in order to study of the radiation interception and red to far red light ratio variations in sunflower hybrids under drought stress, nine sunflower hybrids in three separate experiments were compared as randomized complete block designs with three replications at the research station of seed and plant improvement institute in karaj in 2006. first experiment (control) was irrigated based on 60 m...

in order to study of some effective phenologic and physiologic characteristics on 18 sunflower hybrids yield under optimum conditions, an experiment was conducted as randomized complete block design with three replications at the research field of seed and plant improvement institute-karaj in 2006-2007. the result indicated that the hybrids showed significant difference in phonologic characteri...

Identifying the characteristics of light interception and utilization is of great significance for improving the potential photosynthetic activity of plants. The present research investigates the differences in absorbing and converting photosynthetically active radiation (PAR) among various cotton cultivars. Field experiments were conducted in 2012, 2013 and 2014 in Anyang, Henan, China. Ten cu...

intercropping may be helpful manner to increase interception and utilization. the aim of this study was to compare radiation use efficiency and radiation interception in intercropping with sole cropping. an experiment was conducted at the agricultural research station, ferdowsi university of mashhad in the growing season of the year 2008. the experimental treatments were: 1- sole crop of bean 2...

A small set of independent variables generally seems to suffice when attempting to describe the spectral response of a vegetation canopy to incident solar radiation. This set includes the soil reflectance, the single-scattering albedo, canopy transmittance, reflectance and interception, the portion of uncollided radiation in the total incident radiation, and portions of collided canopy transmit...

Interception of photosynthetically active radiation (PAR) was evaluated relative to greenness and normalized difference [MSS (7 5)/(7 + 5)] for five planting dates of wheat for 1978-79 and 1979-80 at Phoenix, Arizona. Intercepted PAR was calculated from leaf area index and stage of growth. Linear relationships were found with greenness and normalized difference with separate relationships descr...

Most agronomic models estimate canopy light interception using the Beer-Lambert law. This method only accounts for leaf area index (LAI) and leaf angle distribution (LAD) without considering the crop’s structural heterogeneity in space, or soil-leaf or leaf-leaf radiative scattering. These factors have been extensively studied during the past ten years e.g; (Luquet et al. 1998; Nouvellon et al....

The amount of photosynthetically active radiation (PAR) absorbed by a canopy (APAR) is an important driving variable for vegetation processes such as photosynthesis. PAR extinction in clumped canopies of shortgrass ecosystems is the focus of this paper. Directional gap fractions estimated at peak biomass on several Mexican shortgrass ecosystems with a hemispherical radiation sensor (Li-Cor, LAI...