prediction of weed emergence timing would help minimize crop yield loss and reducing herbicide use by optimization of the timing of weed control. therefore, seedling emergence evaluation was conducted in different irrigation levels (40, 60, 80, 100 percent of crop water requirement and furrow irrigation) to develop a thermal time seedling emergence model for amaranthus retroflexus l. in sunflow...

jimsonweed (datura stramonium l.) is an important weed in bean fields in iran. in order to investigate the effect of density and relative time of emergence of jimsonweed on yield and yield components of chitti bean, a field study based on factorial experiment was conducted at farm bean research national station in khomein in 2006. treatments were chosen to provide four different weed densities ...

In the groupoid approach to noncommutative quantization of gravity, gravitational field is quantized in terms of a C-algebra A of complex valued functions on a groupoid G = E ×Γ, where E is a suitable space and Γ a group of fundamental symmetries. In the noncommutative quantum gravitational regime the concepts of space and time are meaningless. We study the “emergence of time” in the transition...

determination of cardinal temperatures during seed germination and emergence as well as the thermal time requirement for each stage is essential in crop management and modeling of plant growth and development. two experiments were conducted to predict cardinal temperatures and thermal time requirement for germination and emergence of chickpea genotypes. in the first experiment, seed germination...