this experiment was conducted in safi abad agricultural research center of dezful in order to study the effect of seed deterioration and plant density on germination, seedling establishment, yield and yield components of hull-less barley with in 2011- 2012. treatments included three levels of seed deterioration: (control, 72 and 96 hours) and five plant densities (100, 150, 200, 250 and 300 pla...

in order to evaluate effects of plant density and planting date on quality properties of grass pea (lathyrus sativus l.), a factorial experiment was conducted during 2008, based on complete randomized block design with four replications in research farm of faculty of agriculture, the university of birjand, birjand, iran. plants were planted at march 5 and 20, and apr 3, with 30, 40, 50 and 60 p...

In response to food limitation, many insects have evolved developmental plasticity in which larvaematureat a smallerbody size.Herewe investigate theconsequencesof this smallerbody size for development of individuals in the next generation, after resource competition has been relaxed. Families of the seed beetle Stator pruininus (Horn) reared at high density ('20 eggs per seed) matured at a subs...

A mathematical model is presented to estimate the effects of phytochemicals on seed germination. According to the model, phytochemicals tend to prevent germination at low seed densities. The model predicts that at high seed densities they may increase the probability of seed germination and the number of germinating seeds. Hence, the effects are reminiscent of the density-dependent effects of a...

Wood density is an important trait in trees indicative of their life history and mechanical and physiological strategies. The following examines the evolutionary ecology of wood density using a large database for seed plants. In particular, we focused on the geographic and phylogenetic variation in wood density for both gymnosperms and angiosperms. A phylogenetic supertree was constructed for o...

A globally-averaged, pulsed inductive plasma model is reproduced and utilized to investigate pre-ionization conditions for a pulsed inductive plasma accelerator. Attention is given to better quantifying the formation and energy conversion/loss processes associated with the pre-ionization stage. Simulations are completed for different power input pulse duration, seed plasma density, and total in...

Arable land weed seed banks are dynamic and reflect cropping history, current management, and environment. Changes in crop rotation and tillage system can alter weed seed density and species composition. In the semi-arid region of the Pacific Northwest, USA, no-till spring cropping is being studied as an alternative to the traditional winter wheat (Triticum aestivum L.)/dust-mulch fallow (WWF) ...

A digital image of a plant seed can be regarded as a two-dimensional object which can be measured in size, shape and color density during the development stage of germination by computer image analysis technology. Seed changes its biological structure passing from a quiescent stage to a proliferating one, and any morphological variation can be associated with the corresponding variation of seed...