Shade and sun leaves of Valencia orange [Citrus sinensis (L.) Osbeck] were collected to evaluate comparative effects of their leaf chlorophyll concentration, water content, thickness, and mesophyll volume of air on visible light reflectance, specifically the 0.45-, 0.55-, and 0.65-#m wavelength (WLs). The reflectance at the 0.45-, 0.55-, and 0.65-/~m WLs of sun leaves but not shade leaves was n...

In a 3-year experiment (2002-2004), five N rates (0, 60, 120, 180, 240 kg N ha-1) were applied to sugar beets arranged in a Randomized Complete Block design with six replications. Experimentation took place under the semi-arid, irrigated conditions of central Greece. The aim of this work was to study the late season response of sugar beet crop to N fertilization as assessed by non-destructive m...

A trial for estimating leaf chlorophyll content based on leaf reflectance was conducted for three major plant species in Daegu, South Korea. To estimate the chlorophyll content in a leaf, we measured the leaf elongation and related the leaf reflectance to its absorbance. Leaves of the target species were found to start elongating around the middle of April and continued elongation until the mid...

Sorghum [Sorghum bicolor (L.) Moench] grain yield is severely affected by abiotic and biotic stresses during post-flowering stages, which has been aggravated by climate change. New parental lines having genes for various biotic and abiotic stress tolerances have the potential to mitigate this negative effect. Field studies were conducted under irrigated and dryland conditions with 128 exotic ge...

Fifty-three leaves were randomly sampled on different deciduous tree species, representing a wide range of chlorophyll contents, tree ages, and leaf structural features. Their reflectance was measured between 400 and 800 nm with a 1-nm step, and their chlorophyll content determined by extraction. A larger simulated database (11,583 spectra) was built using the PROSPECT model, in order to test, ...

Correlations between extractable leaf chlorophyll (Chl) concentration and portable, nondestructive leaf “greenness” meter readings imply that such estimates can be used as surrogate measurements of leaf nitrogen (N) status. However, few studies have actually found a direct relationship between Chl meter readings and leaf N. We evaluated the utility of two handheld transmittance-based Chl conten...

The effects of potassium fertilizer (K2SO4) levels K0, (0), K1,(150) and K2,(250 kg/ha) in two species of Brassica napus (Hyola 401 Hybrid) and Brassica juncea (landrace cultivar), under three irrigation regimes, control (irrigation after 50%,), moderate stress, (irrigation after 70%), and severe stress (irrigation after 90% soil water depletion) were studied in a factorial experiment laid out ...

Grafting is a technique that may affect plant tolerance to iron chlorosis in plants cultivated for their fruit. Therefore, the objective of this study was to evaluate the tolerance of non-grafted quince seedlings and pear grafted onto quince plants cultivated in pots with alkaline soil. The experiment was conducted in a greenhouse at the University of Cordoba, Spain, in pots (3 L) filled with a...

Local haplotype patterns surrounding densely spaced DNA markers with significant trait associations can reveal information on selective sweeps and genome diversity associated with important crop traits. Relationships between haplotype and phenotype diversity, coupled with analysis of gene content in conserved haplotype blocks, can provide insight into coselection for nonrelated traits. We perfo...