abstract the effect of different larval density of chilo suppressalis walker was evaluated through 2006-2008 on rice infestation in controlled condition of the cages. the results indicated that there were significant effects between dead hearts, white heads and crop yield. the highest dead hearts and white heads were related to the treatment of 32 larvae per m2 and the lowest ones were obtained...

â  the purpose of this study is investigation of relationship between population dispersion and distribution of services in urban area of yazd city. descriptive-analytic methodology was used in this study according to physical devising housing and urbanization organization. yazd city is comprised of 11urban areas, with areas of 13415 (ha) and 447259 population spatial distribution of population...

objective: taro (colocasia esculenta l. 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 effect...

spiders are the powerful and efficient predators in almost all ecosystems which have effective role in different pest control. the fauna of these arthropods was surveyed during 2005-2009, and their population fluctuations and activities were studied in mazandaran paddy fields in 2005-2006. a total of 53 spider species of 44 genera were collected and identified from paddy fields of mazandaran pr...

bionomics of aphis gossypii glover and its predators coccinella septempunctata l. and hippodamia variegata goeze were studied in varamin (tehran province) during 11th may to 5th october 2006 on eggplant crop, with the interaction (density dependence) between the aphid and either of the predators determined. the reliable sample size (number of leaves) with a maximum variation of 6.73% was about ...