نتایج جستجو برای: and population density

تعداد نتایج: 16946265  

2017
Thomas. J. McAvoy Jacques Régnière Rémi St-Amant Noel F. Schneeberger Scott M. Salom

Eastern (Tsuga canadensis) and Carolina hemlocks (T. caroliniana) of eastern North America have been attacked by the non-native hemlock woolly adelgid (Adelges tsugae Annand) (HWA) since the first half of the 20th century. Unlike most insects, HWA develops through one generation from fall to late winter, exposing this insect to the lethal effects of winter temperatures. The mortality inflicted ...

2017
Francois Spitz FRANCOIS SPITZ

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...

Journal: :پژوهش های حبوبات ایران 0
روشنک قربانی سیدکریم موسوی محسن غیاثوند جواد کریم زاده اصفهانی

the effects of sowing date and crop density of chickpea on population and infestation of pod borers were studied in a randomized complete block design by factorial arrangement with three replications in the chickpea growing region of greet, khorramabad in 2007 until 2009. experimental factors comprised of sowing dates (march 14, march 30, and april 21) and crop density (25, 50 and 75 plant.m-2)...

Journal: :The American naturalist 2013
Martin M Turcotte David N Reznick J Daniel Hare

An eco-evolutionary feedback loop is defined as the reciprocal impacts of ecology on evolutionary dynamics and evolution on ecological dynamics on contemporary timescales. We experimentally tested for an eco-evolutionary feedback loop in the green peach aphid, Myzus persicae, by manipulating initial densities and evolution. We found strong evidence that initial aphid density alters the rate and...

طبری, مهرداد, علی نیا, فرامرز, قهاری, حسن,

  Striped rice stem borer, Chilo suppressalis Walker (Lepidoptera: Pyralidae) is one of the key pests in north of Iran, which damages the rice fields and decreases yield, severely. With attention to the importance of population dynamics of pests in integrated pest management, the population dynamics of immature life stages (egg, larva, pupa) of C. suppressalis were analyzed on three dominant ri...

پایان نامه :0 1374

in fact, this study focused on the following questions: 1. is there any difference between the effect of functional/notional approach and the structural approaches to language teaching on the proficiency test of efl learners? 2. can a rather innovative language test referred to as "functional test" ge devised so so to measure the proficiency test of efl learners, and thus be as much reliable an...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه الزهراء - دانشکده علوم تربیتی و روانشناسی 1391

abstract: research purpose: the purpose of this research is to identify academic databases assessment factors and criteria at law and political science majors. the necessity of this research is to distinguish academic databases assessment factors and criteria and to identify the most important ones and rank them in order to select an appropriate database according to students’ and faculty memb...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان 1389

run-out-table (rot) is located between last finishing stand and down coiler in a hot strip mill. as the hot steel strip passes from rot, water jets impact on it from top and bottom and strip temperature decreases approximately from 800-950 °c to 500-750°c. the temperature history that strip experience while passing through rot affects significantly the metallurgical and mechanical properties, s...

Journal: :international journal of advanced biological and biomedical research 2015
ashenafi nigussie belisty lule aynalem gebre

a field experiment was conducted at wondo genet agriculture research center under irrigated condition to determine the effect of intra and inter-row spacing on growth and yield of artemisia (artemisia annua l.) during the two successive seasons of 2013 and 2014. factorial combinations of four intra-rows (40, 60, 80, 100 cm) and four inter-row plant spacing’s (60, 80, 100, 120 cm) were laid out ...

Journal: :international journal of advanced biological and biomedical research 2015
aynalem gebre bizuayehu tesfaye beemnet mengesha kassahun

taro (colocasiaesculental. schott) is a perennial root crop that belongs to araceace family. it is widely cultivated as a staple food in africa, asia and pacific islands. despite its importance, there is limited information on many aspects of the crop. in order to obtain data that can support improved and sustainable taro production, a field trial was conducted to study the effects of corm size...

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