Showing papers in "Journal of Plant Nutrition in 2003"
TL;DR: Application of Si may be one of the available pathways to improve growth of this crop and increase its production in arid or semi arid areas.
Abstract: Plants of wheat growing in pots with silicon (Si) applied before sowing had greater plant height, leaf area, and dry materials compared to those without Si applied in well watering conditions. Drought stress was applied by withholding watering for 12 days from 26‐day old seedlings. In the stress conditions, plants growing in Si‐applied soil could maintain higher relative water content (RWC), water potential and leaf area compared to those without Si applied. Moreover, the Si applied plant dry materials were not significantly changed by drought while those of plants growing in pots without Si applied were significantly decreased, and this was mainly due to growth inhibition of the shoots. Drought stressed wheat growing in pots with Si applied had a significantly greater leaf weight ratio (LWR) and lower specific leaf area (SLA) compared to those of stressed plants in the absence of applied Si. This demonstrates that the leaves of stressed plants growing in pots with Si applied were thicker compare...
268 citations
TL;DR: Nitrogen use efficiency parameters are useful in differentiating lowland rice genotypes into efficient and non‐efficient responders to applied N, and could assist in identification of elite genotypes that could be used in breeding program to produce cultivars with high N use efficiency and capable of producing high yields.
Abstract: Rice is a staple food for more than 50% of the world's population. Based on land and water management practices, rice ecosystem is mainly divided into lowland, upland, and deep water or floating rice. However, major area and production at global level comes from lowland or flooded rice system. In rice growing regions nitrogen (N) is one of the most yield-limiting nutrients for rice production. Adaptation of cultivars or genotypes with high N use efficiency is a potential strategy in optimizing N requirements of crops, lowering the cost of production and reducing the environmental pollution. The objectives of this paper are to discuss rate and timing of N application, define N-use efficiency, discuss mechanisms involved for genotypic variation in N-use efficiency and present experimental evidence of genotypic variations in N-use efficiency in lowland rice. Evaluation methodology and criteria for screening N-use efficiency are also discussed. Significant variation in N use efficiency exists in lowland rice genotypes. Nitrogen use efficiency parameters (grain yield per unit of N uptake, grain yield per unit of N applied and recovery of applied N) are useful in differentiating lowland rice genotypes into efficient and non-efficient responders to applied N. Such an evaluation could assist in identification of elite genotypes that could be used in breeding program to produce cultivars with high N use efficiency and capable of producing high yields.
150 citations
TL;DR: In this paper, two long-term N fertility experiments were evaluated to examine temporal changes in nitrogen use efficiency (NUE) and their causes, and the average NUE for a 15-yr irrigated corn experiment was 30.6% at the lowest N input (90 kilograms N−1) and decreased to 18.3% at a rate of 270 kg N−ha−1−1.
Abstract: The efficiency with which fertilizer‐nitrogen (N) is transferred to grain‐N in cereals is usually less than 50% and averages 33% worldwide. Two long‐term N fertility experiments were evaluated to examine temporal changes in nitrogen use efficiency (NUE) and their causes. Averaged over 30‐yr, non‐irrigated winter wheat NUE was 49% at a 22.4 kg N ha−1 yr−1 rate and decreased to 34% at a rate of 112 kg N ha−1 yr−1. The average NUE for a 15‐yr irrigated corn experiment was 30.6% at the lowest N input (90 kg N ha−1) and decreased to 18.3% at a rate of 270 kg N ha−1 yr−1. Low NUE values are a result of excess N present in the soil–plant system. The extent to which N is present in excess is determined by the potential yield and how much of that yield will be supported by non‐fertilizer N, presumably mineralized from soil organic matter. For both experiments there was greater temporal variability in non‐fertilized (check‐plot) yields (CV of 31.4 for wheat and 34.3 for corn) than in plots where maximum yi...
142 citations
TL;DR: Plants grown on highly saline soils were severely affected where the dry weight was significantly lower than plants growing on moderately and low saline soils and the tiller number and the plant height were also lower under highly saline condition.
Abstract: Greenhouse experiment was conducted to evaluate the effect of arbuscular mycorrhizal fungi (AMF) on plant growth, and nutrient uptake in saline soils with different salt and phosphorus (P) levels. The following treatments were included in this experiment: (i) Soil A, with salt level of 16.6 dS m−1 and P level of 8.4 mg kg−1; (ii) Soil B, with salt level of 6.2 dS m−1 and P level of 17.5 mg kg−1; and (iii) Soil C, with salt level of 2.4 dS m−1 and P level of 6.5 mg kg−1. Soils received no (control) or 25 mg P kg−1 soil as triple super phosphate and were either not inoculated (control) or inoculated with a mixture of AM (AM1) and/or with Glomus intraradices (AM2). All pots were amended with 125 mg N kg−1 soil as ammonium sulfate. Barley (Hordeum vulgar L., cv. “ACSAD 6”) was grown for five weeks. Plants grown on highly saline soils were severely affected where the dry weight was significantly lower than plants growing on moderately and low saline soils. The tiller number and the plant height were a...
112 citations
TL;DR: In this article, the effects of supplementary calcium and potassium nitrate to strawberry (Fragaria × ananassa Duch) cultivars, Oso Grande and Camarosa in sand culture were investigated.
Abstract: A pot experiment was carried out with two strawberry (Fragaria × ananassa Duch) cultivars, Oso Grande and Camarosa in sand culture to investigate the effects of supplementary calcium and potassium nitrate to plants grown at high NaCl (35 mM) in complete nutrient solution supplied via roots. Treatments were (1) nutrient solution alone (C), (2) C + 5 mM Ca(NO3)2 + 5 mM KNO3 (C + CaN + KN), (3) nutrient solution + 35 mM NaCl (C + S), (4) C + S + 5 mM Ca(NO3)2 (C + S + CaN), (5) C + S + 5 mM KNO3 (C + S + KN), and (6) C + S + 5 mM Ca(NO3)2 + 5 mM KNO3 (C + S + CAN + KN). The plants grown at high NaCl had less dry matter, fruit yield, and chlorophyll content than those grown in normal nutrient solution for both cultivars. Both supplementary Ca(NO3)2 and KNO3 treatments significantly ameliorated the negative effects of salinity on plant growth and fruit yield. Treatment 4 (C + S + CaN) was slightly more effective in mitigating salt stress than treatment 5 (C + S + KN). However, neither of these was as ...
110 citations
TL;DR: In this paper, the solution to Fe chlorosis should be made by either improving the Fe uptake mechanism or increasing the amount of Fe in the soil solution, which can be determined by appropriate analytical methods such as HPLC.
Abstract: Iron chlorosis is a mineral disorder due to low Fe in the soil solution and the impaired plant uptake mechanism. These effects increased with high pH and bicarbonate buffer. The solution to Fe chlorosis should be made by either improving the Fe uptake mechanism or increasing the amount of Fe in the soil solution. Among Fe fertilizers, only the most stable chelates (EDDHA and analogous) are able to maintain Fe in the soil solution and transport it to the plant root. In commercial products with the same chelating agent, the efficacy depends on the purity and the presence of subproducts with complexing activity, that can be determined by appropriate analytical methods such as HPLC. In commercial products declaring 6% as Fe‐EDDHA, purity varied from 0.5% to 3.5% before 1999, but in 2002 products ranging 3–5.4% chelated Fe are common in the Spanish market. Fe‐o,p‐EDDHA, as a synthesis by‐product with unknown efficacy, is present in all Fe‐EDDHA formulations. Commercial Fe‐EDDHMA products also contain ...
106 citations
TL;DR: In this paper, the effects of foliar applications of calcium (Ca) and boron (B) on yield and fruit quality of “Elsanta” strawberries grown on a sandy loam soil with low status of available B.
Abstract: The aim of the experiment was to examine the effects of foliar applications of calcium (Ca) and boron (B) on yield and fruit quality of “Elsanta” strawberries grown on a sandy loam soil with low status of available B. The study was conducted in 1999–2000 at a commercial strawberry plantation in Central Poland. Cold‐stored strawberries were planted in 1998 at a spacing of 0.25 × 0.8 m. The following treatments were applied: (i) five sprays of Ca as CaCl2 at a rate of 1.5 kg Ca ha−1 spray−1 with addition of Tween 20 adjuvant at 0.1%; the first spray was performed at the petal fall stage and the next at 5‐day intervals; (ii) three sprays of B as Borvit material at a rate of 160 g B ha−1 spray−1 at the beginning of flowering and 5, and 10 days later; (iii) sprays of B and Ca as in the combination of (i) and (ii). Plants sprayed with water served as the control. Results showed that fruit and leaves from Ca‐treated plants had increased Ca concentrations. Sprays with B increased status of this microelem...
91 citations
TL;DR: The results show that mycorrhizal inoculation is an effective practice for improving crop production in P deficient soils and soil sterilization, and soil and crop management can help to get maximum benefit from indigenousMycorrhiza for sustainable P management.
Abstract: The Southeastern Anatolian Project (SAP, Turkish acronym GAP) is the largest irrigation and development project of Turkey covering about two million ha cultivated land. A number of field experiments in the region with different crops including maize, wheat, and cotton, have repeatedly shown that increased applications of phosphorus (P) fertilizers (i.e., from 0 kg P2O5 ha−1 up to 200 kg P2O5 ha−1) do not lead to any effects on crop yield in soils with low plant available P concentration. The aim of the research was to determine the potential effect of indigenous mycorrhiza and selected mycorrhiza species on plant growth and nutrient uptake under sterile and non‐sterile soil conditions. The preliminary results led us to study the effect of indigenous mycorrhizae potential on the growth of plants and P nutrition in a representative soil from the GAP under greenhouse conditions. Using inoculation of three different mycorrhizae species (Glomus caledonium, G. etunicatum, and G. mossea) maize plants we...
83 citations
TL;DR: In this paper, the effects of supplementary potassium phosphate applied to the root zone of salt-stressed plants were investigated, and the results showed an increase in dry matter, fruit yield, and chlorophyll concentrations.
Abstract: Bell pepper (Capsicum annuum cv. Urfa Isoto) and cucumber (Cucumis sativus cv. Beith Alpha F1) were grown in pots containing field soil to investigate the effects of supplementary potassium phosphate applied to the root zone of salt‐stressed plants. Treatments were (1) control: soil alone (C); (2) salt treatment: C plus 3.5 g NaCl kg−1 soil (C + S); and (3) supplementary potassium phosphate: C + S plus supplementary 136 or 272 mg KH2PO4 kg−1 soil (C + S + KP). Plants grown in saline treatment produced less dry matter, fruit yield, and chlorophyll than those in the control. Supplementary 136 or 272 mg KH2PO4 kg−1 soil resulted in increases in dry matter, fruit yield, and chlorophyll concentrations compared to salt‐stressed (C + S) treatment. Membrane permeability in leaf cells (as assessed by electrolyte leakage from leaves) was impaired by NaCl application. Supplementary KH2PO4 reduced electrolyte leakage especially at the higher rate. Sodium (Na) concentration in plant tissues increased in leave...
80 citations
TL;DR: The 41 B rootstock showed its lime‐tolerance by exhibiting little reduction of shoot length when grown in the calcareous soil as compared to the non‐calcareous one, while 3309 C growing in theCalCareous soil induced a dramatic shoot length reduction.
Abstract: The experiment considered Vitis vinifera L. cv. “Pinot blanc” clone VCR5 grafted on a lime‐susceptible (3309 C) and a lime‐tolerant (41 B) hybrid rootstock and grown in 45 L pots of a calcareous and a non‐calcareous soil. Each treatment included plants bearing clusters and plants without clusters; in the latter case the bunches were removed 15 days before blooming. During the third growth year, shoot length, leaf chlorophyll (Chl), and mineral element concentrations were recorded. At the end of the growing cycle the grapevines were divided into leaves, shoots, berries, cluster stems, trunk, roots, and dry matter and mineral element composition per organ were analyzed. The 41 B rootstock showed its lime‐tolerance by exhibiting little reduction of shoot length when grown in the calcareous soil as compared to the non‐calcareous one, while 3309 C growing in the calcareous soil induced a dramatic shoot length reduction. The rootstock also affected the leaf chl concentration according to the known degr...
72 citations
TL;DR: In conclusion, crops modify their root hair length as response to low K conditions and thereby maintain the uptake from sparingly soluble K sources.
Abstract: A decrease in the use of fertilizers and a decrease in soil fertility direct the research focus towards the ability of the crops to adapt to low potassium (K) conditions and to their ability to utilize sparingly soluble K sources. Pea (Pisum sativum), red clover (Trifolium pratense), lucerne (Medicago sativa L.), barley (Hordium vulgare), rye (Secale cerale), perennial ryegrass (Lolium perenne L.), and oilseed rape (Brassica napus oliefera) were grown in thin layers of soils to study their root morphological plasticity and ability to utilize different K pools at 26 and 60 mg exchangeable K kg−1 soil. The legumes (pea, red clover, lucerne) accumulated larger amounts of nitrogen but lower amounts of K than rye, ryegrass, barley, and oilseed rape. The differences in K accumulation correlated with root hair length (R 2 = 0.50). Rye had an outstanding root surface that in total as well as per unit root dry matter was twice that of the other crops. The ranking in decreasing order was rye, ryegrass, oil...
TL;DR: Results indicate that genetic differences exist in kernel‐Fe and ‐Zn concentrations and Fe bioavailability, which may be useful in biofortification intervention programs, but additional research is needed to determine the efficacy of iron‐rich maize varieties in alleviating iron deficiency in humans.
Abstract: Iron deficiency is estimated to affect over one‐half the world population. Improving the nutritional quality of staple food crops through breeding for high bioavailable iron represents a sustainable and cost effective approach to alleviating iron malnutrition. Forty‐nine late maturing tropical elite maize varieties were grown in a lattice design with two replications in three locations representing three agroecologies in West and Central Africa to identify varieties with high levels of kernel‐Fe. Bioavailable iron was assessed for some varieties selected for high Fe concentration in kernel and improved agronomic traits using an in vitro digestion/Caco‐2 cell model. Significant differences in kernel‐Fe and ‐zinc concentration were observed among varieties (P < 0.001). Kernel‐Fe levels ranged from 16.8 to 24.4 mg kg−1, while kernel‐Zn levels ranged from 16.5 to 24.6 mg kg−1. Environment did not have a significant effect on kernel‐iron and ‐zinc levels, but genotype by environment (G × E) interactio...
TL;DR: In this article, an on-farm experiment was conducted in Australia to investigate the cultivar variation in alfalfa (lucerne) (Medicago sativa L.) with respect to soil acidity and response to applied lime.
Abstract: Soil acidity is one of the limiting factors affecting the production and sustainability of pastures and crops in many parts of the world. An on‐farm experiment was conducted in Australia to investigate the cultivar variation in alfalfa (lucerne) (Medicago sativa L.) with respect to soil acidity and response to applied lime. The experimental site was a brown sandy clay loam with a soil pH of 4.8 (1:5 calcium chloride). Ten cultivars (Hunter River, Hunterfield, Sceptre, Aurora, Genesis, Aquarius, Venus, PL90, PL55, and breeding line Y8804) were tested at two levels of lime (0 and 2 t ha−1). Lime application significantly increased the root growth, nodulation, leaf retention, leaf to stem ratio, herbage yield, and crude protein content of alfalfa. Liming had a significant effect on elemental composition of alfalfa shoots. Aluminum (Al) concentration was reduced from 93 mg kg−1 DM in nil lime treatment to 45 mg kg−1 DM in +lime treatment. Similarly, manganese (Mn) and iron (Fe) shoot concentrations w...
TL;DR: Results obtained show that Cd remains predominantly located in the roots, which then seem to play the role of trap‐organs in the plant defense processes, in maintaining the glutamate pool in conditions where the need for NH4 + detoxification is increased by heavy metals.
Abstract: Young seedlings of tomato (Lycopersicon esculentum Mill.) grown on nitric medium and treated with different cadmium (Cd) concentrations (0–50 µM) were used. Results obtained show that Cd remains predominantly located in the roots, which then seem to play the role of trap‐organs. Increasing Cd concentration in the medium leads particularly to a decrease in NO3 − accumulation, together with decrease in the activities of nitrate reductase (NR), nitrite reductase (NiR), and glutamine synthetase (GS). On the other hand, stimulations were observed for ammonium accumulation, anabolitic activity of glutamate dehydrogenase (GDH) and protease activity. Contrarily, decreases were obtained for soluble protein contents and catabolitic activity of GDH. These results were discussed in relation to the hypothesis attributing to the mitochondrial enzyme NADH‐dependent GDH, an important role in the plant defense processes, in maintaining the glutamate pool in conditions where the need for NH4 + detoxification is in...
TL;DR: In this article, the influence of nitrogen (N) levels on N uptake, N remobilization in relation to grain yield and N concentration in stay-green versus early-senescing hybrids was evaluated.
Abstract: Maize (Zea mays L) is an important cereal crop with multiple purposes. Stay-green varieties have been considered a major progress in breeding for high yield. Nevertheless, few studies have been conducted to evaluate the influence of nitrogen (N) levels on N uptake, N remobilization in relation to grain yield and N concentration in stay-green versus early-senescing hybrids. Field studies were undertaken in P. R. China on an Ustochrepts soil to determine the effects of N levels and hybrid differing in leaf senescence on grain yield, N concentration, N uptake, N remobilization and residual N in vegetative tissues in 1996 and 1997. Results showed that ND108 (a stay-green hybrid) had greater yields than TK5 (an intermediate hybrid) and ZD120 (an early-senescening hybrid) under both high (225 kg N ha−1) and low N supply (0 in 1997 or 45 kg N ha−1 in 1996, respectively). ND108 took up more N than the two other hybrids. Grain N concentration of ND108 did not decrease significantly under low N compared to high N in 1997. However, in 1996 grain N concentration of ND108 decreased with reduced N supply, since post-silking N uptake was reduced by the shorter grain filling duration. N remobilization efficiency in vegetative tissue was higher in the early-senescening hybrid (ZD120) than in the stay-green hybrid (ND108). The N retained in the stover at harvest was much higher in ND108, which can lead to a deficit of soil N for the next crop when the stover is not returned to the field.
TL;DR: A number of organic compounds play a very important role in the hydrolytic reactions of iron and on the formation, nature, surface properties, reactivity, and transformation of Fe oxides as mentioned in this paper.
Abstract: A number of iron oxides (hematite, goethite, lepidocrocite, maghemite, and magnetite) or short‐range ordered precipitates (ferrihydrite) may be found in soil environments, but in the rhizosphere the presence of organic ligands released by plants (exudates) or microorganisms promote the formation of ferrihydrite. Iron ions are liberated into soil solution by acidic weathering of minerals and then precipitated either locally or after translocation in soil environments. Humic and fulvic acids as well as organic substances produced by plants and microorganisms are involved in the weathering of primary minerals. Organic compounds play a very important role in the hydrolytic reactions of iron and on the formation, nature, surface properties, reactivity, and transformation of Fe oxides. Organic substances present in the rhizosphere interact with Fe promoting the formation of ferrihydrite and organo‐mineral complexes. The solubility of Fe precipitation products is usually low. However, the formation of s...
TL;DR: Aur 6 can be considered a plant growth promoting rhizobacterium and is suitable for further field trials in other plants and in different production systems.
Abstract: In order to select potential Plant Growth Promoting Rhizobacteria (PGPRs), a selection of strains from the predominant genera in the rhizosphere of four lupine species, based on genetic divergence criteria, carried out in a previous study, yielded 11 Aureobacterium (Aur), four Cellulomonas (Cell), two Arthrobacter (Arth), two Pseudomonas (Ps), and six Bacillus (Bc) strains. Cell‐free culture filtrates of each bacterium were assayed for effects on germination, growth, and biological nitrogen fixation (BNF) of Lupinus albus L. cv. Multolupa seeds or seedlings. Four (Aur 6, Aur 9, Aur 11, and Cell 1) of the twenty‐five strains assayed promoted germination. Aureobacterium 6 and Aur 9 also increased root surface, total nitrogen content, and BNF. As a result of the screening, and considering all the variables studied, Aur 6 can be considered a plant growth promoting rhizobacterium and is suitable for further field trials in other plants and in different production systems.
TL;DR: In this paper, the effect of supplementary potassium nitrate (KNO3) on growth and yield of bell pepper (Capsicum annum cv. 11B 14) plants grown in containers under high rootzone salinity was investigated.
Abstract: The effect of supplementary potassium nitrate (KNO3) on growth and yield of bell pepper (Capsicum annum cv. 11B 14) plants grown in containers under high root‐zone salinity was investigated. Treatments were (1) control, soil only and (2) high salt treatment, as for control plus 3.5 g NaCl kg−1 soil. Above treatments were combined with or without either 0.5 or 1 g supplementary KNO3 kg−1 soil. Plants grown at high NaCl had significantly less dry matter, fruit yield, and chlorophyll than those in the control treatment. Supplementing the high salt soil with 0.5 and 1 g KNO3 kg−1 increased plant dry matter, fruit yield, and chlorophyll concentrations as compared to high salt treatment. Membrane permeability increased significantly with high NaCl application, but less so when supplementary KNO3 was applied. High NaCl resulted in plants with very leaky root systems as measured by high K efflux; rate of leakage was reduced by supplementary KNO3. These data suggest that NaCl status affect root membrane i...
TL;DR: In this article, the effects of mulch on plant growth, water use efficiency (WUE), fruit yield and quality, leaf relative water content, and macro-nutrition of Bell pepper grown at different water regimes and nitrogen levels were investigated.
Abstract: Bell pepper (Capsicum annuum L. cv. 11B 14) was grown under field conditions. The aim was to investigate the effects of mulch on plant growth, water use efficiency (WUE), fruit yield and quality, leaf relative water content, and macro‐nutrition of bell pepper grown at different water regimes and nitrogen levels. Treatments were (1) bare soil + water stressed (WS); (2) bare soil + well‐watered (C); and (3) black polyethylene mulch + water stressed (BPM + WS). Three different nitrogen (N) levels (70, 140, and 210 kg ha−1) were combined with the above treatments. Water stress was created by irrigating plants once every 5 days at 75% A pan (Epan) evaporation, compared with the control (C) that received 125% every other day. Water stress caused reductions in all parameters measured compared with unstressed (C) treatment. Using BPM covers improved fruit yield, fruit size, plant dry matter, relative water content, and chlorophyll concentrations in leaves in the stressed treatments and this treatment als...
TL;DR: Investigation of changes in ATPs and OASs activity, the first and the last enzyme of S assimilation pathway respectively, showed that S‐starvation increased the activity of both enzymes, but this effect disappeared in plants upon Fe deficiency suggesting that S metabolism is sensitive to Fe availability.
Abstract: The finding that the methionine is the sole precursor of the mugineic acid family phytosiderophores induced us to evaluate whether sulfur assimilation pathway has a role in plant response to Fe deficiency. Maize plants were grown for 10 days in nutrient solution (NS) containing 80 µM Fe in the presence (+S) or absence (−S) of sulfate. After removing the root extraplasmatic iron pool, half of the plants of each treatment (+S and −S) were transferred to a new Fe deficient NS (0.1 µM final Fe concentration) (−Fe). The remaining plants of each pre‐culture condition (+S and −S) were transferred to a new NS containing 80 µM Fe (+Fe). Leaves were collected 4 and 24 hours from the beginning of Fe deprivation period and used for chemical analysis and enzyme assays. Results showed that iron content in the leaves was lower in plants grown in S‐deficiency than in those grown in the presence of the macro‐nutrient. Iron deprivation produced an increase in the level of SH compounds in both nutritive conditions ...
TL;DR: Impaired photosynthesis and plant growth resulted in increased fruit abscission and changes in dry matter partitioning among plant tissues, which help explain effects of B deficiency on suppression of cotton growth and yield.
Abstract: Boron (B) deficiency is common in some cotton (Gossypium hirsutum L.) growing regions of the world. A better understanding of changes in the growth and physiological characteristics of cotton plants during the development of B deficiency will help us to define field diagnosis techniques and improve B fertilizer management recommendation. An experiment was conducted in a controlled‐environment growth chamber to determine effects of B deficiency during early vegetative growth on leaf photosynthesis, plant dry matter accumulation, photosynthetic assimilate partitioning, and other physiological parameters. Boron deficiency considerably decreased leaf net photosynthetic rate, plant height, leaf area, fruiting sites, and dry matter accumulation during squaring and fruiting. Depressed photosynthesis and plant growth (especially fruits and roots) resulted in increased fruit abscission and changes in dry matter partitioning among plant tissues. The results help explain effects of B deficiency on suppressi...
TL;DR: In this article, a trial was conducted to check soil effect on some physiological features such as leaf chlorophyll (Chl) concentration and gas exchange, whole canopy gas exchange and mineral nutrition, dry matter partitioning.
Abstract: Vitis vinifera L. cv Aurora grafted on S.O.4 (medium lime‐tolerance) rootstock was grown in pot with a high‐carbonate‐soil and a low‐carbonate‐soil. The aim of the trial was to check soil effect on some physiological features such as leaf chlorophyll (Chl) concentration and gas exchange, whole‐canopy gas exchange, mineral nutrition, dry matter partitioning, and technological grape parameters. Measurements for whole‐canopy gas exchange were taken using a custom‐built, flow‐through whole‐canopy gas exchange system set up to run continuous, automated, and simultaneous net carbon exchange rate (NCER) readings of four canopies. The most significant findings were: (a) high‐carbonate‐soil decreased leaf and whole canopy photosynthesis, grape yield, and total dry matter production; (b) high‐carbonate‐soil increased the distribution share of dry matter in the trunk and roots, as compared to the low‐carbonate‐soil, and decreased the share of dry matter in the clusters; and (c) lime‐stress conditions affect...
TL;DR: Growth and nutrient acquisition in sour orange (Citrus aurantium L.) were studied under salt stress in vitro as mentioned in this paper, where small reduction was obtained in growth (shoot length, shoot number, leaf number, and dry weight) when microshoots were directly exposed to NaCl stress from 0.0 to 150mM.
Abstract: Growth and nutrient acquisition in sour orange (Citrus aurantium L.) were studied under salt stress in vitro. Microshoots were transferred to Murashige and Skoog (MS) solid proliferation media containing 8.9 µM BA (6‐Benzyladenine) and 0.5 µM NAA (naphthaline acetic acid). Salinity was induced by incorporating different concentrations [0.0 (control), 50, 100, 150, 200, or 300 mM] of sodium chloride (NaCl) to the culture media. Microshoots were exposed to direct or gradual salinity shock. Slight reduction was obtained in growth (shoot length, shoot number, leaf number, and dry weight) when microshoots were directly exposed to NaCl stress from 0.0 to 150 mM. At 200 and 300 mM NaCl, growth parameters were adversly affected and microshoots died thereafter. Gradual NaCl shock was studied by transferring microshoots sequentialy every week to different NaCl concentraions (0.0, 50, 100, 150, 200, or 300 mM). Growth was monitored at each concentration until the end of the last week of incubation at 300 mM...
TL;DR: The Magruder plots are the oldest continuous soil fertility wheat research plots in the United States and are one of the longest continuous continuous fertility wheat plots in world as discussed by the authors. But they are not suitable for crop rotation.
Abstract: The Magruder plots are the oldest continuous soil fertility wheat research plots in the Great Plains region, and are one of the oldest continuous soil fertility wheat plots in the world. They were initiated in 1892 by Alexander C. Magruder who was interested in the productivity of native prairie soils when sown continuously to winter wheat. This study reports on a simple estimate of nitrogen (N) balance in the Magruder plots, accounting for N applied, N removed in the grain, plant N loss, denitrification, non‐symbiotic N fixation, nitrate (NO3 −) leaching, N applied in the rainfall, estimated total soil N (0–30 cm) at the beginning of the experiment and that measured in 2001. In the Manure plots, total soil N decreased from 6890 kg N ha−1 in the surface 0–30 cm in 1892, to 3198 kg N ha−1 in 2002. In the Check plots (no nutrients applied for 109 years) only 2411 kg N ha−1 or 35% of the original total soil organic N remains. Nitrogen removed in the grain averaged 38.4 kg N ha−1 yr−1 and N additions...
TL;DR: Investigation of Phosphorus–Zn interactions in two barley cultivars showed that the genotypic difference between the two cultivars in P uptake efficiency can be altered by Zn–P interactions, and that total Zn uptake by Sahara was higher than Clipper irrespective of P supply.
Abstract: Phosphorus (P)–zinc (Zn) interactions in two barley cultivars (Clipper and Sahara) differing in P and Zn efficiencies were investigated in a pot experiment carried out in a growth chamber. A highly calcareous field soil from a semi‐arid region of South Australia was used. Five levels of P addition and three levels of Zn addition were used. Plants were harvested five weeks after emergence. Increase in P supply significantly increased plant shoot biomass and tissue P concentrations in both cultivars, indicating that the soil used is P deficient. Zinc additions with low P additions caused slight decreases in plant biomass. However, Zn addition did increase plant growth when higher levels of P were applied demonstrating the importance of the balance Zn and P supply. Results showed that the genotypic difference between the two cultivars in P uptake efficiency (specific P uptake, SPU) can be altered by Zn–P interactions, and that total Zn uptake by Sahara was higher than Clipper irrespective of P suppl...
TL;DR: In this article, the effects of Fe limitation and bicarbonate addition to the nutrient medium on the organic acid metabolism were investigated in the root tips of various grapevine genotypes.
Abstract: The effects of Fe limitation and bicarbonate addition to the nutrient medium on the organic acid metabolism were investigated in the root tips of various grapevine genotypes. Cuttings of two limestone‐tolerant and two limestone‐susceptible Vitis genotypes were grown for four weeks in nutrient solutions containing 10 or 0.5 µM Fe. The effect of bicarbonate addition (5 mM) was studied for two of these genotypes. Compared to 10 µM, Fe limitation (0.5 µM) significantly increased citrate concentration in root tips after 2 weeks, and malate concentration after 4 weeks. When Fe limitation and bicarbonate addition were combined, citrate and malate concentrations were significantly increased after 2 weeks. Fe limitation or addition of 5 mM bicarbonate had a larger effect on citrate than on malate concentrations. Addition of 5 mM bicarbonate discriminated more clearly tolerant and susceptible genotypes than Fe limitation. High malate and citrate concentrations in the roots were associated to high PEPC acti...
TL;DR: Results suggest that LAI, in addition to NLV, should be considered in predicting tillers in rice crop.
Abstract: Relative tillering rate (RTR) increases linearly as leaf nitrogen concentration (NLV) increases in rice (Oryza sativa L.) plants. Leaf area index (LAI) has a negative effect on the emergence and survival of tillers. The objectives of this paper were to quantify the interactive effect of NLV and LAI on tillering in irrigated rice. Field experiments were conducted at Philippine Rice Research Institute (PRRI) and International Rice Research Institute (IRRI), Philippines during the dry seasons of 1995 and 1998. Two indica cultivars, IR72 and IR68284H, were subjected to various nitrogen (N) treatments. Number of tillers (including main stems), leaf area, and tissue N concentration were measured. The NLV explained a large part of variation in number of tillers m−2 among treatments. However, the residual, defined as the difference between observed and estimated number of tillers m−2, was negatively correlated with LAI (P < 0.01). When LAI was considered in addition to NLV, the model explained the variat...
TL;DR: In this paper, a survey study was initiated to determine the current S nutritional status of wheat plants in Ankara, Turkey in the cropping season of 1999-2000, and a greenhouse and field study were conducted during 2000-2001 on the effect of S on yield and yield components of bread and durum (Triticum aestivum L. cv. Bezostaja) wheat cultivars.
Abstract: Deficiency of sulfur (S) has been recognized as a limiting factor for crop production in many regions of the world. A survey study was initiated to determine the current S nutritional status of wheat plants in Ankara, Turkey in the cropping season of 1999–2000. Owing to the results of the survey study signing soil and plant S deficiency, a greenhouse and field study were conducted during 2000–2001 on the effect of S on yield and yield components of bread (Triticum aestivum L. cv. Bezostaja) and durum (Triticum durum L. cv. Kiziltan) wheat cultivars. According to the survey study results, more than 50% of the soil, plant straw, and grain samples contained lower S than the critical limits. Significant positive correlations were observed between total and extractable soil‐S (r = 0.4799), and also between both the total and extractable soil‐S and grain‐S (r = 0.3097 and r = 0.4162). Additionally significant positive correlation was observed between straw and grain‐S (r = 0.4500). Yield and some of th...
TL;DR: It is demonstrated that foliar application CaCl2, KH2PO4, or NH4NO3 improved heat tolerance of creeping bentgrass to some extent by slowing leaf senescence and maintaining photosynthetic activities.
Abstract: This study was designed to investigate physiological responses of creeping bentgrass (Agrostis palustris Huds.) to foliar application of nutrients under heat stress. “Penncross” plants were exposed...
TL;DR: Investigation at the protein, mRNA, and structural level showed that both systemic responses, involving transmission of long distance signals, and external nutritional signals, inducing localized responses, are involved in the complex control of iron homeostasis.
Abstract: Since iron is both an essential element as well as a potential toxin, it is a nutrient which on the one hand fulfils many important functions in plants but on the other can cause severe cell damage as a consequence of the formation of reactive hydroxyl radicals. Uptake of iron, its concentrations within particular tissues, and its subcellular distribution is therefore subject to careful control. In addition, the low bioavailability of iron in most soils necessitates the mobilization of sparingly soluble iron compounds. This has led to the evolution of concerted responses that assist in maintaining an adequate supply of iron for plant roots. These responses comprise morphological changes, such as the development of extra root hairs, formation of rhizodermal transfer cells, and induction of cluster roots, as well as induction of genes coding for enzymes involved in the mobilization and uptake of nutrients. Investigations at the protein, mRNA, and structural level showed that both systemic responses...