in order to investigate the effect of different weed-free and weed-infested periods on the growth indices of black seed, a field experiment was conducted at the agricultural research station of ferdowsi university of mashhad, during 2009-2010 growing season. the experiment was laid out in randomized complete block design with 12 treatments and 3 replications. twelve experimental treatments cons...

Long-term declines in rainfall in south-western Australia have resulted in increased interest in the hydraulic characteristics of jarrah (Eucalyptus marginata Donn ex Smith) forest established in the region's drinking water catchments on rehabilitated bauxite mining sites. We hypothesized that in jarrah forest established on rehabilitated mine sites: (1) leaf area index (L) is independent of in...

to evaluate the effects of water deficit stress in barley germplasm collection of national gene bank ofiran, 25 genotypes collected from arid and semi arid provinces of iran and 3 sample cultivars werestudied in two environments including: non-stressed and water deficit stress. agronomical, phenologicaland morphological traits were measured. stress indices were calculated to determine tolerant ...

Leaf characteristics of mature 2, 3 and 4-year-old North American ginseng (Panax quinquefolius L.) leaves on fruiting and non-fruiting (NF) plants were studied. Leaflets of the 2-year-old plants had the lowest fresh and dry weight, area, volume and internal gas volume. Inflorescence removal in 3-year-old plants did not affect leaf characteristics or ginsenoside concentration but in 4-yearold pl...

The basis used for expression of carbon dioxide exchange rate (CER) of single leaves may alter the relative ranking of genotypes being selected for a breeding program. Therefore, field and growth chamber experiments were conducted on 16 genotypes of tall fescue (Festuca arundinacea Schreb.) to determine the relative merit of expressing CER data on a leaf area or leaf weight basis. Genotypes wer...

abstract the propose of this study was evaluation of cropsyst model on growth simulation and yield stimation of canola under different irrigation treatments. canola (talaye) was sown under 5 treatment and 4 replicants in completed randomized block designs at the college of agriculture, shiraz universityduring 2007-2008. during the growth season dry mass and lai was meseaured frequently, then mo...

Elliott, K.J. and White, AS., 1993. Effects of competition from young northern hardwoods on red pine seedling growth, nutrient use efficiency, and leaf morphology. For. Ecol. Manage., 57. 233255. The effects of competition from three northern hardwood tree species on red pine (Pinus resinosa Ait. ) seedlings were examined on two clear-cut sites in western Maine. We examined how planted red pine...

Greater leaf thickness is usually associated with greater leaf carbon assimilation rate, but the tradeoff between thicker versus larger leaves also affects canopy structure and light interception. Many studies equate the ratio of dry leaf mass to area (leaf specific mass) with leaf thickness. This approximation has utility but ignores differences in true thickness due to variation in water or a...