Shoot N concentration in plants decreases as they get bigger, due to the fact that N accumulates less rapidly than dry matter in plants during the plant growth process, leading to an allometric relationship between shoot N content (N(sh)) and shoot mass (W(sh)): N(sh)=a(W(sh))b. The results obtained on lucerne plants growing either under controlled low density conditions or in dense stands unde...

The present study was conducted to investigate the effect of growth regulator NAA on in vitro shoot proliferation, rooting, and plantlet establishment. Among the different concentrations of NAA, the best increase in shoot weight (0.25 g) and shoot number (8.83) were observed from 0.1 mg/I NAA. The highest shoot length (2.60 cm), number of leaves (4.83), number of roots (5.15), and root length (...

A laboratory trial was conducted to determine whether suspensions of ZnO nanoparticles (ZnO NPs) could interfere with the early growth of fenugreek. This plant species is one of the recommended species by Organization for Economic Cooperation and Development (OECD). Nine concentrations of ZnO NPs (10, 50, 100, 500, 1000, 2000, 3000, 4000, and 5000 mg/L) were prepared in deionized )DI( water (co...

In order to investigate the effect of growth media and nutrition method on the growth of Bellis perennis L. and nutrients uptake, a factorial experiment was conducted with two factors: growth media (municipal waste compost, Azolla compost, tea wastes compost) and nutrition method (without fertilizer, soil application, foliar spray) in comparison to the control medium (60% soil + 20% manure + 10...

Trees have been increasingly considered as modular organisms, with individual shoots forming autonomous units that respond semi-independently to their surrounding environment. However, there is evidence for fairly strict hormonal control of tree crown development. Studies on the hydraulic architecture of trees suggest a closer functional connection between shoots and crown development than is p...

Resolving the physiological mechanisms by which rhizobacteria enhance plant growth is difficult, since many such bacteria contain multiple plant growth-promoting properties. To understand further how the 1-aminocyclopropane-1-carboxylate (ACC) deaminase (ACCd)-containing rhizobacterium Variovorax paradoxus 5C-2 affects plant growth, the flows and partitioning of mineral nutrients and abscisic a...

The growth-inhibiting effects of indole-3-acetic acid (IAA) at high concentration and the synthetic auxins 7-chloro-3-methyl-8-quinolinecarboxylic acid (quinmerac), 2-methoxy-3,6-dichlorobenzoic acid (dicamba), 4-amino-3,6, 6-trichloropicolinic acid (picloram), and naphthalene acetic acid, were investigated in cleavers (Galium aparine). When plants were root treated with 0.5 mM IAA, shoot epina...

In the present study, the in vitro response of MM.106 apple rootstock to increasing concentrations of NaCl (0, 20, 40, 80, 100 and 120 mM) in the Murashige and Skoog culture medium was analyzed. Explant growth was seriously affected by salinity treatments. Elevated salinity from 20 (control) to 40, 80, 100 and 120 mM NaCl resulted in reduction in shoot growth (shoot number, length and fresh wei...

The physiological and metabolic mechanisms behind the humic acid-mediated plant growth enhancement are discussed in detail. Experiments using cucumber (Cucumis sativus) plants show that the shoot growth enhancement caused by a structurally well-characterized humic acid with sedimentary origin is functionally associated with significant increases in abscisic acid (ABA) root concentration and roo...