Based on prior field observations, we hypothesized that individual and interacting effects of plant size, density, insect herbivory, and especially fungal disease, influenced seedling and juvenile plant growth in native Platte thistle populations (Cirsium canescens Nutt.). We worked at Arapaho Prairie in the Nebraska Sandhills (May August 2007), monitoring plant growth, insect damage, and funga...

We hypothesized that a parasitoid of an herbivore would be attracted to large rather than small patches of plants that provide food for the herbivore. We conducted experiments to determine whether such parasitoids would be more likely to find and/or less likely to leave large patches of their victims' host plants. We also examined whether prey density (independent of patch size) affects plant f...

in order to study the effects of sowing date and plant density on forage yield and some morphological characteristics of corn, an experiment was conducted in gorgon research station in 2008. in this experiment two sowing date (18 april and 21 june) and six plant densities (25000, 45000, 65000, 85000, 105000, and 125000 plant per hectare) were evaluated in form of factorial experiment (2×6) with...

The role of density dependence in the population dynamics of tropical trees has been a subject of considerable debate. Here, we present data on the demography of the edible palm Euterpe edulis, classified into seven size categories and monitored over three years. On average, each adult palm contributed 98 seedling recruits per year into the population. The pattern of mortality was similar to th...

in order to study of nitrogen absorb and use efficiency of wheat (triticum aestivum) and wild oat (avena fatua) at vegetative growth stage, a factorial experiment was conducted based on completely randomized block design with three replications in research greenhouse of faculty of agriculture, at ferdowsi university of mashhad in 2008. the first factor was competition between wild oat (densitie...

cultivation of annual medics is a way to increase producing of forage with a better quality, to increase the quantity of producing forage in low yield drylands, and to assisst establishing pasture. this study was conducted in order to investigate the adaptation and determination of quantitative and qualitative characteristics of three species of annual medics. the experimnet was conducted in a ...