Purpose of Review This review shows that a more or less constant rate of tip-to-base vessel widening across species, together with the assumption that wider vessels are more vulnerable to embolism, suggests how climate should limit maximum vegetation height; together, these two factors predict a maximummean vessel diameter permitted by temperature and water availability at a site and thus maxim...

A field experiment was conducted in 2010, to evaluate the effects of plant density (D1, D2 and D3: 8, 14 and 20 plant/m2) on field performance of Sorghum under different nitrogen application rates (N1, N2 and N3: application of 40, 80 and 120 kg/ha Nitrogen, respectively). The experiment was arranged as factorial based...

the effect of different ratio of vermicompost (0, 10, 20, 30, 40 & 50 %) in two type of substrate (coco peat and coco peat-perlite (50:50 v:v)) on growth characteristics of gooseberry (physalis peruviana l.) seedling was investigated in research greenhouse of university of tehran, in 2013. a factorial experiment based on completely randomized design with four replications was carried out. crite...

the water deficiency is one of the serious problems in the arid zones. in order to investigate the effect of cycocel on different growth aspects of two olive cultivars (mary and mission), a greenhouse experiment was conducted using three factors of: cycocel at three levels (0, 500 and 1000 mg l-1), irrigation of three levels (irrigated at 5, 10 and 15 days intervals) and tow olive cultivars (ma...

Temperature changes occur in nature faster than other stressors. Plants due to inability to move and change their position, are exposed to extensive variations in daily or seasonal temperature, and therefore, should quickly and effectively adapt to temperature stress. In order to study the effects of heat stress on physiological traits of forage maize hybrids, a factorial split plot experiment ...

today, environmental crisis and loss of natural resources are the principle causes of the creation of environmental management systems. the optimal management of natural resources requires the assessment and classification of ecological and environmental potentials. using this method, the abilities and restrictions of resources can be recognized, and their future trends can be predicted. nebka ...

a split plot experiment based on randomized complete block design (rcbd) with three replications was conducted in 2012,treatments were included the time of foliar application with 3 levels (tillering stage, heading stage and no spray (control)) as main factor and cultivars in 4 levels (sardari, rijav, biseton and rashid) as the second factor. plant characteristics such as plant height, length o...

A field experiment was conducted in 2010, to evaluate the effects of plant density (D1, D2 and D3: 8, 14 and 20 plant/m2) on field performance of Sorghum under different nitrogen application rates (N1, N2 and N3: application of 40, 80 and 120 kg/ha Nitrogen, respectively). The experiment was arranged as factorial based...

study of soil and plant relationships is nessesery for ecological- based and appropriate management. the objective of this study is to determine the influence of edaphic properties on haloxylon persicum growth and also, indentifing growth limiting soil properties for saxaul. the study was performed through the stratified random sampling and 3 sites were selected as follow: planted strong saxaul...

fire, as a natural ecological disturbance factor in forest, this study located in the marivan region, northern zagros forest, and western iranian state of kurdistan. in each burned and unburned area 30 circle sample plot (1000 m2) were collected by randomized–systematic method in the 100×200 m net (in total 60 plots). in every sample plot the kind of species, number of tree, the height of coppi...