阿月浑子叶片矿质营养质量分数的季节变化

对引自美国、以色列和伊朗的3个阿月浑子品种的成年树在生长过程中的叶片营养元素(N、P、K、Ca、Mg、Mn、Cu、Fe)质量分数进行测定分析,结果表明,3个阿月浑子品种叶片矿质营养元素质量分数季节变化规律一致,从5月到9月,随叶龄的增加,N质量分数逐渐下降,Ca、Mg、Mn、K质量分数逐渐递增,其中Ca增加3倍,最为明显,而P、Cu、Fe质量分数变化不显著;7月中下旬营养元素质量分数相对稳定,为阿月浑子营养诊断的最佳采样时期;试验地总盐量在0～20cm和20～40cm土层分别为666.6mg·kg-1和900mg·kg-1,为强碱性土壤,导致阿月浑子P、Fe亏缺,叶片缺素症状明显,由于灌溉水含盐量高达2670mg·kg-1,到坚果成熟期部分叶片盐害症状明显,叶片中的Cu质量分数相对较高,但未发现明显的Cu害症状;阿月浑子叶片各营养元素质量分数的相关分析表明,不同元素间存在一定的相关性,其中N和Ca质量分数存在极显著的负相关关系,Mg和Cu质量分数存在极显著的正相关关系。     

Vector analysis in the study of the nutritional status of Philodendron cultivated in compost-based media

Compost (CP) made from 70% ligno-cellulosic compounds and 30% sewage sludge was studied as a component of growing media in a 6-month Philodendron cultivation. CP's agronomic viability was evaluated via four plant-growth media containing 25–50–75–100% CP and white sphagnum peat (WP) in comparison to a commercial substrate with white and black peat. Plant nutrition conditions were investigated by determining macro- (TKN, P, K, Ca, Mg and micronutrients (Mn, Fe, Cu, Zn, Na) and heavy metals (Ni, Cd, Cr, Pb) in roots and shoot tissues. Data were compared by vector analysis against control. Even if no leaf injuries were visible after 6-months’ growth, a CP ratio of up to 50% caused growth depression of canopy tissues, as attested by the 37 and 36% reduction in total leaf dry weight and leaf area, respectively. Root growth decline was also notable at 25% CP, where 38% root dry weight reduction implied a significant increase (46%) in shoot–root dry weight ratio. The investigation on nutrient tissue content showed high accumulation of Ni, Fe, Cr, Zn, Cd, Mn, Mg and P in roots; Mg appeared related to K deficiency. Above-ground nutritional status showed a severe lack of P, Mg and Mn. Vector analysis suggests the sewage sludge CP in Philodendron pot cultivation produces many such effects like direct toxic action and antagonistic action, resulting in a general nutrient imbalance in plants.     

Variation in nutrition along time and relative chlorophyll content of Leucospermum cordifolium cv. ‘High Gold’, and their relationship with chlorotic sypmptoms

Foliar samples, SPAD-502 measurements (both along the growing season), and soil samples were taken from protea plants (Leucospermum cordifolium), cultivar ‘High Gold’ cultivated in six commercial plantations of La Palma Island (Canarian Archipelago). Soil data (pH, available P, Ca, Mg, K and Na, and EC) ranged within normal levels for proteas, though O.M. was high. Drainage decreased the potential problem that could be caused by the high clay content of the soils. Leaves showed high concentrations of N, K, Mg, and Na, while Ca and Cu were normal. On the other hand, Fe and Zn presented some low foliar levels, while Mn values fluctuated depending upon the different plantations. N contents were higher in spring, and those of K, Ca, Mg, and Na increased with time. Relative chlorophyll contents (SPAD-502 measurements) were compared with macro- (N, P, Na, K, Ca, Mg) and micro- (Cu, Fe, Mn, Zn) foliar levels. Results showed no positive correlation between leaf chlorophyll and N content. Higher leaf N concentrations were observed in chlorophyll deficient than chlorophyll sufficient leaves at one site and vice versa at another site. In contrast, lower Mn, Fe and Ca concentrations, the last corresponding with higher ratios of N/Ca were observed in chlorophyll deficient than chlorophyll sufficient leaves at several sites. It is concluded that amendment of soils with Mn, Fe and Ca may prevent the development of chlorophyll deficiency symptoms, associated with diminished photosynthetic capacity, in this important commercial cultivar.     

γ–氨基丁酸对低氧胁迫下甜瓜幼苗氮代谢及矿质元素含量的影响

 以甜瓜‘西域1号’为材料,采用营养液水培方法,研究了低氧胁迫下外源γ–氨基丁酸（GABA）对幼苗根系无机氮代谢及矿质元素含量的影响。试验结果表明,低氧胁迫下甜瓜根系中硝酸还原酶（NR）、亚硝酸还原酶（NiR）活性显著提高,硝态氮（NO₃^--N）、亚硝态氮（NO₂^--N）、铵态氮（NH₄⁺-N）以及谷氨酸、氨基酸、总氮含量显著增加,而可溶性蛋白含量显著降低,同时K⁺、Ca²⁺、Mg²⁺、Zn含量显著降低,Mn、Fe、Cu含量大幅提高,根系生长受到严重抑制;低氧胁迫下添加外源GABA处理的甜瓜根系中NO₃^--N、NO₂^--N、NH₄⁺-N、谷氨酸、氨基酸、可溶性蛋白质、总氮、K⁺、Ca²⁺、Mg²⁺、Zn含量以及NR、NiR活性显著高于低氧胁迫处理,而Mn、Fe、Cu含量显著降低,缓解了低氧胁迫对根系生长的抑制;低氧胁迫下同时添加GABA和钨酸钠处理的根系NR活性显著降低,同时NiR活性和NO₃^--N、NH₄⁺-N、谷氨酸、氨基酸、可溶性蛋白质、总氮含量和根系干质量均显著降低。说明低氧胁迫下外源GABA可以通过诱导NR活性的提高促进硝酸盐的吸收和转化,通过提高K⁺、Ca²⁺、Mg²⁺、Zn的吸收和减少Mn、Fe、Cu的吸收,缓解低氧胁迫甜瓜根系的伤害。     

植物生长过程中对营养元素吸收情况分析研究

选用三倍体毛白杨的幼苗作为培养材料, 选用MS培养基在组培室进行培养,从植物培养15 d开始每隔5d取样1次,进行培养基中K、Ca、Mg、Zn 、Fe、Mn元素的含量测定,以确定在这段时期内植物对上述6种元素的吸收程度.结果表明:Zn、Mn、Ca、Mg在培养物的生长过程中吸收比较均匀,K在早期吸收强烈,后期几乎不吸收.Fe在早期以及后期吸收量比较大,中期吸收量比较少.     

Effects of root inoculation of plant growth promoting rhizobacteria (PGPR) on yield,growth and nutrient element contents of leaves of apple

From 2002 to 2006, plant growth promoting effects of Bacillus M3, Bacillus OSU-142 and Microbacterium FS01 were tested alone or in combination on apple (Malus domestica L.) cv. Granny Smith in terms of yield, growth and nutrient composition of leaves in the province of Malatya, Turkey. The presence of M3 and/or OSU-142 and/or FS01 combinations stimulated plant growth and resulted in significant yield increases in Granny Smith. Root inoculation of PGPR strains significantly increased cumulative yield (26.0–88.0%), fruit weight (13.9–25.5%), shoot length (16.4–29.6%) and shoot diameter (15.9–18.4%) compared with the control. In addition, all nutrient element contents (N, P, K, Mg, Ca, Fe, Mn and Zn) investigated in Granny Smith, except Mg was significantly affected by bacterial applications compared with the control. The highest N content (3.38%) was obtained from OSU-142 + FS01 application. Phosphorus contents of leaves of Granny Smith increased from 0.29% in the control to 0.42, 0.37, 0.36, 0.36 and 0.35% by M3, M3 + FS01, M3 + OSU-142, OSU-142 and M3 + OSU-142 + FS01 application, respectively. All bacterial applications significantly increased Ca content of leaves. The highest K, Fe, Mn, Cu and Zn content of leaves were obtained from OSU-142, M3, FS01, M3 and M3 + FS01 applications, respectively. The results of this study suggest that Bacillus M3 and/or OSU-142 and/or Microbacterium FS01 in combination have the potential to increase the yield, growth and nutrition of apple trees.     

不同叶面肥处理对日光温室“87-1”葡萄生长发育的影响

以日光温室"87-1"葡萄为试材,设置叶面喷施氨基酸系列肥(AA-S)、氨基酸硒肥(AA-Se)、氨基酸硒肥+微量元素(AA-Se+T)和喷清水(CK)4个处理,研究了不同叶面肥处理对日光温室葡萄生长发育的影响,以期为日光温室葡萄叶面肥的选择及改良研发提供参考依据。结果表明:与CK相比,喷施叶面肥处理显著提高了葡萄的成花枝率、结果系数、比叶干质量、叶绿素b含量、叶绿素总含量和成熟期果实的N、P、K、Ca、Mg、Fe、Cu、Mo等矿质元素含量,以及果实的可溶性固形物含量。其中,AA-Se+T处理的成花枝率、叶绿素a含量、叶绿素b含量、叶绿素总含量、类胡萝卜素含量、成熟期果实的N、P、K、Fe、Mn、B、Cu和Mo含量,以及可溶性固形物含量均显著高于AA-S处理和AA-Se处理,成熟期果实的Ca和Mg含量则以AA-S处理最高。Topsis综合评价分析,CI指数表现为AA-Se+T处理>AA-S处理>AA-Se处理>CK。综上所述,喷施叶面肥可以提高日光温室"87-1"葡萄的成花能力、叶片质量、果实矿质元素含量和果实品质,以AA-Se+T处理效果最佳。AA-S处理显著提高了成熟期果实的Ca、Mg含量,可用于解决果实缺钙问题和高钙果品的生产。     

喷施微肥对砂培韭菜生长及硝酸盐含量的影响

在日光温室内研究了高硝态氮营养环境下,分别喷施微量营养元素钼、锰、硼、铁、锌对砂培韭菜叶片硝酸盐含量及植株生长的影响。结果表明:叶面喷施钼或硼均可显著降低韭菜的硝酸盐含量,降幅达20.4%~32.4%,但未发现有提高韭菜生物量的作用;叶面喷施锰或铁均显著降低了春季韭菜的硝酸盐含量,降幅分别为14.7%和13.9%,且显著提高了韭菜植株的生物量,植株鲜重分别增加了17.6%和13.3%,干重增加了17.3%和18.1%;在秋冬季低温时期增施钼可提高韭菜叶绿素含量。     

三峡重庆库区甜橙叶片矿质营养丰缺状况调查

 为了解三峡重庆库区甜橙叶片矿质营养丰缺状况,2009年对库区5个甜橙主产县200个甜橙园4 ~ 6月龄营养性春梢叶片营养元素进行了分析测试。结果表明,三峡重庆库区甜橙叶片营养明显失衡,N和Fe含量很高,P、Zn和Mo比较适宜,K、Ca、Mg、Cu和Mn含量较低,而B含量严重不足。叶片N、P、K、Ca和Mg的平均含量分别为（27.34 ± 5.92）、（1.40 ± 0.21）、（11.00 ± 3.04）、（25.27 ± 8.53）和（3.34 ± 0.89）g · kg^-1,Fe、Cu、Mn、Zn、B和Mo的平均含量分别为（125.00 ± 40.55）、（5.38 ± 2.59）、（33.69 ± 6.33）、（34.30 ± 17.91）、（23.68 ± 14.24）和（0.79 ± 0.49）mg · kg^-1,且N和Fe处于高量及以上水平的比例分别为39.5%和53.0%,P、Zn和Mo在适宜范围的比例分别为75.5%、83.5%和70.5%,K、Mn和Mg处于低量水平的比例分别为50.3%、37.5%和20.0%,B、Ca、K、Cu在低量及以下水平的比例分别为76.5%、64.0%、57.3%和51.0%。库区大部分橘园叶片B含量严重不足,生产上需要重视补充B肥;同时生产上需根据甜橙叶片营养诊断结果,适量补充Ca肥和K肥,以满足柑橘营养平衡施肥。     

赣南不同土壤类型脐橙园叶片营养状况研究

从赣州市10个县(市、区)的沙质红壤、黏性红壤、紫色土和黄壤等131个枳砧纽荷尔脐橙园采样测定叶片营养元素含量,分析营养丰缺状况。结果显示,赣南脐橙园普遍存在叶片氮、钾偏高而镁、锌不足的问题。土壤类型对叶片氮、磷、钾、钙、镁、铁和锰含量有显著(P<0.05)影响:沙质红壤果园磷、铁更为丰富;黏性红壤果园氮含量最高,钾的过量程度和镁的缺乏程度都最轻;黄壤果园磷更丰富,钙更缺乏,锰最容易过量;紫色土果园氮、磷含量最低,钾易过量,钙较丰富,镁最缺乏,有部分pH值较高的果园植株缺铁。叶片硫、锌、铜、硼和钼在不同土壤类型的果园间差异不显著(P>0.05),但有相当比例的脐橙园叶片缺铜,少量果园叶片缺硼,大多数果园叶片硫含量适宜,所有果园叶片钼含量适宜。     

Impact of grafting and rootstock on nutrient-to-water uptake ratios during the first month after planting of hydroponically grown tomato

Tomato plants (cv. Primadonna F₁), non-grafted, self-grafted, or grafted onto the commercial rootstocks ‘He-man’ and ‘Maxifort’, were grown in recirculating nutrient solution. The uptake concentrations (UCs), i.e. mean nutrient-to-water uptake ratios of N, P, K, Ca, Mg, Fe, Mn, Zn, Cu, and B, were estimated based either on depletion from the nutrient solution or on accumulation in the plant biomass. Grafting onto both commercial rootstocks increased the total plant biomass. Hetero-grafting also increased the leaf N, Ca, and Cu concentrations but decreased those of Mg and Fe in comparison with self- and non-grafted plants. The mean UCs of N, Ca, and Cu were higher in plants grafted onto both commercial rootstocks in comparison with self- and non-grafted plants. However, hetero-grafting also raised the UCs of P, Fe, Mn, and B, because of an increased deposition of these nutrients to the roots in comparison with self-rooted plants. The method used to estimate the UCs, i.e. nutrient removal from the recirculating nutrient solution vs. nutrient recovery from plant biomass per volume unit of transpired water, resulted in similar values for N, Ca, Zn, and Cu, but had a significant impact on those of P, K, Mg, Fe, Mn, and B.     

Gas exchange and antioxidant response of sweet pepper to foliar urea spray as affected by ambient temperature

This paper analyses the effect of different air temperatures (10, 20 and 30 °C) on the response of sweet pepper plants (Capsicum annuum L. cv. Herminio) to foliar urea applications after growing plants for 20 day with and without nitrogen (N) applied to the growing substrate. Leaf CO₂ assimilation, chlorophyll fluorescence, root respiration, lipid peroxidation and antioxidative enzymes were analysed. Spraying plants with urea increased leaf CO₂ assimilation of N-deficient plants when applied at 20 or 30 °C, compared with non-sprayed plants. When plants were sprayed with urea at 10 °C chlorophyll fluorescence of leaves was similar to that of plants that were supplied with full N in the nutrient solution. Root respiration was not affected by urea sprays whilst leaf NO₃⁻ concentration was increased by urea but only when it was sprayed at 10 or 20 °C. Lipid peroxidation and ascorbate peroxidase in N-deficient plants were reduced significantly by urea sprays, especially when plants were sprayed at 20 °C with N-limitation in the growing substrate. This study shows that N-limitation in the growing substrate induces a temperature-dependant increase in the activities of antioxidant enzymes in leaves of pepper and applications of foliar urea can be optimised, when applied at the appropriate temperature, to partly replace the N supplied to the roots of sweet pepper.     

Influence of almond × peach hybrids rootstocks on flower and leaf mineral concentration,yield and vigour of two peach cultivars

Flower and foliar nutrient content of ‘Queen Giant’ and ‘Tebana’ peach [Prunus persica (L.) Batsch] on six almond × peach hybrids rootstocks (‘Adafuel’, ‘Adarcias’, ‘GF 677’, ‘Cadaman’, ‘Garnem’ and ‘Felinem’) were determined during one season. The mineral elements analysed were: N, P, K, Ca, Mg, Fe, Mn, Zn, Na and Cu. Leaf N concentration in ‘Queen Giant’ was the highest on ‘Cadaman’ and ‘GF 677’ and the lowest on ‘Adarcias’. The P, Fe and Zn concentrations in flowers and leaves were significantly correlated. The leaf chlorophyll concentration at 120 DAFB was positively correlated with Fe floral concentration and with K, Zn and Na leaf concentration, in ‘Queen Giant’, and with K and Mn leaf concentration, in ‘Tebana’. In ‘Queen Giant’, the greatest trunk cross-sectional area was exhibited with ‘Felinem’ and ‘Garnem’ and the lowest with ‘Adarcias’. In contrast, the greater yield efficiency was found on ‘Adarcias’. In ‘Queen Giant’, a negative correlation was found between yield efficiency and Ca in leaves and in flowers. A positive correlation was observed between tree vigour and flower Fe, flower Ca and leaf Ca concentration. Correlation was also found between yield efficiency and Mg in ‘Tebana’ flowers. In ‘Queen Giant’, ‘Felinem’ rootstock showed the weakest balanced nutritional values (ΣDOP index) compared with other rootstocks.     

Foliar application of chlorocholine chloride improves leaf mineral nutrition,antioxidant enzyme activity,and tuber yield of potato (Solanum tuberosum L.)

In southern China, potatoes (Solanum tuberosum L.) are grown in the late season and the crops are often subjected to low temperature stress particularly during the tuber bulking stage. Exogenous chlorocholine chloride (CCC) treatment has been found to improve crop performance under suboptimal growth conditions; however, the physiological mechanisms underlying the beneficial effects have not been fully understood. The objective of this study was to investigate the effects of CCC treatment on mineral nutrition, antioxidant enzyme system, and tuber yield of potato (cv. Zhongshu 3) under field conditions. The plants were foliar sprayed twice with 1.5, 2.0 and 2.5 g l⁻¹ CCC at 24 and 28 days after emergence (DAE), respectively; and plants without CCC treatment were serviced as control. Leaf samples were collected on 56 DAE for determination of mineral nutrition contents and antioxidant enzyme activity. Results showed that 1.5 and 2.0 g l⁻¹ CCC treatments significantly increased the contents of P, K, Ca, Mg, Fe, Mn, Zn and Cu in potato leaves. These treatments also increased superoxide dismutase (SOD), peroxidases (POD) and catalase (CAT) activities in the leaves. A positive linear relationship was found between SOD activity and the content of Fe + Mn + Zn + Cu. Tuber yield was significantly increased by CCC treatment. It is concluded that treatment with certain concentration of CCC (e.g. 1.5–2.0 g l⁻¹) improves mineral nutrition and SOD, POD and CAT activities in potato leaves; which might have contributed to the higher tuber yield of the crop grown under suboptimal conditions.     

Comparative effects of ultrasonic transducers on medium chemical content in a nutrient mist plant bioreactor

The objectives of this study were to evaluate the efficiency of ultrasonic transducers in a nutrient mist bioreactor by analyzing the chemical constituents (carbohydrates and inorganic elements) of the mists produced by ultrasonic transducers from a liquid sucrose-supplemented Murashige and Skoog (MS) medium. The ultrasonic transducer oscillation frequency with an input power of 2.8 MHz and at 17.5 W was the optimum condition since the contents of glucose, sucrose, total soluble carbohydrate, macro-elements (NH₄⁺-N, NO₃⁻-N, P, K, Mg, Ca and S), micro-elements (Na, Fe, Mn, Zn, B, I, Mo and Co), and pH value were similar to those in the MS medium after autoclaving. Further, when MS medium was replaced by Gamborg et al. medium (B-5) or woody plant medium (WPM) in this bioreactor at the same transducer settings, the NH₄⁺-N and NO₃⁻-N contents in nutrient mist generated were also similar to those in B5 or WPM after autoclaving, respectively. The results of this research represent a significant contribution towards development of a functional nutrient mist bioreactor.     

红星苹果矮化自根砧的营养耐旱生理特性

对嫁接在M7、M9、山定子砧木上的红星苹果的叶片解剖结构、叶绿素含量、净光合效率、矿质营养及耐旱性进行测定,结果表明,供试砧木对嫁接品种的叶片厚度、栅状组织厚度、比叶重、叶绿素含量、叶绿素a含量及净光合效率均无显著影响;叶片矿质元素含量,除M9、山定子与M7的B元素外,各砧木嫁接品种的N、P、K、Ca、Mg、Fe、Zn、Mn元素含量均无显著差异:在干旱条件下,山定子比M7、M9砧木耐旱,山定子与M7、M9对嫁接品种蒸腾强度无显著影响,但前者比后者叶片水势大,表现了耐旱的特性。     

Water deficit and polyethylene glycol 6000 affects morphological and biochemical characters of Pelargonium odoratissimum (L.)

The effects of water deficit and polyethylene glycol (PEG) 6000 on the growth and content of essential oil, photosynthetic pigments, soluble sugars, proline, macroelements (N–P–K) and microelements (Mg–Zn–Fe–Mn) of Pelargonium odoratissimum (L.) plants were investigated. Water deficits of 80% and 40% of field water capacity decreased certain growth characters (total leaf area, leaf number, and total fresh and dry mass). The photosynthetic pigments (chlorophylls a and b, total carotenoids) and mineral content (N–P–K–Mg–Zn–Fe–Mn) also decreased as water deficit level increased. Water deficit promoted the accumulation of essential oil content and its main components (methyl eugenol, isomenthone and limonene) as well as total soluble sugars and proline contents. The water deficit × PEG 6000 interaction was greater than water deficit treatments alone on all plant growth characters assessed.     

Foliar fertilization of peach (Prunus persica (L.) Batsch) with different iron formulations: Effects on re-greening,iron concentration and mineral composition in treated and untreated leaf surfaces

A trial to assess the effects of applying several Fe-containing formulations on Fe-deficient (chlorotic) peach leaves was carried out under field conditions. Solutions consisting of an Fe-containing compound (FeSO₄·7H₂O, Fe(III)–citrate, Fe(III)–EDTA, Fe(III)–DTPA or Fe(III)–IDHA) and one of five different surfactant treatments (no surfactant, an organo-silicon, an ethoxylated oil, a non-ionic alkyl polyglucoside and a household detergent) were applied to one half of the leaf via dipping, first at the beginning of the trial and then after 4 weeks. The re-greening of treated and untreated leaf areas was estimated with a SPAD apparatus, on a weekly basis, during 8 weeks. At the end of the experimental period, leaves were detached, and tissue Fe, N, P, K, Ca, Mg, Mn, Zn and Cu concentrations were determined in Fe-treated and untreated leaf areas. Treatment with Fe-containing solutions always resulted in leaf chlorophyll (Chl) increases, which however significantly depended on the Fe-source, the surfactant-type and the combination between both formulation components. Untreated leaf zones experienced a Chl increase only in some cases, and this depended on the type of surfactant used. Iron application significantly increased the Fe concentration of treated and untreated leaf areas, especially with some formulations. Foliar treatment with Fe-containing solutions induced significant changes in the concentration of several nutrients as compared to those found in Fe-deficient peach leaves, with changes being similar in treated and untreated leaf areas, although in some elements the extent of the changes was of a different magnitude in both materials. This indicates that some leaf mineral composition changes typical of chlorotic leaves are dependent on leaf Fe concentration rather than on leaf Chl levels. Results obtained are relevant to help understand the factors involved in the penetration and bioavailability of leaf-applied Fe, and to assess the potential of foliar Fe fertilization to control Fe deficiency in fruit trees.     

Effect of iron supply and nitrogen form on growth,nutritional status and ferric reducing activity of spinach in nutrient solution culture

This study was carried out in order to give some information that could improve spinach nutritional status and productivity. In this paper, the effect of two N forms (N was added either as 100% nitrate or as 80% nitrate and 20% ammonium) and three Fe levels (0 μM Fe; 20 μM FeEDDHA; 3 μM FeEDDHA + 10 mM NaHCO₃) on the growth, chlorosis symptoms and shoot nutrient element accumulation was studied in spinach plants (var. Viroflay), grown in hydroponics; six treatments and three harvests (at about 20 days interval each, until plants reached their commercial size) were applied in total. The results indicated that under conditions of Fe sufficiency (20 μM Fe), mixed N nutrition induced higher production of dry matter as well as improved Fe, Mn and Zn plant nutritional status. In plants grown under Fe deprivation (0 μM Fe), shoot Fe concentration was not significantly affected by the N form until the end of the experiment despite mixed N nutrition induced higher dry matter production up to harvest 2; plants grown under Fe deprivation and with mixed N nutrition presented also higher shoot Mn and Zn concentration. Under conditions of high concentration of bicarbonates and low level of Fe (3 μM Fe + 10 mM NaHCO₃), the N form had not a significant influence on total dry matter production whereas shoot Fe and Mn accumulation in 100% NO₃-fed plants was found to be significantly reduced compared to mixed N nutrition; regardless of the N form, those plants presented the least dry matter production, highest intensity of leaf chlorosis as well as highest root ferric reducing activity compared to plants grown under Fe deprivation.     

赣南纽荷尔脐橙叶片微量元素含量状况

为了解赣南产区纽荷尔脐橙叶片黄化原因,2008年对赣南9个县（市、区）121个脐橙园脐橙叶片微量元素进行了分析。结果表明,叶片Fe、Mn、Zn、Cu、B和Mo的含量分别为（127.90 ± 21.15）、（115.79 ± 136.72）、（16.50 ± 4.05）、（8.42 ± 9.32）、（81.88 ± 33.72）和（0.36 ± 0.14）mg · kg-1;在各脐橙园中,叶片Mo、Fe、Mn、B、Cu和Zn含量处于适量及以上水平的分别占100%、99.17%、90.91%、92.56%、62.81%和4.96%,叶片Fe、Mn、B、Cu和Zn含量处于低量水平的分别占0.83%、7.44%、7.44%、29.75%和23.97%,处于缺乏水平的仅有Mn、Cu和Zn,分别占1.65%、7.44%和71.07%。表明赣南产区脐橙叶片普遍无Mo、Fe、Mn和B缺乏问题,部分产区脐橙叶片Cu含量偏低,大多数脐橙叶片的Zn含量处于缺乏水平,生产上需要重视补充Zn肥,适量补充Cu肥。