In comparison to deciduous species, evergreen plants have lower leaf nutrient contents and higher leaf life span, important mechanisms for nutrient economy, allowing the colonization of low fertility soils. Strategies to conserve nitrogen in two semideciduous tropical forest tree species, with different leaf life spans were analyzed. The hypothesis was the fact that the two species would presen...

Leaf characteristics of mature 2, 3 and 4-year-old North American ginseng (Panax quinquefolius L.) leaves on fruiting and non-fruiting (NF) plants were studied. Leaflets of the 2-year-old plants had the lowest fresh and dry weight, area, volume and internal gas volume. Inflorescence removal in 3-year-old plants did not affect leaf characteristics or ginsenoside concentration but in 4-yearold pl...

The effects of leaf toughness, trichome characteristics, nutrient and water availability, and secondary chemistry on diet selection by the leafcutting ant Atta cephalotes were determined using individuals of 49 woody plant species from a tropical deciduous forest in Costa Rica. The palatability of plants was measured by presenting whole leaves to leafcutting ant foragers on trails and counting ...

This study evaluated the basic dosimetric characteristics of a Dynamic Multi Leaf Collimator (DMLC) using a diode detector and film measurements for Intensity Modulated Radiation Therapy Quality Assurance (IMRT QA). The EGSnrc Monte Carlo (MC) simulation system was used for the determination of MLC characteristics. Radiation transmission and abutting leaf leakage relevant to the LinaTech DMLC H...

abstract silicon (si) is considered one of the beneficial elements for plant, however recent studies show that si plays an important role in plant resistance to environmental stresses , like salinity. an experiment was conducted to study the effect of si and nacl salinity on the growth, yield and fruit quality of strawberry (fragaria × ananassa duch) cv “selva” was grown hydroponically in the c...

background and objectives:  hawthorn is a forest fruit tree which is grown in the temperate regions around the world. this plant is known as the most traditional herbal remedy for heart failure and cardiovascular disease in worldwide. this study has been conducted to investigate the genetic variability and classify hawthorn genotypes based on quantitative and qualitative characteristics of leaf...

Leaf senescence varies greatly among cotton cultivars, possibly due to their root characteristics, particularly the root-sourced cytokinins and abscisic acid (ABA). Early-senescence (K1) and late-senescence (K2) lines, were reciprocally or self-grafted to examine the effects of rootstock on leaf senescence and endogenous hormones in both leaves and xylem sap. The results indicate that the graft...

in order to determine the effects of zinc foliar application on the vegetative characteristics, yield and fruit quality in strawberry (fragaria × ananassa duch) cv kordestan under salinity stress conditions, an experiment was carried out hydroponically in glasshouse as a controlled environment during 2009 through 2010. three levels of nacl (0, 15, 30 mm) and three levels of zn (0, 1.5, 3 g/l) w...

Crop models need accurate simulation of the interdependent processes of crop development and leaf area production. Crop development proceeds according to genotype characteristics and environmental influences, specifically temperature and photoperiod. It can be partly described by thermal requirements for development intervals and coefficients that describe genotype adaptation. The objectives of...