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 ...

Forecasting the damages by voles on plant crops depends on a good forecast of vole population density. Biological work in Vendee from 1959 till 1968 have furnished the fundamentals of a population model. Further work on the relationship between breeding and climate enabled us to set up a practical forecasting model. This is applied by the Plant Protection Service, and the damage prevention syst...

Mathematical models serve many purposes in biology. Each and every model is a necessary simplification of reality, and, as simplifications, these are also wrong by definition. And yet there ways to be wrong, some much greater concern than others. For example, paradoxical model-based prediction may simply puzzling whereas unphysical variables (e.g. negative amounts time or temperatures below abs...

in order to survey the influence of metribuzin herbicide on physiological indices and yield of wheat, an experiment was conducted at experimental field of plant pest and disease research institute, karaj, iran during 2007. treatments were in factorial arrangement laid out in four randomized complete blocks. the factors investigated were three plant densities: 400, 500 and 600 plant.m-2 and metr...

in order to determine radiation use efficiency and phenological and physiological characteristics of three maize hybrids on seven plant densities, an experiment was conducted during 2006 growing season in mashhad, iran. three maize hybrids including late-rippening maize (704), medium-rippening (504) and early-rippening maize (260) and seven plant densities including d1=3, d2=5, d3=7, d4=9, d5=1...

this experiment was carried out to investigate the effect of plant density on growth and seed yield of wheat (kodasht cultivar) under saline soils and rainfed condition inanbarolum region of golestan province in 2008-09. an experiment was conducted in three fields with different salinities (6.73, 9.34 and 11.63 ds m-1) based on randomized complete blocks design. treatments were four plant densi...