Root systems

Abaca. The abaca fiber is obtained from the leaves of the banana-like plant (same genus) Musa textilis (banana family, Musaceae). The fiber is also called Manila hemp from the port of its first shipment, although it has no relationship with hemp, a bast fiber. The mature plant has 12—20 stalks growing from its rhizome root system the stalks are 2.6—6.7 m tall and 10—20 cm thick at the base. The stalk has leaf sheaths that expand iato leaves 1—2.5 m long, 10—20 cm wide, and 10 mm thick at the center the fibers are ia the outermost layer. The plant produces a crop after five years, and 2—4 stalks can be harvested about every six months. 

Transpiration is the movement of water from the root system up to the leaves and its subsequent evaporation to the atmosphere. This process moves nutrients throughout the plant and cools the plant. Respiration is a heat-producing process resulting from the oxidation of carbohydrates by O2 to form CO2 and H2O, as shown in Eq. (8-2). 

The indirect pathway by which air pollutants interact with plants is through the root system. Deposition of air pollutants on soils and surface waters can cause alteration of the nutrient content of the soil in the vicinity of the plant. This change in soil condition can lead to indirect or secondary effects of air pollutants on vegetation and plants. 

Wurzel-stock, m. rootstock, rhizome, -stoff, m. (Old Chem.) radical principle, -werk, n. root system, -zeichen, n. radical sign. 

Although seen only occasional during the first half of this century, winter injury of first-year red spruce needles has become an annual event in the coniferous montane forest area, resulting in the formation of red-brown first year needles that subsequently desiccate and are shed 20, 21). The loss of foliage reduces photosynthesis and the obligatory accumulation of carbohydrate in the twigs and root systems. There is some evidence that this phenomenon involves both natural and anthropogenic causal factors. 

Sensing of soil drying by the plant root system and the resulting regulation of shoot physiology... 

Fig. 9. Leaf water potential and turgor, abaxial stomatal conductance, and ABA content of abaxial epidermis of leaves of Commelina plants which were grown with their root systems divided between two pots. Water was either applied daily to both halves of the root system (A) or was withheld from one half of the root system after day 1 of the experimental period (A). Points for water relations and conductance are means s.e. Modified from Zhang, Schurr Davies (1987).

Jordan, W.R. Miller, F.R. (1980). Genetic variability in sorghum root systems implication for drought tolerance. In Adaptation of Plants to Water and High Temperature Stress, ed. N.C. Turner and P.J. Kramer, pp. 383-400. New York Wiley Interscience. 

McGowan, M., Blanch, P., Gregory, P.J. Haycock, D. (1984). Water relations of winter wheat. 5. The root system and osmotic adjustment in relation to crop evaporation. Journal of Agricultural Science, Cambridge, 102, 415-25. 

The interaction of plants and bacteria in the root system plays an important role in the remediation of contaminants, and may involve the use of plant exudates to stimulate the growth of degradative bacteria as well as the penetration of the soil by plant roots (Kuiper et al. 2004) ... 

Microbial degradation in the root system of higher plants can be significant. 

Patten CL, BR Glick (2002) Role of Pseudomonas putida indoleacetic acid in development of the host plant root system. Appl Environ Microbiol 68 3795-3801. 

As mentioned before and in Chaps. 4 and 6, the concentration of rhizode-position decreases as the distance from the rhizoplane increases, whereas the opposite generally occurs for the concentration of any plant nutrient in soil. In this context, the role of rhizospheric soil, rather than that of the bulk soil, is crucial for plant nutrition. It has also to be considered that very different situations can occur depending on the type of nutrient (24) and the nutritional status of plants (see Chap. 3) furthermore, different portions of the root system are characterized by differential nutrient-specific rates of uptake (25). All the above statements point to the necessity of reconsidering the concept of plant nutrient availability giving more importance to the situation occurring in the soil surrounding the root. 

R. Scott Russell, Plant-Root System Their Functions and Interactions with Soil. McGraw-Hill, London, 1977. 

M. C. Drew, L. R. Saker, Nutrient supply and the growth of the seminal root system in barley II. Localized compensatory changes in lateral root growth and the rates of nitrate uptake when nitrate is restricted to only one part of the root system. J. E.xp. Bot. 26 79 (1976). 

K. P. Barley, The configuration of the root system in relation to nutrient uptake. Adv. Agron. 22 159 (1970). 

---