摘要:

An experiment was conducted to study the effect of inoculation ofRhizobiumsuspension inAlbizia procera(Roxb.) Benth,Albizia lebbeck(L.) Benth, andLeucaena leucocephala(Lam.) De Wit. seedlings grown in sterilized and non‐sterilized soil media. Control treatments were maintained by non‐inoculation. Inoculation response was observed strong in sterilized and modest in non‐sterilized soil when compared to respective control treatments. Increase in height was found 105.07%, 63.42%, and 109% higher in sterilized soil and 52.1%, 68.6%, and 95.8% in non‐sterilized soil forAlbizia procera, Albizia lebbeck,andLeucaena leucocephala,respectively, after a period of 4 months. Nodule number increased up to 10.27 and 3.51 times inAlbizia procera,11.47 and 4.3 times inAlbizia lebbeck,and 7.22 and 2.9 times inLeucaena leucocephaladue to inoculation in sterilized and non‐sterilized soil media respectively. Significant increase in nodule dry weight and nitrogenase activity was also recorded in both sterilized and non‐sterilized soil for all the species tested. Nitrogenase activity per plant per hour was recorded 68.75,11.58, and 13 times higher in sterilized and 6.7,5.53, and 3.38 times higher in non‐sterilized soil over control for the species respectively after 4 months. In the tree species tested the inoculation ofRhizobiumshowed higher productivity, modulation and nitrogenase activity than control suggesting the idea that application ofRhizobiumsuspension greatly enhances plant growth, modulation, and nitrogenase activity.

ISSN:0190-4167    

DOI:10.1080/01904169909365694

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A greenhouse experiment involving four levels of boron (B) (0,5,10, and 20 mg kg−1) and three levels of zinc (Zn) (0,10, and 20 mg kg−1) was conducted on tomato (Lycopersicon esculentumMill., cv. ‘Lale'). Boron toxicity symptoms occurred at 10 to 20 mg kg−1B levels. These symptoms were partially alleviated in plants grown with applied Zn. Fresh and dry plant weights were strongly depressed by applied B. However, Zn treatments reduced the inhibitory effect of B on growth. Increased levels of B increased the concentrations of B in plant tissues to a greater extent in the absence of applied Zn. Both Zn and B treatments increased Zn concentration of the plants.

ISSN:0190-4167    

DOI:10.1080/01904169909365695

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

In soilless production systems, water quality can have a major impact on the growth of plants. It has become evident that moderately alkaline water is a problem for tobacco transplant growers in some regions of Kentucky. To determine the level of bicarbonate (HCO3−) alkalinity, which is detrimental to burley tobacco transplants, and to better understand the effect of calcium (Ca) and the interaction of HCO3−and Ca on the growth of burley tobacco transplants grown in a float system, three levels of CaCl2(25,75, and 125 mg L−1Ca++) in factorial combination with five levels of HCO3−(0, 122, 244, 366, and 488 mg HCO3−L−1) were tested in nutrient solution culture. Four‐week‐old burley tobacco (Nicotiana tabacumL. var. KY‐907) seedlings were transplanted to 18‐L containers filled with aerated Hoagland's solution with the different levels of calcium and HCO3−for two weeks. High HCC3−alkalinity caused root system damage and plant growth inhibition, but did not induce iron (Fe) chlorosis. A significantly lower concentration of Zinc (Zn) was measured in the shoots as HCO3−levels in solution increased. In the presence of high calcium, plant growth was not significantly improved. No significant interaction of HCO3−and Ca on growth or nutrient uptake was observed in this study.

ISSN:0190-4167    

DOI:10.1080/01904169909365696

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

High levels of bicarbonate (HCO3−) alkalinity have been shown to affect the growth and nutrient uptake of tobacco seedlings in solution culture. The objective of this study was to determine the effect of HCO3−on the nutrient uptake of burley tobacco seedlings grown in a float system. Float bays of a size to accommodate individual float trays were filled with 40 L of deionized water. A commercial 20–10–20 (20% N, 10% P2O5,20% K2O) water soluble fertilizer was added to give 100 mg N L−1. Sodium bicarbonate and calcium chloride were added to provide a factorial combination of 5 levels of HCO3−(0, 122, 244, 366, and 488 mg L−1) and three levels of calcium (Ca2+) (25, 50, and 75 mg L−1). Pelleted burley tobacco seed (var. KY 907) were sown into 200‐cell float trays filled with peat‐vermiculite medium. Plants in all treatments appeared normal. HCO3−alkalinity above 244 mg L−1limited the growth of tobacco seedlings. Total nitrogen (N), phosphorus (P) and potassium (K) concentration in the shoot portion of tobacco seedlings the lowest at 244 mg L−1HCO3−, as compared to lower or higher HCO3−levels. Calcium concentration in shoots increased with increased HCO3−, but zinc (Zn) decreased and magnesium (Mg) and iron (Fe) were not significantly changed. Added Ca2+had no significant effect on transplant growth. High nitrite‐N concentrations were observed in the float water solution three weeks after seeding. Nitrite‐N accumulation increased at high levels of HCO3−.Increased HCO3−alkalinity resulted in lower shoot nutrient concentrations, but the growth restriction due to HCO3−did not appear to be related to nutrient deficiency. However, transient levels of nitrite‐N may have been sufficiently high to result in stunting of the tobacco seedlings.

ISSN:0190-4167    

DOI:10.1080/01904169909365697

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

To evaluate the chance to reduce leaf NO3content and to increase capability to use NH4‐N even in the absence of NO3‐N in the nutrient solution, plants of two Apiaceae species, fennel(Foeniculum vulgareMiller var.azoricumMill. Thell.) and celery(Apium graveolensL. var.dulceMill. Pers.), and of one species of Chenopodiaceae, Swiss chard(Beta vulgarisL. var.vulgaris),were hydroponically grown in a growth chamber with three different NH4‐N: NO3‐N (NH4: NO3) ratios (100: 0,50: 50, and 0: 100), but with the same total N level (4 mM) for 14 days. Swiss chard growth was inhibited by NH4nutrition and reached the highest values with the NH4: NO3ratio 0: 100. For all the morphological and yield features analyzed, fennel and celery resulted to be quite unresponsive to nitrogen (N) chemical form. Water use efficiency increased in Swiss chard and decreased in fennel and celery with the increase of NO3‐N percentage in the nutrient solution. The dependency of N uptake rate on shoot increment per unit root was more conspicuous for Swiss chard than fennel and celery. All species took more NO3‐N than NH4‐N when N was administered in mixed form. In the best conditions of N nutrition, Swiss chard accumulated NO3in leaves in high concentration (3,809 mg kg"1fresh mass). On average, fennel and celery accumulated 564 mg NO3kg−1fresh mass with the ratio NH4: NO3100: 0 and showed that by using NH4produce having very low NO3content can be obtained. By increasing NO3‐N percentage in the nutrient solution; NO3leaf content of fennel and celery increased remarkably (7,802 mg kg−1fresh mass with the ratio N H4: NO30: 100).

ISSN:0190-4167    

DOI:10.1080/01904169909365698

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Plant mineral nutrient element status is an important factor influencing cotton (Gossypium hirsutumL.) growth, development, metabolism, and yield. A field study was conducted to determine changes in mineral nutrient element concentrations in leaves, bracts, and floral buds of field‐grown cotton plants during development of squares (floral bud with three bracts) as affected by fruiting position within the plant canopy. During square ontogeny, the nitrogen (N), phosphorous (P) and potassium (K) concentrations of sympodial leaves and floral bracts decreased, whereas the calcium (Ca) and magnesium (Mg) increased, and sulfur (S) concentration exhibited little change (leaves) or increased (bracts) with increasing square age. The N, P, Ca, and S concentrations in floral buds declined synchronously; K and Mg concentrations showed an increasing trend within the first 20 days, peaked at about 25‐day square age, and then sharply decreased three to five days before flowering. During square development, the effect of main‐stem node (MSN) and sympodial branch fruiting position in the plant canopy on mineral nutrient element concentrations of bracts was greater than on those of floral buds. Differences in the mineral nutrient element concentrations existed among the sympodial leaves, bracts, and floral buds. This study provides the patterns of mineral nutrient element concentrations in these plant tissues during the square development phase in relation to MSNs and branch fruiting positions in the cotton plant canopy.

ISSN:0190-4167    

DOI:10.1080/01904169909365699

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Potassium (K) is required in high doses by the banana(Musasp.) plant and interacts with other nutrient elements in which banana tissues are maintained under in vitro condition as a consequence modifications in the plant metabolism take place mainly in nitrogen (N) compounds, such as proteins, amino acids, and secondary compounds. When K is present in concentrations lower than that required, diamines such as putrescine and poliamines are formed. This metabolic disorder can also be correlated with the presence of different inorganic N forms, such as nitrate (NO3) and ammonium (NH4), and the ratios between both ions as well. In order to follow the physiological performance of the interrelationships, K/putrescine and of the NO3/NH4ratio in the tissue of banana vitroplantlets, shoot apex of two banana cvs. Nanica and Prata Ana were maintained in modified MS medium in the presence of six different doses of K: 5, 10, 15, 20, 25, and 30 mM. After the period of tissue proliferation the cultures were transferred to rooting media containing the same different K doses. Dry matter, K, putrescine, and spermidine contents and their accumulation were determined in the shoots and roots of the vitroplantlets and in the shoot apex of the expiant donor cultivar as well as the corresponding values for the whole vitroplantlets calculated. The data were statistically analyzed. The contents and accumulations of putrescine and spermidine in banana tissues were enhanced as K concentration decreased in the medium: four times (0.19% of the dry matter) for cv. Nanica and eight times (0.25% of the dry matter) for cv. Prata Ana. This behavior was not only related to the K depletion but to the NO3/NH4ratio as well.

ISSN:0190-4167    

DOI:10.1080/01904169909365700

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Grains of wheat were produced with differing zinc (Zn) or manganese (Mn) contents by culturing detached ears from anthesis onwards in solutions of four different concentrations of Zn or Mn (0.1,1.0,10, and 50 μM). After 20 days, ears were labeled with65Zn or54Mn at (i) the pretreatment concentrations of Zn or Mn, or (ii) at 10 μM Zn or Mn regardless of the pretreatment. Accumulation of Zn or Mn in the grain was greater as the pretreatment concentration of Zn or Mn increased from 1.0 to 10 μM, however, accumulation was less in ears cultured at 50 μM Zn or Mn. Accumulation of Mn in grain of different Mn status labeled at 10 μM Mn was similar in the 0.1,1.0, and 10 μM Mn pretreatments, but accumulation in the grain pretreated at 50 μM Mn was reduced. In contrast, accumulation of Zn in grains of different Zn status when labeled at 10 uM Zn was highest in ears pretreated at 10 μM Zn, but substantially lower in ears of a lower Zn status (those pretreated at 0.1 or 1.0 μM Zn) as well as in those pretreated at 50 μM Zn. These results suggest that Zn‐deficient grain was not a strong sink for Zn, while at high concentrations of solution Zn, a protective barrier exists preventing excessive accumulation of Zn in the grain. Proportionally more Zn was distributed to the inner pericarp and generally less to the endosperm, outer pericarp, and embryo as the Zn status of the grain increased. This work demonstrates that loading of Zn and Mn into, and distribution within, wheat grain is regulated by the nutritional status of the grain.

ISSN:0190-4167    

DOI:10.1080/01904169909365701

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

In highly weathered acid soils, low supply of phosphorus (P), a major plant nutrient, severely limits pasture establishment and production. Previous research indicated that inherent differences in efficiencies of P acquisition and use exist between tropical forage grasses and legumes when grown in acid soils. These differences in P acquisition between grasses and legumes may result from their ability to use sources of less available P from infertile acid soils. We tested this hypothesis by conducting a greenhouse study. The main objective was to determine differences in shoot and root growth responses between the grassBrachiaria dictyoneuraCIAT 6133 and the legumeArachis pintoiCIAT 17434 when grown under monoculture or in grass+legume association with different sources of inorganic and organic P. Two acid soils of contrasting texture (sandy or clay loam) were amended with different sources of P: di‐calcium phosphate (Ca‐P), aluminum phosphate (Al‐P),phyticacid(organic‐P), and cow manure (dung‐P). Except for A1‐P, which was applied at two rates (20 and 100 kg P ha−1), the sources were applied at 20 kg P ha−1. After 75 days of growth, shoot, and root biomass production, dry matter partitioning, leaf area production, total chlorophyll content in leaves, soluble protein in leaves, total root length, and proportion of legume roots in grass+legume association were determined. Greater differences for shoot and root growth characteristics were found between the grass and legume than between the two types of acid soil. Shoot biomass production per unit soil surface area of both species was higher with Ca‐P than with Al‐P, organic‐P, or dung‐P. With Ca‐P, the grass produced twice as much shoot and root biomass than did the legume. But, the legume responded to the sources of less available inorganic and organic P by extending its leaf area. Therefore, not only do wide differences exist between the grass and legume in their ability to grow on infertile acid soils amended with sources of relatively less available inorganic and organic P, but also the legume is better adapted to such soil conditions.

ISSN:0190-4167    

DOI:10.1080/01904169909365702

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Low phosphorus (P) supply is a major limitation to pasture establishment and production in highly weathered acid soils. Previous research showed that the forage legume,Arachis pintoi,was more efficient in acquiring P from infertile acid soils than the forage grass,Brachiaria dictyoneura.The main objective of the present study was to determine whether the higher P‐uptake efficiency (defined as “milligrams of P uptake in shoot biomass per unit root length") of the legume results from its greater ability to mobilize P from less available forms of phosphate (aluminum phosphate and organic P). The grass,Brachiaria dictyoneuraCIAT 6133, and the legume,Arachis pintoiCIAT 17434, were grown in the greenhouse for 75 days in monoculture or in association. They were planted in large plastic containers holding either one of two acid soils of contrasting texture (sandy or clay loam) and amended with different sources of P. Four sources of P were used: di‐calcium phosphate (Ca‐P), aluminum phosphate (Al‐P), phytic acid (organic‐P), and cow manure (dung‐P). Except for Al‐P, which was applied at two levels (20 and 100 kg P ha−1), the other sources were applied at 20 kg P ha−1. We found greater differences in P acquisition between the grass and legume than between the two types of acid soil. Acquisition of P by the legume was markedly greater than that of the grass, regardless of the source of P. The legume accessed 205 to 220% more sparingly soluble, inorganic P from soil compared to the grass. The relationship between shoot P uptake and root length showed that the legume roots acquired more P per unit root length than did the grass roots. The superior ability of the legume roots to acquire P from different P sources was associated with higher levels of inorganic P in roots. These results indicate that one reason for the success ofArachis pintoiin competing with aggressive grasses was its ability to acquire P from less available forms present in acid soils. This study also suggests that the measurement of inorganic‐P levels in roots may serve as a selection method to evaluate tropical forage legumes for their adaptation to less available P sources in P‐deficient acid soils.

ISSN:0190-4167    

DOI:10.1080/01904169909365703

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor