摘要:

Determinate soybean [Glycine max(L.) Merr.] has been characterized by few detailed nitrogen and phosphorous partitioning studies. Knowledge of the variation in N and P concentrations with plant part, nodal position, and plant age is needed for a better understanding of plant functions. In this field study, ‘Bragg’ soybean was grown on an Aquic Paleudult soil (series Goldsboro loamy sand). Plants were sampled at 10 to 14 day intervals beginning 44 days after planting (July 7) until harvest. Maximum observed N concentrations were 3.1, 2.8, 5.8, and 5.4% for stem internodes, petioles (+branches), leaf blades, and pods, respectively. Maximum observed P concentrations were 0.34, 0.48, 0.78, and 0.52 for the same respective plant parts. Nodal and temporal mean N and P concentrations varied considerably with plant age and nodal position in all plant parts. These data show that mean N and P concentrations in all four plant parts can vary several fold, depending upon plant age and nodal position for the sample. This suggests caution should be exercised in tissue sampling and interpretation of plant analysis. Concentrations of N and P generally decreased with time for stem internode, petioles (+branches), and leaf blades, but increased with time for pods. Except for N concentration in stem internodes, which increases with internode number, the N and P concentrations remain nearly constant throughout the growing season. The relationships provide insight for developing accurate plant models depicting N and P concentrations and translocations over time and among plant parts in determinate soybean.

ISSN:0190-4167    

DOI:10.1080/01904168909364016

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A rapid and simple nutrient addition technique was used for evaluating Al tolerance of six local upland rice (Oryza sativaL.) cultivars (BG35, BR21, DA25, DA26, DA14, and DA22) from Bangladesh and three IRRI rice, IR46, IR97, and IR45, cultivars from the Philippines. The plants were grown for 21 days with Al (0 μM, 140 μM, 280 μM or 560 μM) at pH 4.1. The roots were more affected by Al than the shoots. In rating cultivars for Al sensitivity, relative shoot weight (RSW) was found to be the best parameter due to the severe damage of the roots, irrespective of Al sensitivity. The cultivars were rated as Al tolerant (BG35, BR21, DA25, and DA26), mid‐tolerant (DA14, DA22, and IR46) and sensitive (IR97 and IR45) . More Al was retained in the roots of tolerant cultivars than in the mid‐tolerant or sensitive cultivars. In shoots, the Al concentration of tolerant cultivars was less than in the mid‐tolerant or in the sensitive cultivars and the inhibition of growth was proportional to Al concentration irrespective of Al tolerance. Therefore, the variation among cultivars in Al sensitivity could be related to the capacity of roots to retain Al from transport to the shoots.

ISSN:0190-4167    

DOI:10.1080/01904168909364017

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The effects of water deficit and excess Mn on leaf temperatures of two soybean cultivars were tested in greenhouse experiments on Mn toxic Loring soil. Cultivars used were Mn sensitive Forrest and Mn tolerant Lee. Water stress was created by withholding known amounts of water for a period of 12–24 hours. The untreated Loring soil produced Mn toxicity in Forrest but not in Lee. Hence, Mn was added as MnSO4‐H2O to induce toxicity in both cultivars; Mn treatments were 0 and 200 ug g‐1 for Forrest and 0 and 600 ug g‐1 for Lee. Both Mn and water stress increased leaf temperature. The interaction of water stress and Mn stress on leaf temperature could not be distinguished because both increased leaf temperature. Hence, under field conditions the detection of Mn induced leaf temperature change requires that water stress effects be eliminated. However, the effects of water stress on leaf temperature alone would be useful in assessing drought damage to crops. Since leaf temperature differences can be detected by remote sensing techniques, the results of this experiment will assist in the interpretation of remote sensing data.

ISSN:0190-4167    

DOI:10.1080/01904168909364018

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Phosphorus deficiency is one of the Important growth limiting factors in crop production in many regions of the world. The objective of this study was to evaluate responses of alfalfa (MedicagosativaL.), red clover (Trifoilum pratenseL.), common bean (Phaseolus vulgarisL.), wheat (Triticum aestivumL.) and rice (Oryza sativaL.) to concentrations of P in nutrient solution. The P treatments applied were 5, 50, 100, 200 and 400 μM P. All crop species significantly responded to an increase in external P concentrations. The optimum P concentration for maximum growth varied with crop species, but it was higher for legumes than for cereals. Rice needs minimum as red clover maximum P concentration for maximum growth in nutrient solution as compared to other crops species. Concentrations of K, Zn and Mn were significantly affected in all crop species with P addition. Suggesting positive effects of P in ameliorating Mn toxicity if this element is present in growth medium. Increasing concentrations of P in growth medium produce negative effect on K and Zn nutrition. Growth parameters and plant nutrients concentration and uptake correlation studies showed that legumes are more responsive to P fertilization as compared to cereals.

ISSN:0190-4167    

DOI:10.1080/01904168909364019

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Euonymus kiautschovicaLoes. ‘Sieboldiana’ plants were grown in small‐volume (450 cm3) or large‐volume (13,500 cm3) plastic containers in the greenhouse in a medium containing sandy loam, perlite, and compost and harvested at 4‐week intervals from the time of planting until 20 weeks. Plants were irrigated with a nutrient solution 3x ‐ 5x daily to prevent water and nutrient stress. After 8 weeks, leaf number, leaf area, and shoot length of lateral shoots from plants grown in small‐volume containers were significantly less than those of plants grown in large‐volume containers for both lateral shoots and the total plant. These differences persisted for the next 12 weeks. There were no differences, however, in shoot length, leaf number, or leaf area of the main shoot of plants grown in large or small‐volume containers, even after 20 weeks of root restriction. Thus, the reduction in overall growth of root‐restricted plants could be attributed almost entirely to a reduction in growth of the lateral buds. These findings have important implications for researchers and growers involved in container culture, where root confinement frequently occurs.

ISSN:0190-4167    

DOI:10.1080/01904168909364020

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Soybean(Glycine max(L.) Merrill) plants grown under normal nutrient conditions remobilize a high percentage of the total P absorbed from leaves to developing seeds. This study was conducted to determine the effect of P nutrition on dry matter production and P accumulation, distribution and remobilization during reproduction in soybean. Williams 82 soybeans were established in hydroponic culture in the greenhouse at four levels of P (0.45 mM, 0.20 mM, 0.10 mM or 0.05 mM) and harvested four times during reproductive growth. Dry matter production and P accumulation were reduced in the 0.05 mM P treatment to levels that were 10% of the 0.45 mM P treatment. The proportion of total plant P retained by nodules of low P plants was greater than that retained by nodules of high P plants (8.9% vs 4.2%). The 0.05 mM P plants partitioned a greater percentage of their P to seeds (74% vs 63%) than did the 0.45 mM P plants. Remobilization of P began in the 0.05 mM P plants earlier than in plants grown with 0.45 mM P. Restriction of P supply resulted in a greater percentage of plant P being retained by roots and nodules, and also in an increased percentage of plant P remobilized to the seed. Increased P remobilization indicates the importance of P in the life cycle of the plant. Increased P retention by nodules suggests that root nodule bacteroids exert demands on P irrespective of plant P status.

ISSN:0190-4167    

DOI:10.1080/01904168909364021

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Soybean(Glycine max(L.) Merrill) plants normally abort a high percentage of flowers and pods. This study was conducted to determine the effect of P nutrition on flower and pod abscission in soybean. Williams 82 soybeans were established in hydroponic culture in the greenhouse at four levels of P (0.45 mM, 0.20 mM, 0.10 mM or 0.05 mM), and main stem flowers and pods were counted every two days from flowering to maturity. The two highest P treatments had similar flower production, pod production, pod abortion, seed weight and seeds per pod, but the 0.20 mM P treatment had 20% lower dry matter production and 19% lower seed yield. At P supplies of 0.10 or 0.05 mM, flower production, pod production, flowers per node, pods per node, seed yield, seed number and weight per seed were less (P < 0.05) than at 0.20 mM. Flowers produced per main stem node and seeds per pod were largely unaffected by limited P. Plants supplied 0.10 or 0.05 mM P aborted more flowers and pods than did those supplied 0.45 or 0.20 mM P. At P supply of 0.05 mM, flower, pod and total abortion was 80%, 49% and 90%, respectively. Flower and pod production were 50% and 78% less, while plant dry weight, seed yield and weight per seed were 83%, 90% and 23% less, respectively for the 0.05 mM P treatment compared to control. The data indicate that the primary effect of limited P on reproductive growth of soybean is to increase flower and pod abortion.

ISSN:0190-4167    

DOI:10.1080/01904168909364022

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Plant analysis has been used to evaluate the nutritional status of many crops for diagnostic and corrective purposes. This study was initiated to establish critical nitrogen (N) plant tissue levels using midrib NO3‐N concentration for cabbage (Brassica oleraceaL., capitata group) during the growing season. Tissue samples for nitrate analysis were taken from cabbage plants over a period of four growing seasons beginning at the 4 to 6 leaf stage of growth and biweekly through pre‐harvest. The midrib from the most recently full sized leaf was sampled for NO3‐N concentration determination.

ISSN:0190-4167    

DOI:10.1080/01904168909364023

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Circumstantial evidence exists for non‐N‐mineral element transfer in legume‐grass associations. Three experiments were conducted in an effort to directly demonstrate transfer of a non‐N‐mineral element in alfalfa (Medicago sativaL.)‐maize (Zea maysL.) and alfalfa‐grain sorghum (Sorghum vulgarePers.) associations in two rooting media. Associations were established in double‐tube apparatus so that a single alfalfa plant was rooted in media of top‐ and bottom‐tubes, while an associated grass plant was rooted exclusively in the top‐tube (Intact treatment). Severed treatments (the control) were identical to the Intact treatments except the alfalfa roots in an air gap between the top‐and bottom‐tubes were excised.

ISSN:0190-4167    

DOI:10.1080/01904168909364024

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0190-4167    

DOI:10.1080/01904168909364015

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor