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.     

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.     

樟树正常叶片与黄化叶片营养状况的周年变化

对位于浙江杭州钱塘江北岸滨海石灰性土壤地区黄化和正常樟树叶片营养状况年周期变化规律作了研究,结果发现黄化樟树叶片全磷比正常树高,而叶绿素计读数(SPAD值)、活性铁、全铁、全N、全K、过氧化氢酶和过氧化物酶活性比正常树低,4个取样时期樟树黄化从轻到重顺序依次为2007-08、2007-06、2007-03和2006-10,全磷与活性铁之间表现为拮抗作用,其余营养元素与活性铁之间表现为增效作用。据樟树缺铁黄化叶片营养状况年周期变化规律提出施肥建议,为预防和治理樟树黄化提供新的依据。     

Testing the ability of vivianite to prevent iron deficiency in pot-grown grapevine

Synthetic vivianite (ferrous phosphate octahydrate) has been reported to reduce the iron (Fe) deficiency symptoms in different crops growing on calcareous soils. We investigated the effectiveness of vivianite in grapevine by means of a 3-year (2002–2004) pot experiment with a Fe chlorosis-susceptible rootstock (‘110 Richter’) grown on a calcareous soil poor in available Fe. There was one treatment in which a suspension of vivianite was injected into the soil at the beginning of the experiment, one treatment with Fe chelate (FeEDDHA) applied yearly, one treatment with one initial application of both vivianite and FeEDDHA, and one control (no Fe fertilizer added) treatment. The concentration of chlorophyll per unit leaf area was estimated with a portable chlorophyll meter (readings in SPAD units). The vines fertilized with vivianite had longer shoots and higher number of leaves, and exhibited higher SPAD values than the control vines. The differences in SPAD value and pruning wood weight between the vines fertilized with Fe and the control were significant through the 3 years. There were no significant differences in SPAD value and pruning wood weight between the vines fertilized with Fe chelate and vivianite. Our results suggest in summary that vivianite is an interesting alternative to other Fe fertilizers used to prevent Fe chlorosis in grapevine judging by its effectiveness and long-term fertilizing effect. Moreover, it is not easily leached from the soil, easy to prepare, and environmentally safe.     

Evaluating foliar nitrogen compounds as indicators of nitrogen status in Prunus persica trees

Mobile nitrogen (N) forms may be better N indicators of the N status of trees than total nitrogen (TN) due to their higher sensitivity to increasing N supply. A field experiment was carried out over a 3-year period to compare foliar concentrations of total N (TN), soluble N (SN), chlorophyll (Minolta SPAD readings), NH₄–N and NO₃–N as indicators of soil N availability in nectarine, Prunus persica L. Batsch, cv. ‘Fantasia’ (grafted on ‘Nemaguard’ peach, P. persica × P. davidiana) trees. Young trees were exposed to a range of fertilizer-N application rates. Based on correlation analysis, the best association between leaf N compounds with soil N supply and trunk diameter and/or fruit yield was obtained with TN and chlorophyll SPAD readings. Leaf concentrations of mobile N compounds (NH₄–N and NO₃–N) increased more than any other N compound under high N supply; however, their inconsistency among years and low leaf concentration difficult their use as N indicators. The optimum foliar TN for growth decreased with tree age, 4.4%, 3.6% and 3.3% in non-bearing 1-year-old trees, non-bearing 2-year-old trees and 3.3 fruit-bearing 3-year-old trees. The optimum SPAD readings were 40 in 2-year-old trees and 42 in 3-year-old trees. Stable N compounds (TN and chlorophyll SPAD) could be used to N diagnosis in the zone of N deficiency, and soluble N compounds (NH₄–N and NO₃–N) to diagnoses N excess.     

Effect of 14 peach rootstocks on the yield,fruit quality,mortality, girth expansion and resistance to frost damages of May Crest peach variety and their susceptibility on Phytophthora citrophthora

The influence of 14 peach rootstocks (GF677, AN 1/6, PR204/84, KID 1, DSS, wild peach seedling, KID 2, IDS-37, Limnou, Loadel, D.1869, MRS 2/5, A/P Procopiou, Selfrooted) on the nutrient absorption, yield, fruit quality, mortality, girth expansion and resistance to frost damages of May Crest peach variety was evaluated. The results showed that the better rootstocks were considered PR204/84, GF677, AN 1/6, KID 1 and KID 2. Trees on these rootstocks produced the highest yields and relatively good fruit quality. Trees grafted on PR204/84, GF677, KID 1 and KID 2 rootstocks were resistant to frost damage. In contrast, scion on the rootstock AN 1/6 were susceptible to frost damage. The mortality of trees grafted on AN 1/6, KID 1 and KID 2 was 0%. Trees grafted on PR204/84 and GF677 showed 40% mortality. The rootstocks GF677, AN 1/6, KID 1 and KID 2 had similar girth expansion. In contrast, the girth expansion of PR204/84 was significantly lower. Generally, rootstocks with the lowest level of P had the highest level of K and Ca. The converse was also true.All rootstocks showed similar susceptibility to Phytophthora citrophthora.     

Impact of iron stress on biomass,yield, metabolism and quality of potato (Solanum tuberosum L.)

In order to study the influence of variable iron on biomass, economic yield and role of iron in potato (Solanum tuberosum) cv. Chandramukhi metabolism, plants were grown in refined sand at variable iron ranging from 0.001 to 2.0 mM. Exposure of potato plants to Fe stress (i.e. a Fe concentration different from 0.1 mM) shows retarded growth, decreased chlorophyll concentration and Hill reaction activity, induced changes in enzyme activities and concentration of Fe and Mn. The visible symptoms of iron deficiency appeared on day 15 at 0.001 mM Fe as chlorosis of young leaves. The excess of iron (at >0.1 mM Fe) appeared later, after 25 days and the chlorosis was observed on older leaves. Both deficiency (0.001 mM) and excess (>0.1 mM) of iron reduced the tuber yield, deteriorating its quality by lowering the concentration of sugars, starch and protein nitrogen and increasing the accumulation of non-protein nitrogen and phenols in tubers.     

不同砧木对先锋橙矿质营养元素含量的影响

在田间试验条件下,观察了12种砧木的先锋橙矿质营养元素含量。在观察的11种营养元素中,不同砧木间除 N、Zn、Mo元素含量无显著差异外,其它元素均达显著或极显著差异。其中微量元素的变幅大于大量元素。植株营养状况以宜昌橙类(除 K)、枳类(除 Fe)和桔类砧木植株的养分含量较高,果实含酸量高的砧木植株养分含量偏低。耐碱砧木主要表现在Fe、Mn及 K、Cu元素含量的差异。     

铁肥虹吸输液方法对矫正苹果缺铁失绿症的影响

【目的】为了探索苹果叶片缺铁失绿矫正新方法,【方法】通过田间试验和盆栽试验,分别研究了铁肥虹吸输液对矫正苹果缺铁失绿症的影响,铁肥虹吸输液和强力高压注射对叶片和根中铁含量的影响及铁在树体内的运输与分布。【结果】结果表明,铁肥虹吸输液能够在较短时间内使黄化的叶片复绿,显著增加叶片中叶绿素含量。虹吸输液增加叶片中铁含量显著多于强力高压注射,强力高压注射增加根中铁含量显著高于虹吸输液,虹吸输液铁肥靠叶片蒸腾拉力进入树体,强力高压注射的铁肥靠压力进入树体。【结论】铁肥虹吸输液是矫正苹果缺铁失绿症一种新的高效、简单易行方法。     

果树叶片中不同形态铁含量与失绿黄化病关系研究

对果树叶片中全量铁、HCl提取铁和Fe~(2+)含量分析结果表明:果树黄叶中含有与正常绿叶一样多甚至高于绿叶的全量铁,但用HCl提取的铁和Fe~(2+)的数量则明显比绿叶少。在绿叶中全量铁和HCl提取铁的比率保持着一定的稳定平衡,在桃叶中全量铁/酸提取铁比率大约是2.1。失绿黄叶由于活性铁减少而使比率增大,从而使植株中铁营养代谢失调。因此,全量铁/酸提取铁比率能较好地反映植株铁营养状况。在失绿黄叶中K和P比绿叶高,而Ca含量低,K和Fe成显著负相关。当桃树施用钾肥时,叶子中K~+浓度增加而Fe减少,使K/Ca和K/Fe比显著增大。     

Effects of multiple applications of methyl jasmonate on fruit ripening,leaf gas exchange and vegetative growth in fruit trees

Summary

Multiple applications of methyl jasmonate (Me-J), at 10.mM, enhanced the rate of fruit ripening in peach ‘Redhaven’. The effect of Me-J on red colour development and fruit firmness was most pronounced in fruit treated six times with Me-J. Lower concentrations of Me-J had no effect of fruit colour. Me-J, at 10.mM, significantly reduced stomatal conductance, photosynthetic rate and transpiration rate of crabapple leaves, but had no effect on these parameters in peach leaves. The short-term inhibitory effects of Me-J on leaf gas exchange in crabapple persisted for up to 24 h. Fourteen applications of Me-J over a period of 28 days resulted in a 60% decrease in the concentration of chlorophyll in leaves. These Me-J applications also reduced the length of new branches, leaf number and leaf fresh weight by 65%, 31% and 47%, respectively. In peach, Me-J induced some leaf chlorosis and early leaf senescence within two weeks of the treatments which resulted in significant reductions in shoot length.     

苹果不同施肥方式对铁的吸收、运输与分配的影响

 红色邻二氮杂菲铁示踪结果表明: 二价铁肥根系输液以二价态由根被动吸收, 由靠近形成层的木质部, 运输到根、茎、叶及其主脉内, 运输速度每小时可达数十厘米。室内营养液培养的八棱海棠苗用⁵⁹Fe示踪, 结果表明, 断根中分配的⁵⁹Fe为19.3% , 叶中70.9% , 断1、2、3条根⁵⁹Fe在叶中分配的比例分别为57.9%、63.6%和68.0%。铁肥树干强力高压注射以二价铁沿中央木质部的导管运输, 大部分向下运往根系, 根中贮存大量的铁, 向上运输稍难。运输速度每小时达数百厘米, 矫正缺铁失绿症的速度比根系输液慢, 但由于根中贮存大量的铁, 持效期较长。铁可以通过枝条和叶片进入树体并且运输。     

果树的缺铁失绿症—文献述评

本文综述了国内外对果树缺铁失绿症的主要研究结果,特别是近期的进展,包括诱致失绿的内外因子,果树吸收、运转铁的机理及利用铁的特点,铁的螯合作用和螯合铁的应用,防治缺铁失绿的途径。     

Comparison of three pea cultivars (Pisum sativum) regarding their responses to direct and bicarbonate-induced iron deficiency

The aim of this work was to explore leaf characteristics underlining the difference in the sensitivity of pea cultivars (cv. Kelvedon, Douce and Lincoln) to Fe deficiency. Plants were grown in a greenhouse under controlled conditions in continuously aerated solution. Three treatments were used: 30 μM Fe (+Fe), 0 μM Fe (−Fe); direct deficiency and 30 μM Fe + 10 mM NaHCO₃ (+Fe+Bic); indirect deficiency for 12 days. Growth parameters, iron status, potassium content, chlorophyll fluorescence and photosynthetic capacity were studied. Our results showed that Fe deficiency led to a significant decrease of chlorophyll index (SPAD readings) and bivalent iron content in all Pisum sativum cultivars. The lower reduction was observed in Fe-deficient plants of Kelvedon and Douce. In addition, shoot length and whole plant dry weight were not affected by Fe deficiency in the latter cultivars. Both tolerant cultivars showed higher accumulation of potassium content in their leaves compared with the sensitive one. Moreover, both chlorophyll fluorescence ratios (F_v/F_m and F_v/F₀) were significantly decreased in all cultivars under both Fe deficiency treatments. The photosynthetic electron transport activity was reduced in the sensitive cultivar, especially in the absence of iron. The adverse effect of bicarbonate-induced Fe deficiency on the above mentioned parameters were more pronounced than that of the direct one. The capacity of both tolerant cultivars to preserve adequate chlorophyll synthesis, photosynthetic capacity and plant growth under iron-limiting conditions is related to the suitable nutrition of their leaves in ferrous iron, due to (at least partially) their higher potassium content.     

Phosphorus toxicity in the Proteaceae: A problem in post-agricultural lands

South African Proteaceae are adapted to the low soil phosphorus (P) concentrations of the Cape Floristic Region. The efficient P uptake by Proteaceae means that these plants experience phosphorus (P) toxicity at lower rhizosphere [P] than crop plants. This is only problematic when cultivating Proteaceae (and many plants from this region) on previously agricultural land with high residual soil [P]. In this study we hypothesize that P toxicity will result in element imbalances in leaves of Proteaceae and information from this study aims to facilitate ameliorative treatments. Phosphorus toxicity was induced on-farm in Leucadendron ‘Safari Sunset’ (Proteaceae) with subsequent mapping of element distribution in non-necrotic leaf tissue using micro particle-induced X-ray emission spectrometry. Phosphate supply up to 0.01 mM in a fertigation solution resulted in increased stem length of Leucadendron ‘Safari Sunset’ while P concentrations in excess of this resulted in decreased stem length, increased leaf [P] up to 0.25% (w/w) and, between 1 mM and 5 mM P supply, typical P toxicity symptoms were observed. High P supply (5 mM P) resulted in increased leaf [P] in most leaf tissues including the epidermis, where calculations from an equilibrium speciation model indicated that there was 30% more dissolved PO₄³⁻ in the epidermis compared to leaves at low P supply (0 mM added P on soil with 34 mg P kg⁻¹). Concomitantly, bundle sheath and epidermal [Ca] were reduced and 10% more Ca was predicted to be adsorbed and precipitated as hydrapatite at high P supply. High P supply resulted in increased leaf [Cl] and [Mn] in all tissues studied; decreased total leaf [Fe], bundle sheath, xylem, phloem and epidermal [Fe] and decreased total leaf [Zn] and xylem and phloem [Zn]. The observed symptoms of P toxicity in Leucadendron ‘Safari Sunset’ (necrosis in some plants, chlorosis and leaf rosetting) co-occurred with (1) excess PO₄³⁻, which may bind Ca in the epidermis (leading eventually to necrosis); (2) reduced [Fe] and increased [Mn] (leading to chlorosis) and (3) reduced total and vascular [Zn] (leading to leaf rosetting).     

Influence of different vigour cherry rootstocks on leaves and shoots mineral composition

In this study, the field performance of Adara, CAB 6P, Gisela 5, MaxMa 14, Saint Lucie GF 64 (SL 64), Saint Lucie GF 405 (SL 405), and Tabel-Edabriz rootstocks, grafted with two sweet cherry cultivars (‘Stark Hardy Giant’ and ‘Van’, Prunus avium L.), were compared after 7 years of planting on a calcareous clay-loam soil. The leaf and shoot mineral elements analysed were N, P, K, Ca, Mg, Fe, Mn, Zn, Na and Cu. In the case of both cultivars, tree vigour and cumulative yield were highest on Adara, whereas yield efficiency was greater on Gisela 5. All rootstocks induced low leaf Fe concentrations, although visual chlorosis symptoms were not observed. In both cultivars, significant positive correlations between Mn shoot and leaf concentration were found. Significant positive correlations were also found between yield efficiency and shoot mineral concentration, with the exception of Mg and Zn, which showed no correlation, and K with negative correlation. In ‘Van’ cultivar, Adara rootstock followed by CAP 6P and Gisela 5 showed the most balanced nutritional values. On the other hand, SL 64 had leaf mineral element concentrations below the optimum, probably due to the bad adaptation to heavy soil conditions.     

The Effect of Some Latent Virus Infections on the Growth and Cropping of Apples

SUMMARY

Seedlings of Newton Wonder apple multiplied vegetatively on Malus sikkimensis rootstocks and inoculated with a mixture of chlorotic leaf spot, scaly bark and dwarf viruses showed varying degrees of sensitivity to these infections. Although none of the seedlings showed clearly recognizable virus symptoms, many showed a very significant reduction in vigour; the girth differences between the infected and control trees were still increasing three years after inoculation.

The infected trees showed signs of nitrogen deficiency, which were confirmed by foliar analysis ; leaf nitrogen as percentage of dry weight was 10% lower than that of the controls. Four years after inoculation 43% of the infected trees had cropped, compared with 58% of the controls.

The results suggest that some selection of varieties and rootstocks for virus tolerance has taken place and that the evaluation of new seedlings on their own roots may not be a true indication of their performance on infected rootstocks.     

不同品种蓝莓植株失绿的叶片和土壤诊断及分析

以4种蓝莓失绿植株的根际土和黄化叶片为试材,分析了各根际土壤的K、P、Ca、Mg、Zn、Cu、有效铁含量和植株叶面积、叶绿素a、叶绿素b、有效铁含量等指标,以探究蓝莓植株黄化的原因。结果表明:4种蓝莓的各级黄化叶的叶面积(重度黄化叶下降15.5%～37.5%)、叶绿素b(重度黄化叶下降43.8%～71.0%)和有效铁含量低于健康叶(重度黄化叶下降14.7～19.7%),重度黄化叶的叶绿素a含量低于健康叶(下降72.5%～76.8%);4种蓝莓黄化植株的根际土壤有效铁含量低于健康植株(重度黄化植株的下降16.7%～22.1%),依次为健康植株>轻度黄化>中度黄化>重度黄化;重度黄化植株根际土壤的K、P含量高于或等于健康植株;除"蓝金"品种外,其它品种重度黄化植株根际土壤的Ca含量低于或等于健康植株;除"伯克利"品种外,其它品种根际土壤的Mg含量与健康植株相等;除"莱克西"品种外,其它品种根际土壤的Zn含量低于健康植株;4种蓝莓重度黄化植株根际土壤的Cu含量与健康植株相等。因此,蓝莓植株叶片黄化的原因是由于土壤中的有效铁含量较低,K、P含量过高,从而造成叶片有效铁含量过低,叶绿素含量下降,最终导致叶片黄化。     

Influence of rootstock on orchard productivity and fruit quality in peach cv. ‘Redhaven’

Summary

We have evaluated the influence of four different peach rootstocks (Prunus pumila,‘GF 655/2’ ,‘Missour’ and ‘GF 677’ as a standard) planted in medium-heavy to heavy soil on phenological events (flowering and harvest date), growth, yield, fruit quality and mortality of peach (P. persica L.) scions of cv. ‘Redhaven’. At the end of flowering, there were no significant differences between the different rootstocks in the years 1999, 2000, 2003 and 2004. In 2001, trees grafted on P. pumila reached the end of flowering 2 d before trees grafted on the other rootstocks. ‘Redhaven’ fruits ripened on the same day on trees grafted on the different rootstocks. The differences were only between years. The results showed that significantly less vigorous trees, according to their trunk cross-sectional area (TCSA) and canopy volume, with the lowest yield, were observed on P. pumila rootstock. The rootstock P. pumila had a significant negative influence on fruit dimensions and mortality was 50%. Trees grafted on ‘GF 655/2’ rootstock produced significantly lower yields than those grafted on ‘GF 677’ or ‘Missour’ rootstocks. Only the ‘GF 655/2’ rootstock had root suckers. Trees grafted on ‘GF 677’ rootstock were significantly more vigorous than on the other rootstocks, and produced the highest yield with good fruit quality. The final canopy volumes of peach trees grafted on the different rootstocks were very different. The most vigorous trees were those grafted on ‘GF 677’ rootstock, where the final tree volume was 12.8 m³. Trees grafted on P. pumila and ‘GF 655/2’ had significantly lower TCSA values than on the other rootstocks.     

柑橘4种砧木幼苗对铜过量胁迫的生理响应与耐受性差异

为探究不同柑橘砧木的铜过量胁迫耐性差异,分析砧木铜过量胁迫的生理响应,试验选用4种常用的柑橘砧木枳、资阳香橙、红橘和沙田柚180 d实生苗为材料,用1.5（对照）、7.5、37.5、187.5和937.5 μmol • L-1的CuSO4溶液进行处理。结果显示,高浓度CuSO4处理导致叶绿素含量和光合能力下降,叶片细胞相对电导率和MDA含量值显著上升;SOD、POD酶活性上升;高浓度下,砧木对K、P、Ca、Mg、Fe、Mn和Zn营养元素的吸收和转运下降。高CuSO4处理导致砧木叶片黄化脱落,根系褐变短小,生长受阻,严重时死亡。不同砧木对CuSO4过量胁迫耐受性差异明显,枳最先出现新叶失绿、老叶落叶、生长量下降和光合等生理指标下降,随后依次为沙田柚、红橘和资阳香橙。主成分分析和隶属函数综合分析显示,资阳香橙对铜过量胁迫耐性最强,红橘其次,沙田柚再次,枳对铜过量胁迫最敏感。