in order to study the effect of plant density on yield and agronomic traits on new sunflower varieties in esfahan condition, an experiment was conducted in 2009 cropping season at agricultural research institute kabotar abads. the experimental design was factorial in a randomized complete block design with four replications. the experimental treatments were at 4 levels of plant density (6,8,10 ...

high nitrogen and plant density cause increasing vegetative growth and reducing harvest index. the objective of this study was to evaluate the effect of cycocel at high nitrogen and plant density on safflower yield and yield components. for this purpose a field experiment was carried out as a factorial-split plot based on randomized complete block design with three replications with esfahan 14 ...

Janzen-Connell effects are negative effects on the survival of a plant's progeny at high conspecific densities or close to its conspecifics. Although the role of Janzen-Connell effects on the maintenance of plant diversity was frequently studied, only few studies targeted Janzen-Connell effects via postdispersal seed predation in temperate grassland systems. We examined effects of conspecific d...

the effects of plant densities (25, 35 and 45 plants m-2 as d1, d2 and d3 respectively), and inoculation with rhizobium bacteria (without rhizobium, with rhizobium and rhizobium + microelement application), on growth and yield were studied in chickpea (cicer arietinum l.). experiment was carried out in 2008 at research farm of the faculty of agriculture of university of mohaghegh ardabil, a fac...

1. Genotypic diversity in plant populations is known to enhance plant performance and ecosystem function. Nonetheless, the effect of genotypic diversity has rarely been examined across a population’s lifecycle despite the expectation that changing conditions, such as population density, will alter the benefits of diversity. 2. We simultaneously manipulated a component of genotypic diversity (ri...

In order to upgrade the local method of processing the seed it is necessary to collate basic data on physical, mechanical and chemical properties of the seed and pod as evaluated using standard methods. The length, breadth and thickness of the pods were 12.29 mm, 8.28 mm and 4.44 mm respectively while that of seed were 4.36 mm, 3.46 mm and 1.37 mm respectively. Seed weight, bulk density, true d...

to evaluate the effects of planting date and plant density on morphological characteristics, including essential oil content of ajowan (trachyspermum ammi) a study was conducted during the years 2003 and 2004 at the experimental farm, faculty of agriculture, ferdowsi university of mashhad. treatments were laid out in a factorial form based on a complete randomized block design of three replicat...

We investigated seed dispersal and density-dependence of seed, seedling and sapling survival in two BCI tree species of contrasting life history strategies, using data from seed traps, soil seed samples, seedling plots within the forest dynamics plot, and the plot census data themselves. Seed dispersal distances and seed production per unit basal area were significantly higher in Miconia argent...

The high quality and quantity seed production in old saxual shrubs are essential for regeneration and sustainable development of saxual forests in desert areas. The objective of this study was to determine the effects of different pruning height on saxual seed production. The study was carried out in an obviously wilted saxual forest located in Ashkezar desert in Yazd in 1994. The experiment wa...

Plant-animal interactions imply costs and benefits with net balance depending on interacting species and ecological context. Ungulates, in particular, confer costs (e.g., plant leaf consumption, flower bud predation) and benefits (e.g., plant overcompensation, seed dispersal) to plants. Magnitude of costs and benefits may be altered by habitat management or ecological conditions favoring high d...