field experiment was conducted to assess the efficacy of wheat residues and different densities of sunflower in weed control during 2007 growing season. the experimental design was a randomized complete block with three replications. the experiment was set up in factorial arrangement, amount of 0, 1250, 2500, 3750, 5000 kg ha-1 of wheat residue and burning of residue (5000 kg ha-1) were the lev...

The objective of this study was to evaluate variations in the composition and abundance phytoplankton community after an exceptional harmful bloom Akashiwo sanguinea that occurred Todos os Santos Bay (BTS) early March, 2007. Samples were collected every ten days, between April, 2007 2008, from estuarine gradient Paraguaçu River BTS. physical chemical variables measured situ using a multiparamet...

a field experiment was conducted to investigate the spatial distribution of nutsedge (cyperus spp) during rice growing season using geostatic in 2011 at sari agricultural sciences and natural resources university. at the first field was divided into 36 grids (2.5×2.5 meter) after the final preparation. grid intersection points were determined and marked. all samples were taken from these points...

The aim of this study was to investigate the climate change impacts on some factors affecting rainfed wheat growth such as effective rainfall, planting date and length of growing season in four stations located in Chaharmahal and Bakhtiari province. Firstly, it is necessary to predict future (2046-2065) climatic conditions. For this purpose, the output of HADCM3 general circulation model was us...

The vast wetlands on the Tibetan Plateau are expected to be an important natural source of methane (CH4) to the atmosphere. The magnitude, patterns and environmental controls of CH4 emissions on different timescales, especially during the nongrowing season, remain poorly understood, because of technical limitations and the harsh environments. We conducted the first study on year-round CH4 fluxe...

In this study, the relation between leaf area and its dimensions was estimated using a non-destructive method. This method is based on this fact that the leaf shape does not change during the growing season. In this method, leaf area during the growing season is estimated based on the dimensions of the smallest leaf in the initial stage of plant growth or at any growth stage by measuring the le...

The issue of moulds and, thus, contamination with mycotoxins is very topical, particularly in connexion with forages from grass stands used at the end of the growing season. Deoxynivalenol (DON), zearalenone (ZEA), fumonisins (FUM) and aflatoxins (AFL) are among the most common mycotoxins. The aim of the paper was to determine concentrations of mycotoxins in selected grasses (Lolium perenne, Fe...

Riparian cottonwood/willow forest assemblages are highly valued in the southwestern United States for their wildlife habitat, biodiversity, and watershed protection. Yet these forests are under considerable threat from climate change impacts on water resources and land-use activities to support human enterprise. Stream diversions, groundwater pumping, and extended drought have resulted in the d...