摘要:

Determinate soybean [Glyclne max(L.) Merr.] has been characterized by few detailed micronutrlent partitioning studies. Knowledge of the variation in mlcronutrient concentrations with plant part, nodal position, and plant age is needed for a better understanding of plant functions. In this field study, ‘Bragg’ soybean were grown on an Aquic Paleudult soil (Series Goldsboro loamy sand). Plants were sampled at 10–14 day intervals beginning 44 days after planting (July 7) until harvest. Maximum observed Fe concentrations were 152, 276, 259, and 191 ppm for stem internodes, petioles (+ branches), leaf blades, and pods, respectively. Maximum observed Zn concentrations were 118, 91, 95, and 112 ppm for the same respective plant parts. Maximum observed Mn concentrations were 41, 73, 134, and 63 ppm for the same respective plant parts. Nodal and temporal mean concentra tlons of Fe, Zn, and Mn generally varied considerably due to plant age and nodal position, respectively, in all plant parts. These data document that for plant analysis, mean concentrations of elements in all four plant parts can vary by several fold depending upon plant age and nodal composition of the sample. Regression equations and associated response surfaces will be extremely useful in the development of accurate plant growth models which describe Fe, Zn, and Mn concentrations and translocations among parts of determinate soybean.

ISSN:0190-4167    

DOI:10.1080/01904168609363535

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Nutrient requirements o£ plants during their various phases of growth are affected by several internal and external factors. The changes in rate of uptake by root with age are an important factor to meet the increasing plant demand for nutrients. Nutrient culture experiments were carried out under controlled greenhouse conditions with corn (Zea MaysL.) and alfalfa (MedicagosativaL.) to investigate the relationship of stage of growth to changes in plant parameters and nutrient uptake properties. With advancement of age. both plant species increased their ambient growth medium pH towards neutrality. With increasing age in alfalfa there was very little change in observed S:R ratio and root growth rate. On the other hand in corn plants the S:R ratio increased and growth rate for root and shoot decreased with age. Alfalfa contained higher concentrations of N, K, Na, and Ca than corn; while ion concentrations in both crops decreased with plant age. At all stages of growth, alfalfa absorbed less nutrients than corn. The rates of nutrient influx, Inin both the crops showed various degrees of correlation with age and rate of shoot growth. In corn. Infor ions reached a maximum at 25 days growth; whereas, in alfalfa, Inreached maximum at 30 days of growth. The differences in influx rates for different ions in the two species are probably due to the difference in development of shoot and root parameters and shoot demand for the ions.

ISSN:0190-4167    

DOI:10.1080/01904168609363536

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The relationship between nitrate reductase activity and ferredoxin levels in lemon tree leaves was studied. The experiments were carried out on leaves from full‐nutrient sufficient trees as the reference, and on leaves from trees with several nutritional stresses, mainly iron chlorosis from trees growing under Fe‐stressed conditions.

ISSN:0190-4167    

DOI:10.1080/01904168609363537

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Solution retention by avocado (Persea americanacv. Fuerte) and apple (Mallus domesticaBurkh. cv. Anna) leaves was measured by weight gain of detached leaves after dipping them in solutions of two surfactants and by analysis of various concentrations of urea retainedatzero time on surfaces of attached leaves. Linear regression equations were calulated, relating leaf area and retention of solution. The slope of the equation represents the retention of solution on the leaf surface, and its intercept represents the value retained on the leaf margin. Solution retained on leaf surface was 2.5–2.6 and 5.4–6.4 mg/cm2for ‘old’ avocado and apple leaves, respectively. Retention on the serrated leaf margin of the apple was greater than on the smooth margin of the avocado. The abaxial leaf surfaces retained approximately 62% and 83% of the total solution retained by the avocado and the apple leaves, respectively.

ISSN:0190-4167    

DOI:10.1080/01904168609363538

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The influence of the fungal toxin fusicoccin or the quasi‐ionophore gramicidin‐D on Rb+transport in intact barley seedlings (Hordeum vulgarecv Morex) was studied. Fusicoccin (1 μM) or gramlcidin‐D (3.2 μM) were added to absorption solutions which contained 0.1 mM RbCl and 0.5 mM CaSO4, and the Rb+content of roots and shoots determined over a 24 hour period. Roots of fusicoccin‐treated seedlings contained greater amounts of Rb+throughout the entire course of the experiment, and roots of gramlcidin‐D treated seedlings contained greater amounts of Rb+for the first 10 hours but contained smaller amounts of Rb+for the rest of the experiment when compared with control seedlings. However, shoots of seedlings treated with fusicoccin or gramicidin‐D contained smaller amounts of Rb+than the control seedlings throughout the entire course of the experiment. These results are discussed in terms of the interrelationships of the ion transport mechanisms which mediate the vectorial movement of ions from the absorption solution to the stelar apoplasm of the root.

ISSN:0190-4167    

DOI:10.1080/01904168609363539

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Sorghum [Sorghum bicolor(L.) Moench] plants grown in nutrient solutions, sand, and soil under greenhouse or growth chamber conditions developed a lower leaf “red‐speckling”; which was induced by phosphorus (P). As P in solution increased, the intensity of the “red‐speckling”; increased. Although the severity of “red‐speckling”; was not directly related to leaf P concentration, leaves with more severe symptoms had higher P concentrations. KS35, ‘Martin’, and ‘Plainsman’ developed severe symptoms, CK60‐Korgi, SC369–3‐1JB, and TX415 developed intermediate symptoms, and NB9040 developed no symptoms when grown at relatively low levels of P (10 to 20 umol per plant). Organic sources of P induced more severe “red‐speckling”; than inorganic sources. The severity of “red‐speckling”; induced by P compounds followed the sequence of gyceryl > ethyl ammonium = phenyl > potassium dihydrogen > calcium meta > calcium dibasic > calcium tribasic > ferric > calcium pyro = ferrous = aluminum phosphates. “Red‐speckling”; on young sorghum leaves may be caused by excess P. This excess or toxic P “red‐speckling”; occurred at P levels lower than had normally been considered or expected.

ISSN:0190-4167    

DOI:10.1080/01904168609363540

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Hail damage to an experiment that was being used to investigate nitrogen (N) nutrition of soybeans [Glycine max(L.) Merr.] with15N methodology provided a unique opportunity to study the effects of hail damage at the R3 stage of development on N uptake and partitioning through stage R5.8. Field plots were established on a silt loam soil (Typic Hapludol 1). Severely damaged (mean 72% leaf loss) and slightly damaged (mean 26% leaf loss) soybeans were compared for total reduced N and for15N concentration in leaflets, petioles, stems, roots, pod walls, and seeds during the 28 days following the hailstrom. The concentration of total N and of15N in all organs in both damage treatments declined significantly after the storm, but less in green leaflets (total N), and in green leaflets, green petioles, and pod walls (15N) of severely than of slightly damaged plants. Measurements on senesced leaflets and petioles showed that the concentration of15N also decreased to a greater extent than that of the total N in these organs. This differential loss of15N compared with total N suggests that the15N was in a form that was less refractory than was the bulk tissue N, and provides evidence of separate mobile pools of N in the plant. Nitrogen budgets were calculated to compare the loss of N and15N from abscising leaflets and petioles to the N accumulation of the damaged plants during podfill. These showed that loss from the leaflets and petioles contributed only7%of the total N accumulated by the plants between R3 and R5.8. This study has exemplified the usefulness of15N methodology in investigations of the nutrition and physiology of soybeans suffering leaf damage by hail.

ISSN:0190-4167    

DOI:10.1080/01904168609363541

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Assays based on acid phosphatase activity in plant tissue show promise for rapid diagnosis of phosphorus deficiency. This study was undertaken to evaluate a simple leaf disc assay for the detection of the phosphorus deficiency in maize leaves. Leaf discs were excised from 36 to 48 day old greenhouse‐grown maize plants which had been supplied with phosphate in solution culture at levels of 5, 25 or 75 yM and which had total P concentrations in the leaves ranging from 26 to 309 mmol kg‐1dry wt. For acid phosphatase activity determinations, discs were incubated 15 min. at 30°C with 5 mM paranitrophenol phosphate in a pH 5.8 acetate buffer. In plants which showed visual symptoms of P‐deficiency, acid phosphatase activity was 2 to 3 times as great as in P‐suf‐ficient plants. Results were inconsistent in plants which were only moderately P‐deficient. This study indicates that the leaf disc acid phosphatase assay should be useful in confirming visual diagnosis of acute phosphorus deficiency in maize, but may not be adequately sensitive to detect moderate P deficiency.

ISSN:0190-4167    

DOI:10.1080/01904168609363542

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0190-4167    

DOI:10.1080/01904168609363534

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor