A system was evaluated for growing plants at reproducible levels of water stress. Beans (Phaseolus vulgaris L.) were grown in vermiculite, transferred to a semipermeable membrane system that encased the root-vermiculite mass, and then placed into nutrient solutions to which various amounts of polyethylene glycol (PEG) 20M were added to control solution water potential. The membrane (Spectrapor ...

The paper considers a simple model of radially symmetric cell which undergoes growth due to a continuous supply of nutrient, and disintegration as a result from the various tasks the cell performs. The boundary of the cell is a \free boundary", unknown in advance, which evolves by responding to both the growth and disintegration processes. If the nutrient concentration (at in nity) exceeds a ce...

Roots of potato plants (Solanum tuberosum cv Bintje) growing on low Fe nutrient solution developed the characteristic Fe efficiency reactions, such as high ferric reductase activity, proton extrusion and increased root hair formation. Roots from a tuber with sprout removed, when grown on Fe-free nutrient solution, also expressed these reactions; transfer to iron-containing medium resulted in th...

the present study was laid out in order toevaluate the effect of salinity on some biochemical characterize of grapevine c.vyaghouti. the experiment was done at agricultural and natural resources research center, ilam, iran at 2014. the experiment was a completely block design (crd) with four replications. saline factor was nacl salinity in seven levels (zero, 50, 100, 150, 200 and 250 mm). grap...

Kalanchoë blossfeldiana Poelln. cv Hikan plants were grown hydroponically with nutrient solution containing 5 millimolar NO(3) (-) (or NH(4) (+)) for 1 to 2 months and then transferred to nutrient solution containing no nitrogen. CO(2) uptake at night, nocturnal increase in titratable acidity, and activity of phosphoenolpyruvate carboxylase increased after the transfer. Thus, transfer to nitrog...

this study was conducted to choose the best species for plantation on a poor drainage soil in southern coast of caspian sea, iran. nutrient concentrations in live and senescent leaves and soil properties were compared among alnus subcordata c.a.mey (n-fixing tree), populus deltoides­ marsh. (non n-fixing tree)and taxodium distichum (l.) rich. (coniferous tree) plantations. in each of these plan...

It is shown that Saharan soil has the potential of producing bioavailable iron when illuminated with visible light and also it contains some essential macronutrient and micronutrient elements. In this study, these properties of the desert soil were tested on the certified wheat cultivars (Triticum aestivum L. var. gonen 98) using Hewitt nutrient solution, illuminated and non-illuminated soil so...