in order to determine the critical period of weed control (cpwc) in corn (zea mays l.), an experiment was carried out in a randomized complete blocks design with 14 treatments and three replications during 2013 growing season in the nahavand climatic conditions. two series of the treatments including weed-free and weed-infested were applied in the regular time distances of 10, 20, 30, 40, 50 an...

Nutrient (N) stress affects cotton growth, primary physiological processes andfiber properties. This study utilized two sunlit growth chambers to compare cotton(cv. TM-1) responses to two levels of N nutrition imposed at the onset of floweringstage of development, 100 and 0% of optimum N, in plants grown under otherwiseoptimal temperature and soil moisture conditions. Flowers and bolls were tag...

hydroponics technique accompanied by adjustment of nutrient solution seems to optimize crop production and help in establishing sustainable agriculture. in recent years, the greenhouse production of cucumber has been increased in iran, however there are just a few proper nutrient solutions employed in growing the crop. in line with this, an experiment was conducted to find the effect of various...

The aim of this study was to analyze the effect of drought stress on the kinetics of leaf elongation in relationship to the variation of sugar concentrations and their net deposition rates along the elongation zone of leaf 4 of durum wheat plants. Plants were grown in soil in a naturally illuminated greenhouse, and water...

Leaves are most vulnerable to herbivory during expansion. We hypothesised that one factor favouring small leaves could be that smaller-leaved species have shorter expansion times and are therefore exposed to high levels of herbivory for a shorter period than large leaves. In order to test this hypothesis, leaf expansion time and leaf area loss were measured for 51 species from Sydney, Australia...

limited water for irrigation and the coincidence of early growth of sugar beet (beta vulgaris l.) with the late growth of winter cereals in the northeast (ne) of iran, force farmers, to allocate their limited irrigation water to the cereal crops and thus their sugar beet crop is subjected to an early water stress. finding cultivars which are able to withstand early water stress without a si...

today, the production of healthy and high quality seedlings is the main factors of success in growing vegetables such as tomato. hence, in order to investigate the effect of different levels of vermicompost and nitrogen on the growth parameters of tomato seedlings (lycopersicon esculentum mill. cv. rio grande), a factorial experiment was conducted in a randomized complete design with three repl...

Rates of photosynthesis, dark respiration, and leaf enlargement were studied in soil-grown corn (Zea mays), soybean (Glycine max), and sunflower (Helianthus annuus) plants at various leaf water potentials. As leaf water potentials decreased, leaf enlargement was inhibited earlier and more severely than photosynthesis or respiration. Except for low rates of enlargement, inhibition of leaf enlarg...