摘要:

A field study was made of the seasonal changes in dry‐matter production, and the uptake, distribution, and redistribution of 12 mineral nutrients in the semi‐dwarf spring wheat, Egret, grown under typical irrigation farming conditions. Most of the dry‐matter production and nutrient uptake had occurred by anthesis, with 75–100% of the final content of magnesium (Mg), copper (Cu), chloride (Cl), sulfur (S), phosphorus (P), nitrogen (N), and potassium (K) being taken up in the pre‐anthesis period. The above‐ground dry‐matter harvest index was 37%, and grain made up 76% of the head dry matter. Redistributed dry matter from stems and leaves could have provided 29% of the grain dry matter. Concentrations of phloemmobile nutrients, such as N and P, decreased in the leaves and stems throughout the season, whereas concentrations of phloem‐immobile nutrients, such as calcium (Ca) and iron (Fe), generally increased. The decline in the N concentration in stems and leaves was not prevented by N fertilizer applied just before anthesis. Leaves had the major proportion of most nutrients in young plants, but stems had the major proportion of these nutrients at anthesis. Grain had over 70% of the N and P, and 31–64% of the Mg, manganese (Mn), S, and zinc (Zn), but less than 20% of the K, Ca, sodium (Na), Cl, and Fe in the plant. Over 70% of the N and P, and from 15 to 51% of the Mg, K, Cu, S, and Zn was apparently redistributed from stems and leaves to developing grain. There was negligible redistribution of Ca, Na, Cl, Fe, and Mn from vegetative organs. Redistribution from stems and leaves could have provided 100% of the K, 68–72% of the N and P, and 33–48% of the Zn, Cu, Mg, and S accumulated by grain. It was concluded that the distribution patterns of some key nutrients such as N, P, and K have not changed much in the transition from tall to semi‐dwarf wheats, and that the capacity of wheat to redistribute dry matter and nutrients to grain is a valuable trait when nutrient uptake is severely restricted in the post‐anthesis period.

ISSN:0190-4167    

DOI:10.1080/01904169409364807

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Sorghum [Sorghum bicolor(L.) Moench cv RTX430, SC214, SC574, SC599, TAM428, and SC326xSC103] were grown on soils of pH 4.2 or 6.2–6.5. Leaf and nonexserted juvenile panicle tissues were collected at 75 days after planting. Fresh and dry weights were measured and element contents [sulfur (S), phosphorus (P), magnesium (Mg), calcium (Ca), potassium (K), zinc (Zn), iron (Fe), and copper (Cu)] were measured by atomic absorption. Significant cultivar differences in ion concentration (μmol/g dry weight) were found. Juvenile panicles had higher ion concentration (μmol/g dry weight) [S, P, Mg, Ca, K, Zn, and Cu) than leaves. Within leaf tissue, ion concentration (μmol/g dry weight) was correlated with tissue water content (g water/g dry weight).

ISSN:0190-4167    

DOI:10.1080/01904169409364808

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Manganese (Mn) deficiency is a problem in soybeans grown on high pH soils, which to date can only be controlled by chemical fertilizers. In view of the success of genetic resistance in reducing yield losses associated with iron (Fe) deficiency chlorosis, a one year study was initiated to determine whether genetic resistance could be used to control Mn deficiency related yield losses. For this study, twenty soybean genotypes ranging from Group I maturity to Group III maturity were planted at five locations which had previously exhibited symptoms of Mn deficiency. Individual plots were rated for Mn‐deficiency symptoms on a 1–5 scale (1 = no yellowing to 5 = severe yellowing with some necrosis) at the Rl growth stage and plants in the center rows were harvested for yield. The mean Mn‐deficiency rating was 2.8 with a range from 1.8 for NKS 23–03 and P9181 to a 3.9 for A3205. The mean yield was 3059.3 kg/ha with a range from 3670.6 for A3205 to 2567.5 kg/ha for Chapman. The correlation between Mn‐deficiency rating and yield was not significant presumably due to the high yields of some of the later maturing cultivars.

ISSN:0190-4167    

DOI:10.1080/01904169409364809

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Denitrification rates under various tillage systems were determined in the corn(Zea maysL.) cycle of a corn‐oats(Avena sativaL.) rotation. Denitrification was measured directly with anin‐situsoil cover method which supplied the soil with acetylene (C2H2) and evacuated the nitrous oxide (N2O) produced. Denitrification rates were measured in both a field or non‐wheel track (NWT) area and in a compacted wheel track (WT) area for the no‐till (NT), chisel plow (CH), moldboard plow (MP) tillage systems after nitrogen (N) was applied by broadcast/incorporation with 112 kg N/ha as ammonium nitrate. Nitrogen was also applied to the NT treatment by injection with modified anhydrous ammonia knives prior to planting. Most of the cumulative N loss occurred over a 22 day period following heavy rainfall in June. Denitrification was greatest on days after rainfall events for the NT systems. Cumulative N loss was estimated at 25, 16, and 11 kg N/ha from May 29‐September 8 for NT, CH, and MP treatments, respectively, for the broadcast/incorporated N application. Mean denitrification rates from WT areas were about 1.6 times greater than the NWT areas.

ISSN:0190-4167    

DOI:10.1080/01904169409364810

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Under conditions of salt stress, plants show qualitative and quantitative alterations in various organic compounds, such as nitrogen (N) compounds and organic acids. In this work, the effect of different saline levels as well as various N levels, supplied as nitrate (NO3) or as ammonium (NH4)+NO3on the concentration of amino acids and organic acids in the leaves of tomato and cucumber plants has been studied. The effect of the source of N on individual amino acid contents varied with plant species. Most of the amino acids increased when the concentration of N in the nutrient solution was increased, except when N was added as NH4+NO3for tomato. The effect of salt stress depended on which amino acid was considered. The data also indicate that the effect of salinity on each particular amino acid was greatly dependent on the plant species and N source. Organic acids were differently affected by salinity and by the N source, depending on the plant species. In tomato, the concentrations of short‐chain organic acids were 2–3 times higher in NO3‐supplied plants than in those grown with NH4+NO3. Finally, in cucumber, malic acid concentration increased as a function of the saline level in the medium.

ISSN:0190-4167    

DOI:10.1080/01904169409364811

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The effect of three waste waters from two factories, Manquabad (fertilizer) and Bani Quara (detergents and oils), and a sewage effluent from Arab El‐Madabegh (sewage effluent) on the soluble nitrogen and carbon fractions in sunflower plants was studied. In addition, tissue concentrations of sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), chloride (Cl), sulfur (S), phosphorus (P), zinc (Zn), manganese (Mn), copper (Cu), and iron (Fe) were determined. Plants analyzed monthly that were grown in waste waters were found to have significantly higher soluble sugar, hydrolysable carbohydrate, and soluble protein in both their shoots and roots than plants grown in tap water (control). No definite pattern was noted for amino acid responses to the waste water treatment. Element concentrations in the plants were variable, affected by the pollution source differences and monthly sampling. Waste waters significantly enhanced the accumulation of most elements in both shoots and roots. The most notable effect was the increase in the Na, Cl, and Zn concentrations. In addition, waste waters significantly decreased the K content in both shoots and roots. Plants growing in Manquabad waste waters have the highest concentration of Zn, Mn, and Fe. The internal concentration for the mineral elements in the plant tissue was postively and negatively correlated with that found in the waste waters. The negative correlations existed with most elements in the plant tissue and waste waters, indicating the presence of an active regulation system that influenced the element uptake from the waste waters.

ISSN:0190-4167    

DOI:10.1080/01904169409364812

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Seminal root‐tips (1‐cm) ofPaspalum vaginatumSwartz cv Sea Island I were evaluated for the influence of PCMBS (0, 0.01, 0.1, or 1 mM), nifedipine (0, 0.01, 0.1, or 1 μM), verapamil (0, 0.01, 0.1, or 1 mM), diltiazem (0, 0.01, 0.1, or 1 mM) orthovanadate (0, 0.01, 0.1, or 1 mM), nitrate (NO3‐) (0, 0.01, 0.1, or 1 mM), and ammonium, (NH4+) (0, 0.01, 0.1, or 1 mM) on calcium (45Ca2+) absorption. Calcium absorption was inhibited by the Ca2+‐channel blockers (i.e., nifedipine, verapamil, and diltiazem) and the H+‐ATPase or Ca2+‐ATPase inactivator, PCMBS. Sea Island I seminal root‐tips were vanadate‐insensitive and NO3‐sensitive, indicating the presence of tonoplast‐type ATPases and very little (or none) activity of PM‐type ATPases on the PM. Ammonium did not influence45Ca2+absorption by Sea Island I seminal root‐tips.

ISSN:0190-4167    

DOI:10.1080/01904169409364813

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

p ‐ Chloromercuribenzenesulfonic acid (PCMBS) (0, 0.01, 0.1, or 1 mM) was evaluated for influence on calcium (Ca), phosphorus (P), boron (B), zinc (Zn), manganese (Mn), iron (Fe), magnesium (Mg), and copper (Cu) uptake during 1‐hr exposure by 1‐cm root tips of seedlingSorghum bicolor(L.) Moench, cv GP‐10, SC 283, Funk G522DR, and SC 574 grown in Hoagland and Arnon complete mineral nutrient solution. Calcium uptake was inhibited by PCMBS (1 mM) in all four cultivars, but genetic differences in response were evident. Responses of the cultivars to PCMBS influence on the uptake of other elements showed complete genetic diversity within each element measured and among cultivars within each element.

ISSN:0190-4167    

DOI:10.1080/01904169409364814

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Soil acidity is often associated with toxic aluminum (Al), and mineral uptake usually decreases in plants grown with excess Al. This study was conducted to evaluate the effects of Al (0, 35, 70, and 105 μM) on Al, phsophorus (P), sulfur (S), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn,) and copper (Cu) uptake in shoots and roots of sorghum [Sorghum bicolor(L.) Moench, cv. SC283] colonized with the vesicular‐arbuscular mycorrhizal (VAM) fungi isolatesGlomus intraradicesUT143–2 (UT143) andGlomus etunicatumUT316A‐2 (UT316) and grown in sand (pH 4.8). Mycorrhizal (+VAM) plants had higher shoot and root dry matter (DM) than nonmycorrhizal (‐VAM) plants. The VAM treatment had significant effects on shoot concentrations of P, K, Ca, Fe, Mn, and Zn; shoot contents of P, S, K, Ca, Mg, Fe, Mn, Zn, and Cu; root concentrations of P, S, K, Ca, Mn, Zn, and Cu; and root contents of Al, P, S, K, Ca, Mg, Fe, Mn, Zn, and Cu. The VAM effects on nutrient concentrations and contents and DM generally followed the sequence of UT316 > UT143 > ‐VAM. The VAM isolate UT143 particularly enhanced Zn uptake, and both VAM isolates enhanced uptake of P and Cu in shoots and roots, and various other nutrients in shoots or roots.

ISSN:0190-4167    

DOI:10.1080/01904169409364815

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Iron (Fe)‐stress response and symbiotic nitrogen (N2) fixation are chemical reduction processes within the roots which interact to the extent that nodulated, Fe‐stressed, Fe‐inefficient soybean initiates Fe‐stress response, but similar nonnodulated soybean does not. The objective of this study was to examine the relationship between nitrogenase activity and Fe‐stress response in the Fe‐inefficient T203 soybean by inoculating plants with effective or ineffective strains ofBradyrhizobium japonicumon either side of split‐root systems. Half the roots of each plant were either inoculated with effective or ineffective strains or left uninoculated. Nodules formed on roots inoculated with the ineffectiveB. japonicumstrain, SM5, were similar in number and shape to those on roots inoculated with the effective strain, 61A209, but roots inoculated with SM5 were free of nitrogenase activity. Hydrogen ion and reductant were not released from uninoculated roots or roots inoculated with SM5, but were released from active, effective nodules and the roots below the active nodule clusters of roots inoculated with effectiveB. japonicum.Plants with effective and ineffective strains inoculated on either half of the roots exhibited Fe‐stress response only on the half with nitrogenase activity. Plants inoculated with both effective and ineffective strains, but provided nitrate to inhibit nitrogenase activity, lacked Fe‐stress response and became severely Fe chlorotic. Iron reduction and hydrogen (H+) release around nodules and roots of inoculated Fe‐inefficient T203 soybean is keyed to nitrogenase activity.

ISSN:0190-4167    

DOI:10.1080/01904169409364816

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor