in order to evaluate plant density and different nitrogen levels on protein percent, yield and nitrate accumulation in potato tuber cv. agria, a factorial experiment based on randomized complete block design with three replications was conducted in ardabil in 2006. factors included nitrogen levels: 0, 80, 160 and 200 kg ha-1 net nitrogen and plant densities: 5.5, 7.5 and 11 plant m-2. results s...

The beet armyworm, Spodoptera exigua, is one of the most important pests of sugar beet in Iran. The aim of this study was to determine the effect of water and nitrogen treatments of sugar beet planton developmental time and fecundity life table parameters of the pest. An experiment was carried out under laboratory conditions (25±2oC, 70±5% R.H. and 12L: 12D) on larvae reared...

The beet armyworm, Spodoptera exigua, is one of the most important pests of sugar beet in Iran. The aim of this study was to determine the effect of water and nitrogen treatments of sugar beet planton developmental time and fecundity life table parameters of the pest. An experiment was carried out under laboratory conditions (25±2oC, 70±5% R.H. and 12L: 12D) on larvae reared...

The beet armyworm, Spodoptera exigua, is one of the most important pests of sugar beet in Iran. The aim of this study was to determine the effect of water and nitrogen treatments of sugar beet planton developmental time and fecundity life table parameters of the pest. An experiment was carried out under laboratory conditions (25±2oC, 70±5% R.H. and 12L: 12D) on larvae reared...

Leaf area index (LAI), leaf area duration (LAD), crop growth rate (CGR), net assimilation rate (NAR) and above ground dry matter accumulation (AGDM) of a cultivar of chickpea (Cicer arietenum) were studied with the application of potassium naphthenate (KNap) and naphthalene acetic acid (NAA) as foliar spray in 2001-2002. The growth regulators had greater influence on plants which showed compara...

Costs of plant defense are a key assumption in evolutionary ecology, yet their detection has remained challenging. Here we introduce a novel method for quantifying plant growth using the common milkweed Asclepias syriaca and repeated non-destructive size measurements to experimentally test for costs of defensive traits. We estimated mechanistic components of plant growth (relative growth rate, ...

Whole-plant and leaf nitrogen isotope composition are determined by the isotope ratio of the external nitrogen source and physiological mechanisms within the plant. Whole-plant isotope composition can reflect that of the nitrogen source when plant demand exceeds nitrogen supply. Uptake by mycorrhizae can cause the isotope ratio of the plant to deviate from the source. Intra-plant variation in i...

The long-term efficacy of stormwater treatment systems requires continuous pollutant removal without substantial re-release. Hence, the division of incoming pollutants between temporary and permanent removal pathways is fundamental. This is pertinent to nitrogen, a critical water body pollutant, which on a broad level may be assimilated by plants or microbes and temporarily stored, or transform...

Seed mass and relative growth rate (RGR) are important determinants of early seedling growth, and hence seedling establishment. Although a positive interspecific relationship between seed mass and seedling dry mass is well established, much less is known about the relationships among seed mass, seedling mass and RGR within species. We examined relationships among seed mass, seedling mass and RG...

The beet armyworm, Spodoptera exigua, is one of the most important pests of sugar beet in Iran. The aim of this study was to determine the effect of water and nitrogen treatments of sugar beet planton developmental time and fecundity life table parameters of the pest. An experiment was carried out under laboratory conditions (25±2oC, 70±5% R.H. and 12L: 12D) on larvae reared...