首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Abstract

The changes in the mineral nutrient content of the leaves of an evergreen species, the cork oak (Quercus suber L.), were investigated to assess the possibilities of a diagnosis of the mineral nutrition of this forest species. A comprehensive pattern of change in the leaf contents of N, P, and Ca was then put forward from the data obtained. Among the time intervals that are most favorable to analyses, the end of the vegetative rest period, in January, was investigated more precisely. The variation coefficients of the leaf contents measured tree by tree were determined for a number of nutrients (N, P, K, Ca, Mg, Fe, Cu, Zn, Mn, B, Al, and Cl). The foliar analyses carried out on 7‐ to 10‐month old leaves in stands submitted to various forest management practices led to the characterization of significant differences in P, Ca and Mn leaf contents in relation to the treatments applied.  相似文献   

2.
Abstract

Leaf analysis is a tool for effective fertilizer recommendations in fruit trees. To achieve this goal, a suitable leaf sampling method is a very important step. This study aimed to investigate suitable leaf position and leaf age to establish standardized leaf sampling method, which can collect representative leaf sample for leaf nutrient analysis in rose apple cultivar Tubtimjan. The experiment consisted of 3 leaf positions (1st, 2nd, and 3rd leaf position) from the growing tip and 1-8?months leaf age. The results indicated that the suitable leaf position to be the index leaves were 2nd and 3rd leaf position with 6–7?months old leaf age due to minimum variation of the leaf nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) concentrations. Moreover, the concentrations of N, P, and K tended to decrease, whereas, Ca, Mg, Fe, Cu, Mn, and Zn concentrations tended to increase as leaf age increased.  相似文献   

3.
Abstract

Responses of lime growth and chemical composition to salinity stress were evaluated on six‐month‐old lime seedlings raised under six salt levels with electrical conductivities (EC) ranging from 0.56–20 d‐Sm‐1 together with Soba natural saline soil with an intrinsic salinity of 7.2 d‐Sm‐1. Plantheight, number of leaves and branches, moisture content, and chlorophyll and nitrogen (N) contents were progressively reduced by high salt levels while leaf tip burn increased. Percentage total sugars (starch + soluble sugars) in leaf shoot and root tissues were higher in plants raised at higher (EC=16 and 20 d‐Sm‐1) salinity level and Soba saline soil treatments than in control plants or plants raised at low to intermediate salinity levels. Accumulated carbohydrates in the tissues of the salt‐stressed lime plants were viewed as compatible solutes needed for osmoregulation.  相似文献   

4.
Abstract

Nowadays, off-season leafy vegetables are generally characterized by low vitamin C (Vc) content and high nitrate accumulation due to low light intensity inner protected systems and high-level nitrogen supply. A glasshouse experiment was conducted to investigate the effects of three kinds of nitrogen-free solution treatments before harvest on Vc and nitrate contents in expanded leaf blades, expanded leaf petioles and old leaves of hydroponic lettuce. The results showed that using nitrogen-free solutions could decrease nitrate contents of expanded leaf blades, expanded leaf petioles and old leaves, also nitrate contents in above parts reduced increasingly with treatment time extending. In addition, three nitrogen-free solution treatments increased the Vc content of expanded leaf blades instead of expanded leaf petioles and old leaves. There were instead of significant positive correlations between nitrate contents but Vc contents of expanded leaf blades, expanded leaf petioles and old leaves. To conclude, nitrogen disruption treatment before harvest could effectively reduce nitrate contents in edible parts of lettuce, and also improve Vc content in expanded leaf blade.  相似文献   

5.
《Journal of plant nutrition》2013,36(12):2453-2468
Abstract

The top three leaves play important roles in biomass production and grain yield of rice (Oryza sativa L.) crop since the three leaves not only assimilate majority of carbon for grain filling during ripening phase, but also provide large proportion of remobilized‐nitrogen (N) for grain development during their senescence. The objectives of this study were to (a) compare senescence of the top three leaves and (b) compare the changes in N, chlorophyll, and ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco) contents of the top three leaves after their full expansion in field‐grown rice plants. When the basis of comparison among the top three leaves was plant age in terms of days after transplanting (DAT), senescence generally started earliest in ?3rd leaf, intermediate in ?2nd leaf, and latest in flag leaf. If the basis of comparison among the top three leaves was leaf age in terms of days after full leaf expansion (DAFE), it was not clear which leaf senesced earlier. Senescence rate was generally greatest in flag leaf, intermediate in ?2nd leaf, and smallest in ?3rd leaf. Ribulose‐1,5‐bisphosphate carboxylase/oxygenase content declined earlier, and at a faster rate than N and chlorophyll contents during the senescence of all top three leaves. Correlation analysis indicated a close relationship between N and chlorophyll contents. Ribulose‐1,5‐bisphosphate carboxylase/oxygenase content correlated with N content better than with chlorophyll content. The suitability of N, chlorophyll, and Rubisco contents for quantifying the leaf senescence of field‐grown rice plants is discussed.  相似文献   

6.
ABSTRACT

Variation in leaf nutrient composition with leaf age and position of leaflets was assessed for ‘Calcuttia’ and ‘Dehradun’ litchi cultivars under loam to sandy loam soils of north India. Leaf samples were collected from first to sixth pair of leaflets starting from the apex of terminal shoots to downward positions during December to May at monthly intervals at two locations for three successive years. The leaves were analyzed for N, P, K, Ca, Mg, Fe, Zn, Cu and Mn concentrations. In both litchi cultivars, leaf N, P, Zn and Cu contents remained more in young leaves; whereas, leaf Ca, Mg, Mn and Fe contents were observed higher in older leaves. Leaf K concentration exhibited inconsistent patterns; however, leaf K concentration in pair of leaflets on the shoot declined basipetal, being maximum in upper pair of leaflets and minimum in lower pair of leaflets. Levels of macro and micronutrients exhibited a degree of stability at second and third pair of leaflets when sampled during February–March. Leaf compositions differed significantly during active vegetative growth, flowering, and fruit development. The results revealed that 4–5 months old leaves from autumn flush at second and third pair of leaflets from the apex of terminal litchi shoots at the advent of panicle initiation (February–March) should be collected to assess the nutritional concentrations of litchi orchards under North India conditions.  相似文献   

7.
Abstract

The utilization of prebloom tissues to predict nutrition of apple (Malus domestica Borkh.) trees is limited. Therefore, the aim of this study was to assess the possible use of mineral analyses of the prebloom spur leaves and flowers to forecast the nutrition of ‘Idared’ apple trees in the mid-summer (based on the leaves from current-season shoots). The prebloom leaf concentrations of phosphorus, potassium, magnesium, boron and manganese were positively correlated with those in the summer leaves. The significant relationships between nitrogen, calcium, boron, and manganese in the flowers and those in the mid-summer leaves were also found. However, only the relationship between boron in the prebloom spur leaves and in the summer leaves was sufficiently strong. The calculated optimal range of boron in the prebloom spur leaves was 20–25?mg kg?1.  相似文献   

8.
9.
Abstract

Radlands Crimson strawberries were grown in a glasshouse with 7 rates of applied boron. Wood shavings mulches with different boron concentrations were also applied as separate treatments. Boron toxicity symptoms were produced in leaves by boron rates of 0.32 kg ha‐1 and greater on a soil containing 1.6 ug B g‐1 of hot water extractable boron. Concentrations greater than 123 μg B g‐1 in old leaves were associated with boron toxicity symptoms.

In the B rate experiment, soil boron concentrations greater than 1.9 μg B g‐1 soil were associated with leaf toxicity symptoms which increased in severity with increasing soil boron concentrations up to 4.1 μg B g‐1 soil. Wood shavings mulch containing 17 μg B g‐1 caused boron toxicity symptoms in older leaves whereas mulches containing less than 6 μg B g‐1 did not produce toxicity symptoms.  相似文献   

10.
Abstract

A field experiment was conducted at Al Malak Valley Farm, El-Sharkeya Governorate-Egypt (30°–51° N; 32°–53° E) using 15 years old productive mango (Mangifera indica L.) trees cv. Zebda. The experiment was repeated for two successive seasons (2014/2015) and (2015/2016). The trees were planted 8×8 meters apart in sandy soil under drip irrigation system using the Nile water. Treatments included three concentrations of boron (0.0, 250, 500?mg L?1) and three concentrations of nitrogen (1000, 1250, 1500?g nitrogen/tree/year). Boron was applied as foliar spray of boric acid and nitrogen was applied to the soil as ammonium sulfate. Treatments were arranged in a factorial Completely Randomized Block Design with three replicates for each treatment. Results show that boron application has improved mango tree nutritional status. Leaf nitrogen, phosphorus, potassium and boron concentrations significantly increased as the boron application rate increased. In addition, boron application resulted in significant increase in leaf total chlorophyll, total carbohydrates, total sugars, carbon/nitrogen (C/N) ratio and decrease in total phenol content. Boron showed higher impact than nitrogen on all tested parameters. The interaction treatment of 250?mg L?1 boron and 1500?g/tree nitrogen proved to be the best treatment.  相似文献   

11.
Abstract

A field crop of 3‐month old cabbages was sampled every 2 h from 0600 h until 2000 h. At each sampling, an upper, middle and lower leaf were taken from four plants, and their petiole nitrate status measured by three methods (a) “Merckoquant”; test strips (b) specific ion electrode on a fresh macerated extract and (c) the same electrode on an extract of oven dry tissue. All three methods led to similar conclusions: a. there were very big differences in concentration with leaf position, the middle leaf having the highest;

b. there were large concentration differences between plants, especially for the lower leaves;

c. the effect of time of day was not significant.

The test strips are capable of giving satisfactory results provided that sufficient plants are sampled, but values thus obtained for sap may be lower than for macerated fresh tissue, especially at the low end of the concentration range.  相似文献   

12.
Abstract

Because farmers use mixtures of leaves and stems as a soil amendment, data of leaves, stems, and a leaf/stem mixture of Indigofera constricta and Mucuna pruriens from a 20‐week litterbag study were analyzed to assess their decomposition, nutrient release, and possible interactions within mixtures. Decomposition and nitrogen (N)–release patterns were leaves≥mixtures≥stems, whereas phosphorus (P)–release patterns were the opposite (P<0.05). Leaves released 110–130 Kg N ha?1, and mixtures released 30% less. A similar ratio was obtained for P release. This suggests that nutrient release from leaf/stem mixtures is overestimated when only leaves are considered. Decomposition and nutrient‐release patterns of mixtures occasionally differed from estimated patterns by 2–5% (P<0.05), indicating that minor interactions took place. However, estimations based on the amount of released nutrients generally showed non significant interactions. This suggests that the impact of low‐magnitude interactions within mixtures during its decomposition on soil fertility are negligible when considering total nutrient release.  相似文献   

13.
Abstract

Six‐month‐old coffee plants were grown in the greenhouse in pots containing a Dark Red Latosol (Orthox), to study the effect of boron (B) and zinc (Zn) on growth and leaf content of these micronutrients. Boron was added at levels of 0, 1, 3, and 5 mg kg‐1, whereas Zn was added in proportions of 0, 5, 10, and 20 mg kg‐1. Boron application affected total dry matter, height and diameter of stem, length and number of plagiotropic branches, number of leaves, ratio between total leaf area and number of leaves (ULA), ratio between total leaf area and total dry matter (LAR), leaf moisture, and index of potential yield (IPY). The IPY, defined as the ratio of dry matter of developed flowering buds plus flowers to the dry matter of underdeveloped flower buds and flowers, proved to be the an excellent parameter to assess B levels. Leaf B, well correlated with IPY, varied from 50 to 60 mg kg‐1. Available B in soils, in nig kg‐1, ranged from (with the critical levels between parentheses): 0.2 to 0.3 (0.2), as determined in a saturation paste, 0.6 to 1.0 (0.9), as determined in a hot water extract, 0.9 to 1.3 (1.2), with monocalcium phosphate in acetic acid, 1.1 to 1.4 (1.3), by Mehlich 1 method, 2.1 to 2.4 (2.4), by 0.05N HC1, 2.2 to 2.4 (2.4), by 0.1N HCl. Zinc additions caused a decrease in growth when B supply was limiting. On the other hand, B had no effect on dry matter yield when Zn was not added. Adequate Zn soil levels in mg kg‐1 were 4.4, as determined by 0.05N HCl extraction, 4.2, by 0.1N HC1, 3.9, by Mehlich 1, 2.7, by EDTA extraction, and 2.1, in DTPA extracts. Leaf Zn, not affected by Zn additions, was between 12–14 mg kg‐1.  相似文献   

14.
Tissue testing is commonly used to determine nutrient status of crops, however, there may be differences in macro‐ and micronutrient content of main stem and branch leaves of plants. Macro‐ and micronutrient analyses of main stem and branch soybean (Glycine max [L] Merr.) leaves were performed separately to ascertain where foliar‐applied boron (B) was accumulating and to determine if other nutrients were partitioned differently between main stem and branch leaves in control plants and plants treated with foliar B. Foliar applications of 2.24 kg B/ha increased main stem leaf B content from 47 to 248 μg/g and caused leaf manganese (Mn) and aluminum (Al) content to decline. In a separate experiment, foliar applications of 1.12 kg B/ha onto soybean growing on a soil high in available Al increased B leaf content by over 50 μg/g and decreased leaf Al content by 100 μg/g. In other field experiments, foliar B applications of 0.90 kg/ha or more increased leaf B content in both main stem and branch leaves. Boron content was consistently higher in branch leaves than in main stem leaves. Branch leaves and seeds of soybean were higher in the phloem‐mobile elements potassium (K), magnesium (Mg), phosphorus (P), zinc (Zn), iron (Fe), and copper (Cu) than main stem leaves. With the exception of B, the relatively phloem‐immobile elements, calcium (Ca) and Mn were lower in branch leaves than in main stem leaves. The higher B content in branch leaves and seeds may indicate that B is more mobile in soybean than previously thought. The difference in macro‐ and micronutrient content of branch and main stem leaves and seeds should be noted when soybean leaves are being harvested for determination of macro‐ and micronutrient sufficiency, or when seeds are harvested for nutrient quality determinations.  相似文献   

15.
The first full and comprehensive attempt was made to standardize the time of sampling for the leaf nutrient diagnosis for Kinnow mandarin in North West semi arid zone of India by analyzing ten essential elements collected from spring cycle leaves. The samples were collected from February to January at monthly intervals for two years and the results revealed that the 6–7 month (August–September) old spring cycle leaves collected from terminal position of non- fruiting terminal is the best suitable time for foliar nutrient analysis in Kinnow mandarin grown in the North West India. In addition, the leaf nutrient concentrations of nitrogen and calcium of this period were best correlated and leaf phosphorus (P) and potassium (K) were least correlated with fruit yield by linear correlation analysis.  相似文献   

16.
  【目的】  对比大、中量养分短期缺乏下脐橙新、老叶片中11种必需元素含量及变化,并分析缺素导致的营养元素间的相互影响。  【方法】  以一年生枳砧纽荷尔脐橙幼苗为试材进行了砂培试验。以完全营养液为对照 (CK),设置缺氮 (?N)、缺磷 (?P)、缺钾 (?K)、缺钙 (?Ca)和缺镁 (?Mg)处理,测定不同处理脐橙叶片(老叶和新叶)生长指标及矿质元素含量。  【结果】  所有缺素处理均导致叶片叶绿素含量降低,生物量减少,以缺氮处理最为显著。缺氮降低了叶片N、Ca、Cu、Mo含量;缺磷降低了叶片P、K、Mo含量;缺钾降低了叶片K含量;缺钙降低了叶片N、Cu、Zn、Mo含量但增加了P含量;缺镁降低了叶片Ca、Mg、Zn、Mo含量但增加了K含量。以必需矿质元素为变量分别对各处理老叶和新叶进行主成分分析,老叶中第一主成分 (PC1)明显将缺钾处理与其他处理区分开,与对照相比,缺钾老叶离子组成变化为N (?3%)、P (+1%)、K (?71%)、Ca (+11%)、Mg (+39%)、B (+16%)、Mn (+11%)、Fe (+32%)、Cu (?7%)、Zn (+14%)、Mo (?63%);新叶中PC1明显将缺氮处理与其他处理区分开,缺氮新叶离子组成变化为N (?53%)、P (+8%)、K (+7%)、Ca (?14%)、Mg (+11%)、B (+55%)、Mn (+51%)、Fe (?14%)、Cu (?57%)、Zn (+4%)、Mo (?25%)。老叶和新叶中元素含量呈正相关的元素是N-Cu、N-Ca、Mg-Mn和Cu-Mo,呈负相关的是K-Zn。  【结论】  脐橙幼苗老叶对钾的短期缺乏反应最敏感,缺钾会显著降低老叶中K和Mo含量并增加Mg和Fe含量,而新叶对氮素的短期缺乏最敏感,缺氮显著降低新叶中N、Ca、Cu和Mo含量。短期缺少P、Ca和Mg对脐橙幼苗叶片中的养分含量影响较小。  相似文献   

17.
The effects of canopy manipulation and shading on crop quantity and quality as well as plant physiology in Vitis vinifera have already been studied by many authors while the plant nutritional status changes induced by such treatments present many unexplained aspects. Partial cluster and leaf removals were performed on Vitis vinifera L. cv. Cabernet Sauvignon at veraison (40% berries coloured) for two years to give four treatments: Control (C), Cluster Thinning (CT), Leaf Removal (LR), and Cluster Thinned + Leaf Removal (CT+LR) plots. At veraison, one half of these plots were shaded using a 50% shading net. The correlations between elemental contents of different organs showed that only potassium (K) in the leaves and stems were positively related, while for the other macro‐ and micro‐elements, no relationship or negative links were obtained. Shading needs only 14 days to modify the nitrogen (N) and phosphorus (P) in leaves. At harvest, N was depressed in leaves of cluster‐thinned vines and enhanced in leaf‐removed ones. Such changes are discussed on the basis of photosynthetic data which support the hypothesis that canopy manipulation involves modifications in both leaf biochemical and photochemical activities.  相似文献   

18.
Abstract

Broccoli (Brassica oleracea var italica cv. Premium Crop) plants were germinated in soil, transferred to vermiculite three weeks later and grown in the greenhouse, supplied continuously with boron concentrations ranging from 0.0 to 12.5 mg L‐1. At commercial maturity, the partitioning of nitrogen into soluble (nitrate, ammonium, amino acids) and insoluble components of the foliage (young and old leaves) and the florets was investigated. Both boron deficiency and toxicity increased the per cent soluble nitrogen, particularly as nitrate. Boron toxicity, but not deficiency, consistently affected the concentration and relative composition of amino acids. The actual nitrogen partitioning, including the relative amino acid composition, was dependent upon the developmental stage and of the plant organs, and whether boron was present in deficient or toxic levels. Together with information about the composition of transport fluids from a previous study, the data are interpreted as evidence for a reduction in the availability of carbon under conditions of boron stress.  相似文献   

19.
Abstract

Winter wheat was grown at five different experimental sites using various nutrient combinations of two nitrogen (N) and three calcium (Ca) doses. The three youngest leaves, including the flag leaf were sampled at anthesis together with the flag leaf post‐anthesis and the grain at final harvest. The leaves were weighed and their mineral nutrient contents analyzed and the grain was also weighed. Of the nine equations that were fitted the potential (log y versus log x) most consistently had the best correlation and, thus, best represents the relationships between leaf dry weights, while the inverse in both variables was best for estimating grain weight from leaf weight. The nutrient content of the leaves was related to leaf dry weight according to the following sequence of maximum R: ? (R = 0.703), potassium (K) (R = 0.580), Ca (R = 0.444), phosphorus (P) (R = 0.359), iron (Fe) (R = 0.291), and magnesium (Mg) (R = 0.290). The square‐root and the quadratic equations best reflected the maximum and minimum values for ? and K, respectively. Highly significant relationships between Ca and Mg, and leaf dry weight were less frequent. The leaf nutrients correlated with grain weight in the following order: Mg (R max = 0.521), ? (0.455), Ca (0.434), Fe (0.348), ? (0.346), ?n (0.339, and ? (0.323). Of these nutrients, only Ca affected grain weight according to a parabolic equation (quadratic or square‐root) while the rest were best fitted by logarithmic functions, both on X and Y or one variable separately and by a straight‐line in one instance.

The square‐root and the quadratic permit the calculation of the optimum concentration of nutrients, and thus, leaf nutritional diagnosis. The flag leaf at anthesis gives the most opportunities for this.  相似文献   

20.
Abstract

This investigation was conducted during two successive seasons (2014/2015) and (2015/2016) using 15?years old productive mango (Mangifera indica) trees cv. Zebda. The trees were grown at AlMalak Valley Farm, El-Sharkeya Governorate- Egypt (30–51° North; 32–53° East). Trees were planted 8?×?8 meter within and between rows in sandy soil under drip irrigation system using the Nile water. The objective of this study is to alleviate alternate bearing in cv. Zebda using mineral nutrients (nitrogen in the on year and boron in the off year). Treatments included three concentrations of nitrogen (1000, 1250, 1500?g/tree/year) and three concentrations of boron (0.0, 250, 500?mg L?1). Nitrogen was applied to the soil as ammonium sulfate and boron was applied as foliar spray of boric acid. The extra amount of nitrogen fertilizer (250 and 500?g N/tree) was applied at three installments in (May, June and July). Treatment was arranged in a factorial Completely Randomized Block Design with three replicates for each treatment. Results show that the on-year nitrogen fertilization significantly increased mango tree vegetative growth (number of shoot/branch, shoot length, shoot thickness, number of leaves/meter and leaf area) and yield. The average yield in the on year is 85.5?kg/tree at 1250?g N/tree but 67.4?Kilogram/tree at 1000?g N/tree (the control treatment). While in the off year boron foliar application resulted in a significant increase in flowering, initial fruit set, final fruit set and fruit yield. The average yield in the off year is 47?kg/tree at 250?mg L?1 boron but 9?kg/tree at 0.0?mg L?1 boron rate (the control treatment).The interaction treatment of 250?mg L?1 boron + 1500?g nitrogen/tree is the best treatment as it resulted in the highest values for all the tested parameters. The average yield of this treatment is 53.5?kg/tree. This treatment helps alleviate alternate bearing phenomenon by 41% and obtain the highest economic yield in the off-year, i.e. increased yield by 5.9 fold.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号