distribution and stability of purple nutsedge (cyperus rotundus) population within four fields under corn-fallow rotation were analyzed over two growing seasons in 2005 and 2006 at the agricultural research station of ferdowsi university, mashhad, iran. in 2005, n-fertilizer (urea) was applied at two different application methods (whole and split application). as a result of applying or not app...

the two-spotted spider mite, tetranychus urticae koch (acari: tetranychidae), is an economically important pest of ornamental plant in iran. the population abundance and spatial distribution were studied on five rosa cultivars including maroussia, wendela, elderado, wenedetta, and hot lady during two growing seasons of 2011 and 2012 in greenhouse. the k parameter, index of dispersion, lloyd’s m...

better understanding and recognizing the amount of cultural development in iranian provinces and comparing them, causes a particular attention and helps to recognize their weaknesses, strengths, potentialities and deficiencies. the purpose of this paper is to analyze cultural development indicators in iran. the writers of this article present an applied research and use a comparative method. us...

sustainable management of limited land and water resources is urgently needed to meet the increasing demand for food and to protect the environment. land suitability analysis is a prerequisite in assessing and proposing sustainable land use alternatives for an area. soil data are usually available at different levels of detail and stored in various forms, usually soil maps and/or soil observati...

the present study was carried out to evaluate three interpolation methods including weighted moving average (wma) with the power of 2 and 3, kriging and cokriging methods. data of 23 wells in mazandaran province were collected in fall and spring 2006. seven parameters including electrical conductivity (ec), ph, total dissolved solids (tds), sodium adsorption ratio (sar), total hardness (th), ch...

background: national institute of environmental health sciences (niehs) scientists shows that long-term exposure to air pollutants increases the risk of respiratory diseases such as allergies, asthma, chronic obstructive pulmonary disease, and lung cancer. children and the elderly are particularly vulnerable to the health effects of ozone, fine particles, and other airborne toxicants. air pollu...

today, with the advanced statistical techniques and neural networks, predictive models of distribution have been rapidly developed in ecology. purpose of this research is to predict and map the distribution of tetranychus urticae koch (acari: tetranychidae) using mlp neural networks combined with genetic algorithm in surface of farm. population data of pest was obtained in 2016 by sampling in 1...

the seasonal abundance patterns of the cotton aphid, aphis gossypii glover, in cotton fields at gorgan in northern iran were studied during two growing seasons of 2002 and 2003. the spatial distribution of different developmental stages and morphs of the aphid was described by fitting data to poisson (random) and negative binomial (aggregated) dis-tributions, and calculating the dispersion indi...