Split-root system

Crop plants versus weeds. Both thin and dense field stands of Kentucky-31 fescue were observed by Peters (68) to be relatively free of weeds. Extracts of fescue, sand cultures, and split-root-system experiments demonstrated that fescue produced toxic chemicals which exuded from the roots and inhibited growth of wild mustard and birdsfoot trefoil. 

Reynolds, P.H.S., Boland, M.J., McNaughton, G.S., More, R.D. Jones, W.T. (1990). Induction of ammonium assimilation leguminous roots compared with nodules using split root system. Physiologia Plantarum 79, 359-67. 

Some early work suggested that symbiotic infection may result in ISR. In that work, a split root system was used and it was discovered that inoculation on one side of the root followed by later inoculation on the second side of the roots resulted in nodules on the first side and inhibition of nodulation of the second side (Kosslak and Bohlool, 1984 Sargent et al., 1987). It is not known if this effect is a result of an LPS caused ISR. However, it has been reported that rice plants inoculated with R. leguminosarum biovar trifolii have an increased production of phenolics... 

Kosslak, R.M., Bohlool, B.B. Suppression of nodule development on one side of a split root system of soybean caused by a prior inoculation of the other side. Plant Physiol 75 (1984) 125-130. 

Fig. 2.3 Conttiiners a Wheaton glass bottles, b split-root systems, c soil cups, and d soil columns...

Lyu S-W, Blum U (1990) Effects of fendic acid, an adelopathic compound, on net P, K, and water uptake by cucumber seeddngs in a split-root system. J Chem Ecol 16 2429-2439 Lyu S-W, Blum U, Gerig TM, O Brien TE (1990) Effects of mixtures of phenolic acids on phosphorus uptake by cucumber seedlings. J Chem Ecol 16 2559-2567 MaMno T, Takahashi Y, Sakurai Y, Nanzyo M (1996) Infiuence of soil chemical properties on adsorption and oxidation of phenodc adds in sod suspension. Soil Sci Plant Nutr 42 867-879... 

Containers a Wheaton glass bottles, b split-root systems,... 

Furthermore, when part of the receiver s root system was placed in nutrient solution (split-root technique), the receiver grew much better. The authors concluded that quackgrass caused an allelopathic inhibition of K+ and N uptake by maize (12). 

Sargent, L., Huang, S.Z., Rolfe, B.G., Djordjevic, M. Split-root assays using Trifolium subterra-neum show that Rhizobium infection induces a systemic response that can inhibit nodulation of another invasive Rhizobium strain. Appl Environ Microbiol 53 (1987) 1611-1619. 

Tliis is made up of the primary root ealled the tap root with lateral secondary roots branching out from it and, from these, tertiary roots possibly developing obliquely to form, in some cases, a very extensive system of roots (Fig. 1.14). The root of the bean plant is a good example of a tap root system. If this is split it will be seen that there is a slightly darker central woody eore, the skeleton of the root, which helps to anchor the plant and transport foodstuffs. The lateral seeondary roots arise from this central core (Fig. 1.15). Carrots and other true root crops such as... 

The determination of the nature of the roots of the characteristic equation (or the poles of the corresponding system transfer function) forms the basis of many techniques used to establish the nature of the stability of the system. In order to calculate the step response, equation 7.118 must be split into partial fractions for inversion, thus ... 

On the tetragonal elongation the ground CFT is 3/42g, and this case could behave like the ZFS system with S = 1. The exact multiplet splitting between A (ground) and A (first excited state) is S15/he = Dni = 105 cm-1, whereas the SH projection gives only Ds i/hc = 36 cm-1. This discrepancy has roots in the Cl of the multiplets of the same symmetry, i.e., A—A and A... A, when the complete dn space is active. 

Cultural and intellectual diversity. Our no less diverse cultural heritages, belief systems, concerns, and prejudices epitomized by the still significant split between Western medicine rooted in Hippocrates and Galen, and the enduringly popular systems of alternative and Eastern medicine. 

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