ISSN:0190-4167    

DOI:10.1080/01904168409363311

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0190-4167    

DOI:10.1080/01904168409363312

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Growth and macronutrient uptake in two species of cattail,Typha latifoliaandT.domingensis, were determined during an annual growth cycle in Par Pond, a thermally‐graded nuclear reactor cooling reservoir in South Carolina. Shoots of the same age class were sampled periodically from the initiation of growth in early spring to senescence in late autumn. Although differences between thermal regimes were mostly statistically non‐significant, growth and macronutrient uptake, especially of N, P, and K, tended to be enhanced by elevated water temperatures. The pattern for growth and N, P, and K uptake in decreasing order were: “Warm”; > “Intermediate”; > “Ambient”; regimes. The non‐significant statistics were attributed to large between‐stand and between‐temperature regime variations. BothTyphaspecies exhibited sharp declines in N, P, and K concentrations in the shoots, and some decline in the rhizomes, early in the growing season, followed by either a more gradual decline or leveling off of concentrations until senescence. Calcium in shoots of both species increased with season, whereas Mg remained fairly constant. Thermal effluents can alter the growth form ofTypha, as confirmed by the elimination ofT. domingensisin the “Warm”; regime, and can affect their mineral nutrition.

ISSN:0190-4167    

DOI:10.1080/01904168409363313

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Micronutrient uptake by two species of cattail,Typha latifoliaandT.domingensis, in a thermally‐stressed South Carolina lake was determined throughout a growing season. Plants of the same age class were sampled from shoot emergence in early spring to shoot senescence in late fall. The uptake pattern varied according to the element, season, and for some elements, thermal regime. In addition, interspecific differences in uptake were observed, with higher elemental concentrations usually occurring inT. latifoliashoots. In both species, Zn and Fe tended to accumulate in the rhizomes, whereas Mn and B accumulated in shoots. Copper concentrations were equivalent in both shoots and rhizomes. Zinc was the only micronutrient to demonstrate a consistent decrease in shoot concentration in bothspecies early in the growing season followed by a gradual decline or leveling off in concentration over the rest of the season. The other micronutrients exhibited inconsistent uptake patterns. Iron was the only micronutrient to exhibit consistent enhanced effects due to temperature elevation throughout the growing season. In general, larger variabilities were observed in micronutrient uptake than in macronutrient uptake.

ISSN:0190-4167    

DOI:10.1080/01904168409363314

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Sorghum (Sorghum bicolor L. Moench) cv. CSH‐7, an Fe‐efficient hybrid was grown and subjected to Fe‐deficiency stress. The nutrient medium was extracted for isolation of reductant chemicals. By means of thin layer chromatography, I.R. spectrum and HPLC analysis, dibutyl phthalate was identified as the principal component. This chemical was not found in the nutrient medium extracted before the onset of chlorosis or in that after the plants recovered from chlorosis. Furthermore, synthetic dibutyl phthalate and that obtained from the exudate when supplied to the nutrient medium caused greening of chlorotic sorghum in 24 hours. Evidence that the root medium of the Fe‐efficient sorghum can induce recovery of an Fe‐inefficient sorghum grown together, has also been obtained. It is concluded that dibutyl phthalate released by the Fe‐efficient sorghum subjected to stress, is responsible for making Fe available for utilisation. The mechanism of action of dibutyl phthalate on chlorosis recovery is still an open question.

ISSN:0190-4167    

DOI:10.1080/01904168409363315

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Nodulating and non‐nodulating soybeans were grown on a Alfic Udipsamment and a Typic Hapludoll amended with 10 or 100 kg N/ha. Tissue and grain samples were analyzed to determine N2‐fixation, dry matter, and N, P, and K accumulation. Highest grain yields were associated with the highest levels of N2‐fixation and N and K accumulation in grain. The largest dry matter production was by nodulating plants grown on a high soil N regime. Nodulating plants accumulated more grain and tissue N, P, and K than non‐nodulating plants. Nitrogen stress increased P concentrations in both grain and tissue and decreased harvest indices.

ISSN:0190-4167    

DOI:10.1080/01904168409363316

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Aerated solution culture is frequently used for studying plant growth. Few comparisons have been made of root growth in solution with that found in soil. The objective of this study was to compare root growth and root hair development in these two mediums. Corn (Zea maysL.) grown in aerated solution at two temperatures (18 and 25°C) and three P concentrations (2, 10, and 500 μmol L‐1) was compared with that in three soils, Raub (Aquic Argiudoll) and two Chalmers (Typic Haplaquoll) silt loams, in a controlled climate chamber over 21d. Corn plant weight and root growth were similar in solution culture and Raub soil when grown at an air and soil temperature of 18°C. At 25°C both yield and root growth were greater in Raub soil, even though P uptake by corn was 7‐fold greater in solution culture. The same difference was found when corn grown at 25°C in solution culture at 3 different P concentrations was compared with that grown in Chalmers soil at two P levels. Percentage of total root length with root hairs, root length and density and consequently root surface area, were all greater in the Chalmers soil than in solution culture. An increase in soil P, resulted in a decrease in root hair growth. No such relationship was found in solution culture. Although the recovery and measurement of plant roots and root hairs is more convenient in solution culture, results from this study indicate that the usefulness of solution culture for determining those factors which control root growth and root hair development in soil is limited.

ISSN:0190-4167    

DOI:10.1080/01904168409363317

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Lines ofLeucaena leucocephala(Lam.) de Wit were grown in greenhouse pots of an acid, Al‐toxic Tatum subsoil (clayey, mixed, thermic typic Hapludult) treated with 0 or 3000 ppm CaCO3to give final soil pH values of 4.1 and 5.3, respectively. Lines ofL. leucocephala, plus those of otherLeucaenaspecies, were also tested on an acid, Monmouth soil (clayey, mixed, mesic, typic Hapludult) treated with 0 or 1500 ppm CaCO3to give final soil pH values of 4.8 and 6.6, respectively. The major index of acid soil tolerance used was relative root yield (unlimed/limed%).

ISSN:0190-4167    

DOI:10.1080/01904168409363318

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0190-4167    

DOI:10.1080/01904168409363319

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0190-4167    

DOI:10.1080/01904168409363310

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor