In this study, the effect of vermicompost and mycorrhizal fungi was investigated on growth, yield, chlorophyll pigments, leaf antioxidant enzymes, and seed silibinin content of Silybum marianum, milk thistle. The seeds were inoculated by two species of mycorrhiza fungi, Glomus mosseae and G. intraradices, and plants were irrigated and treated with 0, 25, 50, and 75% vermicompost after culturing...

The Soil Plant Analysis Development (SPAD) chlorophyll meter is one of the most commonly used diagnostic tools to measure crop nitrogen status. However, the measurement method of the meter could significantly affect the accuracy of the final estimation. Thus, this research was undertaken to develop a new methodology to optimize SPAD meter measurements in rice (Oryza sativa L.). A flatbed color ...

The resource availability hypothesis predicts an increase in the allocation to secondary metabolites when carbon gain is improved relative to nutrient availability, which normally occurs during periods of low irradiance. The present work was carried out to confirm this hypothesis by investigating the effects of decreasing irradiance on the production of plant secondary metabolites (flavonoids a...

Leaf-level studies of Metrosideros polymorpha Gaud. (Myrtaceae) canopy trees at both ends of a substrate age gradient in the Hawaiian Islands pointed to differential patterns of adjustment to both nutrient limitation and removal of this limitation by long-term (8-14 years) nitrogen (N), phosphorus (P) and N + P fertilizations. The two study sites were located at the same elevation, had similar ...

-In this study, impacts of vector quantization compression on prediction of leaf chlorophyll content of crops for the application to precision agriculture were evaluated. The compression algorithm tested in this paper is called successive approximation multi-stage vector quantization (SAMVQ). The hyperspectral data used were acquired by CASI over corn fields at L’ Acadie experimental farm (Agri...

The effects of gibberellic acid (GA3) on growth, physiology and yield of salt-stressed mustard (Brassica juncea L. Czern & Coss) cv. Varuna plants were studied. The stress imposed by 25 or 50 mM NaCl reduced substantially leaf area, dry mass, leaf chlorophyll content, stomatal conductance and net photosynthetic rate 50 days after emergence. At harvest, although other yield components were gener...

Crop gross primary productivity (GPP) is an important characteristic for evaluating crop nitrogen content and yield, as well as the carbon exchange. Based on the close relationship observed between GPP and total chlorophyll content in crops, we applied a model that relies on a product of chlorophyll-related vegetation index and incoming photosynthetically active radiation for remote estimation ...

To investigate the physiological responses of sunflower (Helianthus annuus L., Alstar hybrid) to water stress under different levels of zinc fertilizer, an experiment was conducted at the Isfahan Agricultural Research Center, Isfahan, Iran, during 2008 and 2009 using a randomized complete block design within a split plot layout with three replications. Five irrigation treatments used in thi...

Radiative transfer models have seldom been applied for studying heterogeneous grassland canopies. Here, the potential of radiative transfer modeling to predict LAI and leaf and canopy chlorophyll contents in a heterogeneous Mediterranean grassland is investigated. The widely used PROSAIL model was inverted with canopy spectral reflectance measurements by means of a look-up table (LUT). Canopy s...