abstractbackground and objectives: black mustard (brassica nigra (l.) koch) is an annual plant belongs brassicaceae. it has a variety of uses in traditional medicine for rheumatic and neurological pain. growth and development and production of medicinal plants, like other plants is influenced by genetic and environmental factors. select the most appropriate planting date and the most favorable ...

Studies on the importance of seed arrival for community richness and composition have not considered the number of seeds arriving and its effect on species richness and composition of natural communities is thus unknown. A series of experimental dry grassland communities were established. All communities were composed of the same 44 species in exactly the same proportions on two substrates usin...

The life histories of many species depend first on dispersal to local sites and then on establishment. After dispersal, density-independent and density-dependent mortalities modify propagule supply, determining the number of individuals that establish. Because multiple factors influence recruitment, the dichotomy of propagule versus establishment limitation is best viewed as a continuum along w...

adjustment of plant density is an important base on light, water and soil nutrients for increasing seed yield. to determine of plant density in new red bean lines (phaseolus vulgaris l.), this experiment was conducted as factorial in randomized complete block design (rcbd) with three replications at lordegan region (chaharmahal and bakhtiari province) in 2004-2005. factors were new red bean lin...

to study the effect of plant density on seed yield and yield components of two lentil cultivars a field experiment using factorial design based on a complete block design was conducted with three replications at research farm of college of agriculture and natural resources, university of tehran (karaj) in 2008. treatments were lentil varieties (ziba, mardom), and plant densities (80, 160, 240, ...

Immigration rates of species into communities are widely understood to influence community diversity, which in turn is widely expected to influence the susceptibility of ecosystems to species invasion. For a given community, however, immigration processes may impact diversity by means of two separable components: the number of species represented in seed inputs and the density of seed per speci...

in order to study on effect of plant density and nitrogen on yield and yield components of visia faba (faba bean), the experimental design was implemented by randomized complete block with three replications at 2010- 2011 in lahijan. the experimental factors were three plant density (25×25 cm, 35×35 cm and 45×45 cm) and four nitrogen fertilizer (0, 20, 40, 60 kg ha-1). in this experiment, featu...

abstract persian shallot (moseer) belongs to alliaceae family, is a perennial medicinal and industrial edible alliums in iran. very little information is available about different aspects of this species particularly on its agronomical production. in order to determine optimum sowing date and plant density in persian shallot, an experiment was conducted as split plot based on complete randomize...

Seed banks play a crucial role in arid plant communities because they confer stability and longterm persistence. However, seed banks have high temporal and spatial variability, with dramatic changes in density and composition. The aim of this study was to test whether seasonal change affected seed bank community structure and spatial pattern. Moreover, we wanted to know if the effect driven by ...

—In desert environments seeds are often heterogeneously distributed in small patches that vary in number of seed species and in seed density. Because seed harvest by rodents is often density dependent (a larger proportion of seeds is removed from high-density seed patches than from low-density patches), the proportion of residual or post-harvest seeds should be greater in low-density patches. I...