this study assessed the optimum water need of pepper (capsicum annuum l. cv. california wonder) and the critical irrigation level to be applied in order to achieve a reasonable economic yield in water shortage conditions. in a controlled field experiment involving five different treatments, seasonal evapotranspiration for pepper fluctuated from 89 mm in the severe stress treatment (i0.00) to 1,...

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...

Understanding processes of maize (Zea mays L.) growth and production of grain in highyielding, irrigated conditions offers hope to understand yield potential in many other environments. In this study we investigated such processes at the plant level, and attempted to simulate maize yields at the field level and county level in the high yielding region of the High Plains of Texas. In addition, w...

in order to evaluate the effects of sugar beet sowing date, planting density and cultivar on solar radiation interception, the present study was conducted in kamal-abad agricultural research station of sugar beet seed institute (sbsi) in 2005 and 2006. the experiment arranged was in split-split plots based on randomized complete block design (rcbd) with three replications. the sowing date, plan...

Background Under field conditions, the development of crops depends on capacity of the canopy to intercept incident radiation and convert it into new biomass (Gifford et al. 1984). The amount of incident radiation intercepted depends on the leaf area index (LAI) and canopy orientation in space. The fraction of the incident photosynthetically active radiation (IPAR) that is absorbed by a canopy ...

and Amthor (1999) suggested that the RUE era in crop modeling should be closed. Accurate measurement of crop growth and radiation use efficiency A number of factors contribute to the variation in (RUE) under optimal growth conditions is required to predict plant reported estimates of RUE (Sinclair and Muchow, 1999). dry matter accumulation and grain yield near the genetic growth potential. Rese...

ABSTP, ACT. Growth data from the most recent 5 years of a 40-year thinning study in an even-aged red pine (Pinus resinosa) forest in Cutfoot Sioux Experimental Forest, Minnesota, were used with intercepted photosynthetically active radiation (IPAR) data to determine the relationship between light interception and growth for a range of stand densities. Stand basal area (BA) growth was proportion...

The crop intercepted photosynthetically active radiation (PAR) and radiation use efficiency (RUE) vary markedly in different intercropping systems. The HHLA (horizontally homogeneous leaf area) and ERCRT (extended row crop radiation transmission) models have been established to calculate the intercepted PAR for intercrops. However, there is still a lack of study on the intercepted PAR and RUE u...

We present the formulation, calibration and validation of a model to estimate photosynthetically active radiation (PAR) intercepted by olive (Olea europaea L.) canopies. The model calculates the PAR transmittance at any point located within the four central trees of the orchard. The spatial and time integration of this process allows calculation of PAR transmitted to the ground and, thus, the P...

Estimates of carbon uptake at the continental scale become urgently needed as the role of countries as net sinks or sources of carbon gains political and economic importance. Despite uncertainties related to radiation use efficiency, the amount of photosynthetically active radiation (PAR) intercepted by the canopy is a reliable estimator of primary production. Theoretical and empirical data sup...