in this study the effects of source limitation on grain yield of twelve barley cultivars (‘aras’,‘jonub’,‘reihan’,‘zarjou’,‘sararoud’,‘sahra’,‘fajr30’,‘karoun’,‘gorgan’,‘makouei ’and ‘nosrat(’ under post anthesis water deficiency were studied. source limitation treatments were included that control, removing of awn, leaves below flag leaf, flag leaf and spike photosynthesis. all source limitati...

1. Photosynthesis reaches its maximum rate at about the same light intensity over the whole range of chlorophyll concentrations studied. 2. Over this range the process shows the same relationship to temperature. The value of the temperature characteristic decreases gradually as the temperature rises. 3. The rate of photosynthesis is more depressed by prussic acid the lower the chlorophyll conce...

1. Extensive measurements have been obtained (a) relating photosynthesis and light intensity for a large range of CO(2) concentrations and (b) relating photosynthesis and CO(2) at different light intensities. From these families of curves, the limiting factor relationship can be secured for any value of the photosynthesis rate. 2. In terms of previous work an equation has been derived for descr...

The Emerson enhancement effect was evaluated in the intact spinach (Spinacia oleracea var. Long Standing Bloomsdale) chloroplast by monitoring the uptake of (14)CO(2) during illumination by 640 nm and 720 nm lights. Low levels (about 10 mum) of fructose 1,6-diphosphate, ribose 5-phosphate, and glycerate 3-phosphate stimulated the rate of photosynthesis and abolished enhancement values observed ...

Tobacco is a salt-sensitive glycophyte crop species. In this work effect of silicone (Si) supplementation (1 mM as Na2SiO3) was studied in Nicotiana rustica L. cv. Basmas grown hydroponically in growth chamber under control, low (25 mM) and high (75 mM) NaCl concentration for two weeks. Dry matter production of leaves was depressed by salinity level as low as 25 mM and higher salt concentration...

Interactions between photosynthetic substrate supply and temperature in determining the rate of three respiration components (leaf, belowground and ecosystem respiration) were investigated within three environmentally controlled, Populus deltoides forest bays at Biosphere 2, Arizona. Over 2 months, the atmospheric CO2 concentration and air temperature were manipulated to test the following hypo...

application of biofertilizers is a crucial technique for reducing catastrophic effects of irregular utilization of chemical fertilizers. this experiment was carried out to evaluate the effects of rhizobium strains and plant growth promoting rhizobacteria (pgpr) on dry matter partitioning and some growth parameters of chickpea (cicer arientinum l.), arman cultivar. this research was conducted as...