Potato crop is the fourth main food crops in the world after maize, rice and wheat. It is characterized by specific temperature requirements and develops best at about 20 ̊C. Forecasts of global warming prompt us to study the tolerance of potato genotypes to heat during the growing season. The aim of this work was to assess the response of chosen potato cultivars to high temperature during the d...

The productivity of temperate grassland is limited by the response of plants to low temperature, affecting winter persistence and seasonal growth rates. During the winter, the growth of perennial grasses is restricted by a combination of low temperature and the lack of available light, but during early spring low ground temperature is the main limiting factor. Once temperature increases, growth...

in order to study of yield, growth index and physiological traits in spring sugar beet genotypes with delayed planting date, a field experiment was carried out in chenaran in khorasan razavi province in the east of iran in 2008 cropping season. for this experiment a complete randomized block design with 4 replications and 6 treatments was used. the experimental treatments were six improved vari...

We used 179 tree ring chronologies of Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] from the International TreeRing Data Bank to study radial growth response to historical climate variability. For the coastal variety of Douglas-fir, we found positive correlations of ring width with summer precipitation and temperature of the preceding winter, indicating that growth of coastal populations w...

The aim of this study was to investigate the presence of nerve growth factor (NGF) and its receptors tyrosine kinase A (TrkA) and p75 in the ovaries of the wild ground squirrels during the breeding and nonbreeding seasons. In the breeding period, NGF, TrkA and p75 were immunolocalized in granulosa cells, thecal cells, interstitial cells and luteal cells whereas in the nonbreeding period, both o...

fire is one of the incorporate vegetation management practices for grasslands and semi-arid rangelands. it may affect symbiotic relationship between range plants and mycorrhiza. accordingly, this research was aimed to investigate the effects of a spring prescribed fire on the symbiotic relationships between mycorrhiza and 6 plant species. the study was conducted in a semi-arid steppe rangeland ...

proportionality of wheat cultivars growth patterns to the area’s agro climatic condition will improve crop production. the objective of this study was identifying the phenology of a wide range of wheat varieties in iran, as well as evaluating the relationship between phenology and drought stress tolerance under late season drought stress. in this experiment, 36 wheat genotypes were studied unde...

The water percolation loss beyond root zone in the soil is one of the important parameters to determine water requirement of rice plant. If the amount of water percolation rate into the soil is estimated more carefully, determination of water requirement will be evaluated better and designing for system of irrigation, drainage and related establishments will be more easily done. The purpose of ...