Analyzing variation in plant canopy conversion efficiency and assessing canopy and leaf photosynthetic efficiency in soybean with reduced chlorophyll content
type: CreativeWork
description: The conversion efficiency of absorbed radiation into biomass (εc) is a component of yield potential. Unlike other efficiency components of yield potential, εc in C3 and C4 plant groups is estimated to be much lower than the theoretical maxima, signifying that εc limits yield potential but has room for improvement. This makes it the ideal candidate to increase yields to meet the food and fuel demand of the world population. Understanding the causes of variability in εc are important when considering new approaches to improving εc. Therefore, the first part of this research focused on using past literature to quantify environmental and managerial effects on εc and assess the variability in εc between and within major food and biofuel crops. The second part of this research tested the hypothesis that reduced chlorophyll content would increase εc at both the canopy and leaf level using field and microscopy techniques. In chapter one, a meta-analysis was used to statistically quantify the effects of greenhouse gases, weather-related stresses projected to intensify due to climate change, and management practices on εc from 140 published studies. Significant increases in εc were caused by elevated [CO2], shade, and intercropping, whereas εc was reduced by elevated [O3], water stress, temperature stress, and foliar damage. εc curvilinearly increased with nitrogen and phosphorus applications. These findings suggest that extensive variability is present in εc with external factors, and improved management, breeding for greater stress tolerance, and selecting for enhanced responses to positively contributing factors will increase εc and therefore yields and yield potential. In chapter two, past literature was analyzed to determine current statuses and trends in εc across unstressed food and biofuel crops. Data was mined from 153 studies that measured εc in six important food crops (maize, sorghum, rice, wheat, barley, peanut, soybean, chickpea, pigeonpea) that spanned major fu…
abstract: The conversion efficiency of absorbed radiation into biomass (εc) is a component of yield potential. Unlike other efficiency components of yield potential, εc in C3 and C4 plant groups is estimated to be much lower than the theoretical maxima, signifying that εc limits yield potential but has room for improvement. This makes it the ideal candidate to increase yields to meet the food and fuel demand of the world population. Understanding the causes of variability in εc are important when considering new approaches to improving εc. Therefore, the first part of this research focused on using past literature to quantify environmental and managerial effects on εc and assess the variability in εc between and within major food and biofuel crops. The second part of this research tested the hypothesis that reduced chlorophyll content would increase εc at both the canopy and leaf level using field and microscopy techniques. In chapter one, a meta-analysis was used to statistically quantify the effects of greenhouse gases, weather-related stresses projected to intensify due to climate change, and management practices on εc from 140 published studies. Significant increases in εc were caused by elevated [CO2], shade, and intercropping, whereas εc was reduced by elevated [O3], water stress, temperature stress, and foliar damage. εc curvilinearly increased with nitrogen and phosphorus applications. These findings suggest that extensive variability is present in εc with external factors, and improved management, breeding for greater stress tolerance, and selecting for enhanced responses to positively contributing factors will increase εc and therefore yields and yield potential. In chapter two, past literature was analyzed to determine current statuses and trends in εc across unstressed food and biofuel crops. Data was mined from 153 studies that measured εc in six important food crops (maize, sorghum, rice, wheat, barley, peanut, soybean, chickpea, pigeonpea) that spanned major fu…
author: Slattery, Rebecca
language: en
keywords: photosynthesis, photosynthetic efficiency, energy conversion efficiency, chlorophyll, food security
date published: 2014-09-16T17:23:15Z
date modified: 2026-07-22T22:25:40Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/50511