengths of reflected light are identified, the next step will the development of inexpensive methods to enable Michigan growers to detect spatially and temporally variable stress in managed turfgrass sites to manage inputs in support of sustainable best management practices. Additionally, this work will improve the understanding of how
light and temperature interact to influence horticultural crop productivity, while addressing factors to improve environmental quality by directing inputs when and where they are required within a site. This research will enable Michigan turfgrass managers to determine the presence of a quality-limiting factor occurring prior to the full adverse impact of the stress factor. The stress factors that are targeted vary throughout the growing season (temporally) and within a given field (spatially). The non-destructive monitoring strategies to be developed for detecting and quantifying stress will allow turfgrass managers and growers to target their inputs, increasing the economic efficiency of management, and concurrently decreasing adverse environmental effects by reducing non-target applications. Traditional outreach efforts will be made in the form of talks at grower meetings, at regional and national meetings, talks at regional grower field days, and a site on the World Wide Web. In
addition, much of the research for this project will be verified under real-world conditions. Pending the results, key growers, and/or consultants would be asked to participate in field validation work on leaf spectral reflectance monitoring tools and working with web-based models to direct spatial and temporal canopy management. Key research personnel on the project have the expertise and opportunities to implement information developed from this research.
Impacts
This work proposes to develop remote sensing monitoring tools that Michigan turfgrass managers can use to prevent the adverse impact of plant stress, before the stress is visible using conventional monitoring methods. A primary approach to accomplish this objective is to look at leaf spectral reflectance and metabolic processes in response to abiotic stresses. Differences in spectral curves associated with specific alterations in leaf metabolism due to isolated stresses will be explored and identified, because spectral differences hold potential for quantifying the defined wavelengths unique to specific abiotic stress. Once specific wavelengths of reflected light are identified, the next step will the development of inexpensive methods to enable Michigan growers to detect spatially and temporally variable stress in managed turfgrass sites to manage inputs in support of sustainable best management practices. The non-destructive monitoring strategies to be developed for
detecting and quantifying stress will allow turfgrass managers and growers to target their inputs, increasing the economic efficiency of management, and concurrently decreasing adverse environmental effects by reducing non-target applications.
Publications
- Valentino, T.E. 2006. Physiological and metabolic effects of supplemental fructose applied to various turfgrasses under shade. M.S. Thesis, Michigan State University.
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Progress 01/01/05 to 12/31/05
Outputs
Use of remote sensing in the development of site-specific management will enable producers to stop managing based on averages. To fully utilize current tools we need to know what is happening and when in order to determine when plant stress impacts yield and quality. Analyzing plant environmental stress based on spatial (site-specific) variation can be useful to crop management because it allows for the quantification of stress impact on crop productivity. Work was initiated to combine leaf reflectance analysis with on going clonal trials to determine which grapes are best adapted to Michigan light and water availabilities. Different shoot density, training and pruning systems were established to test which system could give grape canopy architecture the greatest efficiency in absorbing light and handling water stress. Preliminary statistical analysis indicated that both varieties and different treatments applied in certain parts of the experiment had a statistically
significant effect on the studied remote sensing indexes. These effects overlay the natural spatial variation that exists in the studied site. Strong spatial correlation in distribution of the remote sensing indexes indicates that there are well defined patterns of higher/lower remote sensing index values in the studied site. The patterns are probably caused by variations in topographical features, soil properties, nutrient and moisture availabilities and other factors that affect plant growth and development. Impact of these factors varies during the growing season, possibly being much stronger in summer than in fall. Additional work on apple and potato suggest that the normalized difference vegetation index (NDVI) values calculated from leaf spectral reflectance shows promise for the nondestructive measurement for N management on a spatial basis.
Impacts
The overall objective of this research is to develop nondestructive monitoring techniques for plant stress prior to visible detection using current techniques. Detection should provide real time information on stress, which varies based on location within a site and/or time of year. This will allow the use of management inputs that are both location and time responsive, at a stage that would reduce the adverse impact of the plant stress on crop yield and quality. During the 2003 growing season we tested whether leaf reflectance can detect and quantify plant stress based on location within the vineyard in Vitus vinifera at different stages of growth and development. Preliminary statistical analysis indicates variety and treatments (trellis system and crop load/canopy ratios) had a significant effect on reflectance indexes. These effects overlay the natural spatial variation that exists within the site. The strong correlation in the distribution of the plant stress
indexes derived from leaf reflectance indicate that there are well defined patterns of variation in water stress, photosynthetic efficiency and overall plant stress across the research vineyard. The patterns are probably caused by variations in topographical features, soil properties, nutrients and moisture availabilities. Based on the detection of these stresses, inputs can be targeted so that resource use is the most effective with reduced negative impacts on the environment.
Publications
- Davenport, J.R., Perry, E.M., Lang, N.S. and Stevens, R.G. 2005. Leaf spectral reflectance for non-destructive measurement of plant nutrient stress. HortTechnology 15:31-35.
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Progress 01/01/04 to 12/31/04
Outputs
Use of remote sensing in the development of site-specific management will enable producers to stop managing based on averages. To fully utilize current tools we need to know what is happening and when in order to determine when plant stress impacts yield and quality. Analyzing plant environmental stress based on spatial (site-specific) variation can be useful to crop management because is allows for the quantification of stress impact on crop productivity. Work was initiated to combine leaf reflectance analysis with on going clonal trials to determine which grapes are best adapted to Michigan light and water availabilities. Different shoot density, training and pruning systems were established to test which system could give grape canopy architecture the greatest efficiency in absorbing light and handling water stress. Preliminary statistical analysis indicated that both varieties and different treatments applied in certain parts of the experiment had a statistically
significant effect on the studied remote sensing indexes. These effects overlay the natural spatial variation that exists in the studied site. When treatment/variety effects are combined with underlying spatial variation, a distribution of the measured data values in the studied site does not clearly reflect either treatment/variety effect or the natural variability. However, strong spatial correlation in distribution of the remote sensing indexes indicates that there are well defined patterns of higher/lower remote sensing index values in the studied site. The patterns are probably caused by variations in topographical features, soil properties, nutrient and moisture availabilities and other factors that affect plant growth and development. Impact of these factors varies during the growing season, possibly being much stronger in summer than in fall.
Impacts
The overall objective of this research is to develop nondestructive monitoring techniques for plant stress prior to visible detection using current techniques. Detection should provide real time information on stress, which varies based on location within a site and/or time of year. This will allow the use of management inputs that are both location and time responsive, at a stage that would reduce the adverse impact of the plant stress on crop yield and quality. During the 2003 growing season we tested whether leaf reflectance can detect and quantify plant stress based on location within the vineyard in Vitus vinifera at different stages of growth and development. Preliminary statistical analysis indicates variety and treatments (trellis system and crop load/canopy ratios) had a significant effect on reflectance indexes. These effects overlay the natural spatial variation that exists within the site. The strong correlation in the distribution of the plant stress
indexes derived from leaf reflectance indicate that there are well defined patterns of variation in water stress, photosynthetic efficiency and overall plant stress across the research vineyard. The patterns are probably caused by variations in topographical features, soil properties, nutrients and moisture availabilities. Based on the detection of these stresses, inputs can be targeted so that resource use is the most effective with reduced negative impacts on the environment.
Publications
- Silbernagel, J. and N.S. Lang. 2003. Spatial distribution of environmental stress and greenness in Concord grapevines. Ecological Indicators 2:271-286.
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Progress 01/01/03 to 12/31/03
Outputs
During 2003 we tested leaf reflectance for detecting and quantifying plant stress within the vineyard of wine grapes managed under different trellis systems, locations within the block, and crop load/canopy ratios. Data included GPS coordinates of 200 sample plants, elevation differences of site, leaf reflectance measured at specific stages of canopy and crop development(NB, near bloom, AB,after bloom, NV, near veraison, and NH, near harvest), cluster number, fruitfulness (lb/fruit/node), and crop load (yield/pruning wt/vine). Analysis includes reflectance curve analysis for plant stress, spatial analysis of reflectance stress indices, and correlations between treatment/variety and growth parameters on a spatial basis. Full spectrum leaf reflectance curves were analyzed for the following stress indices: canopy water stress using the Water Band Index (WBI); efficiency of photosynthesis (a measure of how much light energy is used for photosynthesis) using the
Photosynthetic Reflectance Index (PRI);and leaf reflectance after wavelengths absorbed by chlorophyll as an indication of plant stress using the Red-edge Vegetation Stress Index (RVSI). Statistical analysis indicates variety and treatments (trellis system and crop load/canopy ratios) had a significant effect on reflectance indexes. These effects overlay the natural spatial variation that exists within the site. For all indexes there is a strong spatial continuity in data distribution in the studied vineyard. For all indexes the correlation between data values is the strongest at the minimum separation distance (5m) between points and as distance between data points increases, the correlation between location and data values decreases. The results indicate that over the growing season the strength of the spatial continuity of the individual plant stress indexes vary. For each of the indexes, spatial continuity is stronger at NB and AB than in the NV or NH. In PRI correlogram values
(correlation coefficients) at 5 m apart are 0.84 and 0.64 for NB and AB time intervals, respectively. However, at NV and NH, the values are 0.37 and 0.50. For WBI, the distance at which the measurements are spatially correlated are only at 5m and 10m for NV and NH and becomes not significant at 20 m. The range of spatial correlation for the NB data is much larger, for both PRI and RVSI with correlation coefficients statistically significant up to 40 m distances. The strong correlation in the distribution of the plant stress indexes derived from leaf reflectance indicate that there are well defined patterns of variation in water stress, photosynthetic efficiency and overall plant stress across the research vineyard. The patterns are probably caused by variations in topographical features, soil properties, nutrients and moisture availabilities. Further analysis will included whether the natural spatial variations within the vineyard can be eliminated from the comparisons between wine
grape varieties and the imposed treatments. Differences in treatment will be correlated to plant stress indexes to test if they can be used as a valid indication of canopy status during the growing season.
Impacts
The overall objective of this research is to develop nondestructive monitoring techniques for plant stress prior to visible detection using current techniques. Detection should provide real time information on stress, which varies based on location within a site and/or time of year. This will allow the use of management inputs that are both location and time responsive, at a stage that would reduce the adverse impact of the plant stress on crop yield and quality. During the 2003 growing season we tested whether leaf reflectance can detect and quantify plant stress based on location within the vineyard in Vitus vinifera at different stages of growth and development. Preliminary statistical analysis indicates variety and treatments (trellis system and crop load/canopy ratios) had a significant effect on reflectance indexes. These effects overlay the natural spatial variation that exists within the site. The strong correlation in the distribution of the plant stress
indexes derived from leaf reflectance indicate that there are well defined patterns of variation in water stress, photosynthetic efficiency and overall plant stress across the research vineyard. The patterns are probably caused by variations in topographical features, soil properties, nutrients and moisture availabilities. Based on the detection of these stresses, inputs can be targeted so that resource use is the most effective with reduced negative impacts on the environment.
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
The objective of this research is to assemble full-spectrum leaf reflectance curves of specific commercial grape varieties grown in Michigan, associated with abiotic stress to identify and quantify spectral differences for integrated management programs in cool climate grape production systems. Studies have involved greenhouse grown potted vines (wine grape varieties: Cabernet Franc, Chambourcin, Chadonel, Chardonnay, Foch, Frontenac, Pinot Gris, Riesling, Seyval, Vignoles; and juice grape varieties: Concord, Niagra) were exposed to abiotic stress (nutrient and water stress). Controls vines were maintained under optimal conditions. Full-spectrum leaf-reflectance (FieldSpec JR, Analytical Spectral Devices) measurements at (450 to 2500 nm)were recorded at regular intervals after abiotic stress was imposed(prior to and after symptom development)to determine if stresses were detected and quantified using spectral signatures for grapes with different morphological
characteristics. Full-spectrum reflectance curves for each level of stress were collected at discrete intervals and used to construct a 'spectral library' of reflectance measurements. The corresponding metabolic status of grape organs were verified by evaluating comparisons between photosynthestic responses, as well as spectral curves of stressed and non-stressed organs and/or canopies. Differences in spectral curves will allow for isolation and quantification of the stress based on the specific spectra unique to each stress. Data analysis of rsults are on going:1)Water Band Index (WBI=R900/R970; examines the correlation between water content, normalized vegetation index (NDVI) and equivalent water thickness; WBI values are correlated with leaf water content & values are inversely related to water-induced stress;2)Photosynthetic Reflectance Index(PRI)=(R531 - R570)/(R531+R570); as an indication of photosynthetic radiation efficiency; highly correlated with flourescence-based indicator
of Photosystem II light use efficiency & CO2 uptake efficiency (Fv/Fm); PRI values become increasing negative with reduced radiation use efficiency;3)Narrow Band Stress Indices: NDVI695=(R760 - R695)/(R760+R695); NDVI700=(R840 -R700)/(R840+R700); these indices reflect general areas of spectral sensitivity across the range of 450-2500nm and positively correlated with plant health; they are very similar to the Normalized Difference Vegetation Index (NDVI);4) Red-edge Stress Vegetation Index (RVSI) = (R714 + R752)/2 - R733; this index increases with increasing stress at the plant community level and is a simplified approach to characterizing the relative shape of the slope of the chloropphyll red-edge (the sharp rise in leaf reflectance after about 680 nm). After establishment and analysis of full-spectrum leaf reflectance curves and digital images of grape abiotic stress under controlled conditions, a series of experiments will be developed to compare results obtained under greenhouse
conditions with field conditions.
Impacts
Use of remote sensing technology can provide real time information for targeting management inputs within the vineyard; substantially reduce chemical applications while optimizing fruit yield and quality. Thus, providing decreased negative effects on the environment, while enhancing profitability for the producer. This work will test an array of monitoring techniques to enhance the development of stress response detection across the growing season and within vineyards.
Publications
- Silbernagel, J. and Lang, S. 2003. Spatial distribution of environmental stress indicators in Concord grape vineyards. Ecological Indicators 2:271-286.
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Progress 01/01/01 to 12/31/01
Outputs
One of the greatest challenges to the expansion and profitability of horticultural industries is the consistent supply of high quality product. Plant stress (i.e., insufficient/excessive water, nutrient, light, temperature and biotic pressures) is a major limitation to optimizing premium yield and quality. When plant stress symptoms are apparent using conventional crop monitoring methods, a negative impact on crop growth has already occurred. Additionally, plant stress may not be uniformly distributed in a specific location. More specific information on the spatial distribution of stresses can optimize management by focusing inputs where they are needed. Full spectrum leaf reflectance measurements were completed on potato grown at different plant densities and soil calcium levels. Data is currently being analyzed. Experiments will be repeated during the 2002 production season. Additional experiments to evaluate full spectrum leaf reflectance and digital images for
detection of biotic stress on wine grapes will be initiated during the 2002 season.
Impacts
(N/A)
Publications
- No publications reported this period
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