Published in Agron J 100:813-818 (2008)
DOI: 10.2134/agronj2007.0257
© 2008 American Society of Agronomy
677 S. Segoe Rd., Madison, WI 53711 USA
FERTILIZER MANAGEMENT
IDHA Chelates as a Micronutrient Source for Green Bean and Tomato in Fertigation and Hydroponics
Juan José Lucenaa,*,
José Antonio Sentísa,
María Villéna,
Teresa Laob and
Mónica Pérez-Sáezb
a Dep. of Agricultural Chemistry, Univ. Autónoma, 28049 Madrid, Spain
b Dep. of Vegetal Production, Univ. de Almería, 04120 Almería, Spain
* Corresponding author (juanjose.lucena{at}uam.es).
 |
ABSTRACT
|
|---|
The new biodegradable chelating agent imidodisuccinic acid (IDHA) has been studied for its application in agriculture. This study was conducted to compare the efficiency of mixed IDHA and ethylene diamine tetraacetic acid (EDTA) formulations to provide Fe, Mn, Zn, and Cu to green bean (Phaseolus vulgaris ‘Perfección negra polo’) and tomato (Lycopersicum esculentum Mill. ‘Shiren’) plants grown in greenhouses in soil-less and soil cultures in fertigation conditions. The effect on micronutrient concentrations, SPAD index and fruit yield were investigated. In the green bean experiment, control (no chelate applied) plants showed important micronutrient deficiency symptoms and growth reduction, while IDHA treated plants were healthy. Although EDTA provides micronutrients in higher amounts than IDHA, a chryptogamic infection was observed for this treatment but not for the IDHA one. In the tomato grown on rockwool experiment, increments of SPAD index and Zn concentration are higher in plants treated with IDHA than with EDTA, though for the tomato on soil mulch experiment no differences were found among treatments, even the control. The results are in agreement with previously published studies on the behavior of IDHA. The new chelating agent IDHA can substitute EDTA in hydroponics and fertigation cultures as a chelating agent for micronutrients.
Abbreviations: AAS, Atomic Absorption Spectrometry • EDTA, ethylene diamine tetraacetic acid • IDHA, N-(1,2-dicarboxyethyl)-D,L-aspartic acid • o,o-EDDHA, ethylendiamine-N,N'-bis(o-hydroxyphenylacetic) acid • o,p-EDDHA, Ethylenediamine-N-(o-hydroxyphenylacetic)-N'-(p-hydroxyphenylacetic) acid
|
NOTES
|
|---|
All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher.
Received for publication July 25, 2007.
|
INTRODUCTION
|
|---|
IRON CHLOROSIS is a nutritional disorder in plants that affects their development and decreases the yield of many crops growing on calcareous soils where CaCO3 buffers soil solution pH in the range of 7.5 to 8.5 (Lindsay and Schwab, 1982) and high bicarbonate concentrations are present (Lucena, 2000). Chlorosis implies a decrease in the amount of chlorophyll and, therefore, a gradual disappearance of the green color of the plants (Chen and Barak, 1982; Mengel et al., 2001).
In the case of Zn, high pH and the presence of active lime in soil induces the retention of the cation, due to the adsorption and the precipitation of Zn solid phases (Lindsay, 1972; Papadopoulos and Rowell, 1989; Uygur and Rimmer, 2000). The solubility of Mn is affected by pH, redox, and complexation and its availability is lower in alkaline soils due to low solubility of Mn compounds under high pH conditions (Lindsay, 1979).
The use of chelates is the most common and efficient agricultural practice to treat Fe chlorosis and other micronutrient deficiencies (Álvarez-Fernández et al., 2005). Recently, the biodegradable chelating agent N-(1,2-dicarboxyethyl)-D,L-aspartic acid (Fig. 1
), commonly known as imidodisuccinic acid or IDHA, has been proposed for its use in agriculture (Mitschker et al., 2004). The IDHA shares structural similarities with EDTA but only contains five functional groups able to complex the metal. Recently, García-Marco et al. (2006) suggested that o,p-EDDHA/Fe3+, also with five functional groups complexing Fe, was the fastest substrate tested for the Fe chelate reductase in cucumber (Cucumis sativus ‘Ashley’) (Fe efficient) plants and it was also faster than o,o-EDDHA/Fe3+ at regreening Fe chlorotic soybean (Glycine max ‘Oshumi’) (Fe susceptible) plants. Moreover, the chelating agent was quick to solubilize native Fe from insoluble materials. This behavior may be related to the presence of only five bonds between the Fe and the ligand (Gómez-Gallego et al., 2002) while chelates with six bonds (e. g. o,o-EDDHA or EDTA) present slower rates of action. Villén et al. (2007) demonstrated that despite IDHA/Fe3+ having lower stability than EDTA and high reactivity in agronomic conditions, it is quite efficient in providing Fe to cucumber and soybean plants grown in hydroponics at pH 7.5 in a growth chamber. This good behavior in plant experiments may be related to the presence of only five bonds between the Fe and the chelating agent as in o,p-EDDHA.
The IDHA is biodegradable (Novack and Vanbriesen, 2005), so its use as Fe fertilizer could be a more environmentally friendly choice than other synthetic chelates. However, there is little information about the effectiveness of the IDHA as chelating agent in fertilizers. Gorelov et al. (1987) demonstrated that IDHA chelates were effective to treat chlorosis in grape (Vitis vinifera L). Moreover, IDHA/Zn2+ increased grape sugar level and a mix of IDHA/Zn2+ and IDHA/Fe3+ increased yields of rice (Oryza sativa L.) and alfalfa (Medicago sativa L.) seeds. Fernández et al. (2006) demonstrated that rates of foliar penetration of Fe from IDHA/Fe3+ produced a higher leaf chlorophyll content than DTPA/Fe3+, but lower than EDTA/Fe3+ when it was applied with surfactants and other adjuvants. Schlegel et al. (2006) tested the foliar penetration of different Fe compounds in leaf dicks of broad bean at 100% humidity. Penetration followed first order-kinetics and the rate constants (h–1) were higher in light than in dark conditions and were larger for CaCl2, than lignosulfonate, IDHA and the least effective was citrate. Regardless of the early report of Gorelov et al. (1987) and the foliar uptake studies, IDHA has not been tested as a complexing agent of Fe, Mn, Cu, or Zn in agronomic conditions. Application to highly calcareous soils may not be successful due to the low stability, but the behavior in fertigation conditions should be evaluated. The objective of this paper is to compare the efficacy of IDHA and EDTA formulations to provide micronutrients in tomato and green bean crops grown in soil-less and soil cultures under fertigation.
|
MATERIALS AND METHODS
|
|---|
Three experiments were conducted during 2006. Green bean on rockwool was grown in the experimental greenhouse of the Universidad Autónoma (40° 33' N, 3° 42' W, 724 m elevation, Madrid). Two tomato experiments were developed in commercial greenhouses in the Motril region. One of them was conducted in Lobres (36° 46' N, 3° 35' W, 152 m elevation, Granada) using tomato as test plants and rockwool as the growth media. Rockwool is chemically inert (Cation Exchange Capacity nil at pH 7.3) and physical properties are presented in Table 1
. The other experiment was conducted in Carchuna (36° 42' N, 3° 27', sea level, Almería) using tomato plants on a soil mulch (enarenado) system. Enarenado is commonly used in the greenhouses of Almería (southeastern Spain) and is an artificial substrate. In this case, enarenado consisted of a bottom layer of native poor soil (Table 2
), then a 2 cm layer of sheep (Ovis aries) manure and on the top a 10 cm layer of sand. Enarenado has many advantages: little management, reduced water loss and salinity problems, and higher temperature during winter (La Malfa and Leonardi, 2001).
View this table:
[in this window]
[in a new window]
|
Table 2. Average chemical and physical characteristics of the soil in the greenhouse where the soil mulch experiment was carried out.
|
|
For the green bean experiment, seeds were washed with water and commercial NaClO diluted 10% during 30 min, rinsed with water and finally with distilled water. Three seeds were placed directly into ‘rockwool cubes’ (10 cm L x 10 cm W x 10 cm H) previously saturated with water during 3 d in darkness (28°C). Next, the cubes were placed in a growth chamber for 3 d with a light/dark regime of 16/8 h, 30/20°C temperature and 50% humidity. During this time, plants were watered with a diluted fertilizer solution of macronutrients. When plants were around 20 cm tall, the cubes were placed into the greenhouse on 120 cm L x 20 cm W x 10 cm H rockwool bags previously saturated with the macronutrient solution. When roots were spread on the rockwool bag the plants were thinned to two plants per cube. Five lines with three rockwool bags (one of each treatment) were used and each line corresponded to a different experimental block.
Nutrient solution was continuously added as the irrigation solution. The macronutrient solution consisted of (mM): 3.3 Ca(NO3)2, 2.4 KNO3, 1.0 MgSO4, and 1.0 KH2PO4, prepared with irrigation water that contained 0.1 g dm–3 solid CaCO3 and 0.1 g dm–3 NaHCO3 (pH around 8.2). The nutrient solution in the rockwool bags presented an average pH of 6.4 and electrical conductivity of 1.4 dS m–1. Three different treatments were applied in the irrigation: Control (without micronutrient solution), IDHA and EDTA. Micronutrient solutions contained (µM): 18 Fe, 9.1 Mn, 1.5 Zn, 0.63 Cu, 9.3 B, and 0.42 Mo. Micronutrient solutions were prepared using different IDHA solid products [8.5% Fe as IDHA/Fe3+, 7.5% Mn as IDHA/Mn2+, 9.0% Zn as IDHA/Zn2+ and 9.0% Cu as IDHA/Cu2+ (w/w)] or an EDTA commercial mix product containing 7.5% Fe as EDTA/Fe3+, 3.5% Mn as EDTA/Mn2+, 0.7% Zn as EDTA/Zn2+, 0.28% Cu as EDTA/Cu2+, B 0.65% and Mo 0.3% (w/w). Molybdenum and B were applied in the IDHA treatment as H3BO3 and (NH4)6Mo7O24·4H2O. Irrigation was applied for 5 min every 2 h with a drip rate of 2 L h–1.
Tomato seedlings used in the greenhouse experiments in Granada and Almería were from commercial sources. In the tomato on rockwool experiment, seven blocks (two of them as borders) were used. Two paired bags (120 cm L x 20 cm W x 10 cm H) from each treatment (one for IDHA and other for EDTA) were used to form a block and five plants per bag were used. Two drippers were placed in each bag, one of them feeding two plants and the other one feeding three plants. Nutrient solutions were continuously added as irrigation solutions. The macronutrient solution consists of (mM): 3.5 Ca(NO3)2, 5.0 KNO3, 1.0 MgSO4, 1.5 H3PO4 dissolved in brackish water (pH around 8.2) The micronutrient solution had the following composition (µM): 27 Fe, 11 Mn, 1.8 Zn, 0.94 Cu, 13 B, and 0.42 Mo. The two different treatments were: EDTA (commercial product as in the green bean experiment) and IDHA as different solids and liquid products (4.3% (w/v) Fe as IDHA/Fe3+, 7.5% (w/w) Mn as IDHA/Mn2+, 5.4% (w/v) Zn as IDHA/Zn2+ and 6.1% (w/v) Cu as IDHA/Cu2+. The pHs of the solutions were adjusted to 5.8 with nitric acid.
In the tomato soil mulch experiment, three irrigation lines of the greenhouse were used. Macronutrient solutions were prepared as in the previous experiment, but the interaction with the limestone sand rises the pH of the substrate considerably. Three treatments were distributed in four different blocks. In each block, five plants in the row were used for each treatment. The chelate solutions were injected (two injections of 25 mL were applied to both sides of the plant, 10 cm apart from the stem) every 2 wk directly to the soil; their composition was (mM): 1.53 Fe, 0.73 Mn, 0.12 Zn, 0.05 Cu, 0.68 B, and 0.04 Mo. Three different treatments were applied: the control (without micronutrient solution), IDHA and EDTA. The micronutrient solution (the total amount of micronutrients applied during this experiment was calculated to be the half of the total amount applied in the rockwool experiment) was injected as IDHA and EDTA (products described in the previous tomato experiment).
In all experiments, Soil-Plant Analysis Development (SPAD) index readings (average of 15 leaves and three readings per leaf) were taken every week with a chlorophyll-meter (Minolta SPAD-502). The youngest developed leaves were sampled at 29, 39, and 49 d in green bean, 21 and 70 d in tomato rockwool and 13, 62, and 146 d in tomato soil mulch experiments after the treatment application. Sampled leaves were separated and washed with Tween 80 in 0.1 M HCl for 10 s (Álvarez-Fernández et al., 2001), and then with abundant distilled water, weighed and dried. After dry mineralization, micronutrient concentrations were determined in leaves by AAS (PerkinElmer AAnalyst 800). In the green bean experiment, growth rate (height) was collected during the first days after the treatment application. After the first sampling time, both plants of the middle cube of each bag were taken and biometric data was recorded. Pod yield was determined at all sampling times. In the tomato soil mulch experiment, stem diameter and fruit yield were also collected. In the tomato rockwool experiment, plants developed an incidental acidic stress from Day 80 that could affect fruit yield and other biometric data so they were not recorded.
Data were statistically evaluated by using the analysis of variance (
= 0.05) and the Duncan's Multiple Range ( = 0.05) test with the program SPSS 13.0 to find significant differences among treatments.
|
RESULTS
|
|---|
Green Bean in Hydroponics
As expected, the control treatment showed significantly lower SPAD index values than the other treatments (Table 3
) and agreed with the visual symptoms of micronutrient deficiency that the control plants exhibited from the first days of the experiment (Fig. 2
). The IDHA and EDTA treatment have similar SPAD index readings until Day 31 and then the IDHA treatment shows significantly higher values than the EDTA treated plants because plants treated with EDTA began to show visual symptoms of fungus infection related to warm weather and dryness (Fig. 3
and 4
). In the last sampling time, EDTA plants were severely injured while the IDHA plants showed only a few symptoms.
View this table:
[in this window]
[in a new window]
|
Table 3. Effect of the micronutrient chelate treatments on the SPAD index for the green bean experiment conducted in the experimental greenhouse of the Universidad Autónoma during 2006.
|
|
View larger version (76K):
[in this window]
[in a new window]
|
Fig. 2. Visual aspect of green bean plants development in the experimental greenhouse of the Universidad Autónoma during 2006, after 15 d of treatment.
|
|
View larger version (62K):
[in this window]
[in a new window]
|
Fig. 3. Visual aspect of the green bean plants 39 d after the beginning of the treatments. Ethylene diamine tetraacetic acid (EDTA) treated plants suffer from fungus infection while control plants presented typical multi micronutrient deficiencies.
|
|
Micronutrient concentrations in the leaf are presented in Table 4
. The low concentrations in the control treatment are in good agreement with the visual symptoms of deficiency and the SPAD index. Both EDTA and IDHA treatments present significantly higher values than the control and are in the sufficiency range (Jones et al., 1991), except for Mn in the IDHA treatment. Iron concentration is higher for EDTA than for IDHA in all the sampling times and Mn and Zn concentrations are different after the first sampling time.
View this table:
[in this window]
[in a new window]
|
Table 4. Effect of the different micronutrient chelate treatments on leaf Fe, Mn, Zn, and Cu concentrations and micronutrient ratios in green bean plants, grown in hydroponics in the experimental greenhouse of the Universidad Autónoma during 2006, 29, 39, and 49 d after the beginning of the treatments.
|
|
Several nutrient ratios have been considered (Table 4) as Fe nutrition indexes. Despite the differences in nutrient content between EDTA and IDHA, the Fe/Mn and Fe/micros ratios do not have significant differences between them, indicating a similar Fe, Mn, and Zn nutrient balance. The Fe to Cu ratio is higher for the EDTA for all the sampling times. The IDHA is able to provide micronutrients to the plant in an effective way, but in fewer amounts than EDTA, but nutrient ratios indicate a good equilibrium among micronutrients for both treatments.
In Fig. 5
, plant height at the early stages of the experiment is presented. No differences were found between IDHA and EDTA treatments indicating that the plants presented similar development although there were clear differences with respect to the control.
In Fig. 6
, the fresh weight of the green bean plants sampled 29 and 49 d after application is presented. The IDHA has significantly higher values than the EDTA experiment and the control has very low values. A decrease in fresh weight between the two sampling times, due to leaf dryness in the control and EDTA treatments, is observed. It was clear that leaf dryness in EDTA treatment was due to the fungus attack and it was not a direct effect of the treatment. However, control plants were very affected by micronutrient deficiencies as well as with fungus attack at some extension, both causing leaf dryness. Similar results are found for the number of pods collected in each sampling time (Fig. 7
), the yield of the plants (Fig. 8
) and the average pod weight, caliber, and length (data not shown).
View larger version (17K):
[in this window]
[in a new window]
|
Fig. 6. Fresh weight of the green bean plants grown in hydroponics and sampled 29 and 49 d after the beginning of the experiment.
|
|
View larger version (16K):
[in this window]
[in a new window]
|
Fig. 8. Weight of green bean pods (g/plant) sampled 29, 39, and 49 d after the beginning of the treatments.
|
|
Tomato on Rockwool
With respect to the SPAD index (Table 5
), the EDTA treatment maintains the initial level during the 80 d of the experiment while IDHA shows a SPAD index increment of 6.4 units higher than the EDTA at the end of the experiment.
View this table:
[in this window]
[in a new window]
|
Table 5. Effect of the micronutrient chelate treatments on the SPAD index in the rockwool tomato experiment development in a commercial greenhouse of Lobres (Granada, Spain), during 2006. Data are presented as change in SPAD readings ( SPAD) with respect to treatment application date.
|
|
Micronutrient concentrations and ratios in leaves are presented in Table 6
. Concentrations are in the sufficient range (Jones et al., 1991), except for Zn in the second sampling time in EDTA and IDHA treatments. At both sampling times, there were not significant differences between treatments except for Cu. For the IDHA treatment, Fe to Mn, Fe to Cu, and Fe to micros ratios, are significantly lower than for EDTA in the second sampling time. This indicated that IDHA treatment has a higher selectivity for Mn and Cu with respect to Fe than EDTA.
View this table:
[in this window]
[in a new window]
|
Table 6. Effect of the different micronutrient chelate treatments on leaf Fe, Mn, Zn, and Cu concentration and nutrient ratios in tomato plants, grown in rockwool hydroponics in a commercial greenhouse of Lobres (Granada, Spain) during 2006, 21, and 70 d after the beginning of the treatments.
|
|
Tomato on Soil Mulch (Enarenado)
The SPAD indexes for the tomato on soil mulch experiment (data not shown) reveal that IDHA produced significantly (Duncan test P > 95%) higher values than EDTA. Differences are only 1.06 units in the average of 25 sampling times and surely of little agronomic relevance. However, no differences were found with respect to the control, which raises doubts about the efficacy of the low frequency addition of these chelates to tomato grown in enarenado.
In the first sampling time, Fe concentration (Table 7
) in the IDHA treatment is significantly lower than in the other ones but, for the second and third sampling time, there were no significant differences among treatments. For the rest of the elements, there were no differences except for Zn in the third sampling time, being higher for EDTA and IDHA treatments than for the control. In fact, Zn levels were deficient in the control (Jones et al., 1991), indicating that, despite observing no differences on the SPAD index, the preventive use of the chelates has been effective to overcome nutrient alteration. Micronutrient ratios (Table 7) yield similar observations as with nutrient concentrations with respect to Fe nutrition. High amounts of Cu in first and second sampling times (data not shown) were due to the fungicide application in the greenhouse.
View this table:
[in this window]
[in a new window]
|
Table 7. Effect of the different chelate treatments on leaf Fe, Mn, Zn, and Cu concentration and nutrient ratios in tomato plants, grown on soil mulch in a greenhouse of Carchuna (Almería, Spain) during 2006, 13, 62, and 146 d after the beginning of the treatments.
|
|
Fruit yield and stem diameter were recorded at different times along the experiment and there were no statistical differences among treatments (data not shown).
|
DISCUSSION
|
|---|
In a previous paper, the authors demonstrated that, despite the fast action of IDHA, its Fe chelate presents lower stability than EDTA/Fe3+ and high reactivity in agronomic conditions (Villén et al., 2007). These results are in agreement with the results obtained for the tomato on soil mulch experiment where the low frequency of application and the high interaction with the substrate reduces the effectiveness of the Fe application. Consequently, no differences among treatments were observed with respect to Fe. Moreover the results of Fe concentration in leaves did not correlate with the SPAD indexes. At the beginning of the experiment, IDHA presents higher SPAD index values but lower Fe concentration than the other treatments. Tomato plants are not highly sensitive to Fe chlorosis and Fe application is more a preventive treatment than a curative one. Also, IDHA/Fe3+ and EDTA/Fe3+ show a great retention in soils and soil materials and should not be present in the soil solution in calcareous soils (pH around 8.5) where Fe chlorosis is more severe, but they can remain in nutrient solutions of pH 7.5 or lower, such as those used in fertigation or hydroponics (Villén et al., 2007).
There was an improvement in Zn nutrition with the EDTA and IDHA treatments. Lindsay (1972 and 1979) reported a higher stability of EDTA/Zn2+ than EDTA/Fe3+ in soils at pH more than 6.2 and it is the predominant EDTA species till pH 7.2. Also calculations using the data of Hyvönen et al. (2003) indicates that the IDHA/Zn2+ chelate is more stable along all the pH range of soils than IDHA/Fe3+ and more stable than IDHA/Ca2+ bellow pH 7.0. Then, in the experimental conditions and despite the low frequency of chelate applications, Zn is maintained soluble and available for the plants by both chelates.
In hydroponics on rockwool there is a high frequency of application (continuously as in the irrigation solution) so there is less interaction between the solution and substrate and the efficiency of the IDHA treatment to provide micronutrients to green bean and tomato plants has been clearly demonstrated. In the green bean experiment, IDHA produced healthy plants, with equilibrated foliar content of micronutrients, adequate SPAD indexes, increased pod yield and quality parameters. The EDTA can provide micronutrients in larger amounts than IDHA, which is in good agreement with the theoretical calculations using the data of Hyvönen et al. (2003) and the experimental results for Fe (Villén et al., 2007) that revealed that EDTA may maintain larger concentrations of micronutrients in nutrient solutions than IDHA. Also in the tomato on rockwool experiment the application of IDHA produces higher increments of SPAD indexes than EDTA, but low differences were found in the micronutrient contents. To explain the reason of these better SPAD index behavior, an attempt to study the micronutrient balances was made using DRIS analysis (Beaufils, 1973) (data not shown). Despite no reliable micronutrient ratio norms, we observed a better balance in IDHA treatment that can explain the better response for this treatment in hydroponics systems than the EDTA.
Plants treated with EDTA were more susceptible to suffer cryptogamic infections than those treated with IDHA. There is extensive literature on the competition for Fe between pathogens and host plants (Neema et al., 1993; Rahman and Punja, 2003). Bienfait et al. (2004) detected the uptake of Fe chelates by different plant species. They observed that cucumber grown on Fe-EDDHA developed a mildew infection, while plants grown in nutrient solution without Fe-EDDHA were not infected. The authors explain their results by two mechanisms: (i) when plants grow on Fe-chelate, a passive influx of Fe which is not under control of the plant's sensing system occurs. In this case an infecting microorganism can obtain sufficient Fe for its growth and (ii) EDDHA or one of its breakdown products can be interfering with the plants' natural resistance against microbial infection. Thus, the infection observed in our green bean experiment can be explained by a larger availability of soluble (chelated) Fe via the transpiration stream that can proportionate Fe for the microbial growth and/or by the presence of the Fe-EDTA chelate which interfered with the natural resistance to the mildew infection. The infection is, however, very low in plants treated with IDHA chelates. Whether IDHA chelates are not able to enter the plant or they are decomposed into the plant cannot be elucidated from the data here presented.
To prevent possible mineral deficiencies, IDHA chelates can be used instead of EDTA chelates in hydroponics and fertigation cultures because they give similar nutritional parameters and fruit yield. The IDHA present an advantage that it is a biodegradable chelate. However its use at high pH conditions or with highly Fe sensitive crops may not be recommended.
|
ACKNOWLEDGMENTS
|
|---|
This study was supported by the proyet AGL2004-07849-C02-01/AGR of the Spanish Ministry of Science and Education and by ADOB Przedsiebiorstwo Produkcyjno-consultingowe.
All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher.
|
REFERENCES
|
|---|
- Álvarez-Fernández, A., S. García-Marco, and J.J. Lucena. 2005. Evaluation of synthetic Iron(III)-chelates (EDDHA/Fe3+, EDDHMA/Fe3+ and EDDHSA/Fe3+) to correct iron chlorosis. Eur. J. Agron. 22:119–130.[CrossRef]
- Álvarez-Fernández, A., A. Pérez-Sanz, and J.J. Lucena. 2001. Evaluation of washing procedures on mineral analysis for orange and peach leaves sprayed with seaweed extracts enriched with iron. Commun. Soil Sci. Plant Anal. 32:157–170.[Web of Science]
- Beaufils, E.R. 1973. Diagnosis and recommendation integrated system (DRIS). Soil Sci. Bull. 1. Univ. of Natal, South Africa.
- Bienfait, H.F., J.M. García-Mina, and A.M. Zamareño. 2004. Distribution and secondary effects of EDDHA in some vegetable species. Soil Sci. Plant Nutr. 50:1103–1110.
- Chen, Y., and P. Barak. 1982. Iron nutrition of plants in calcareous soils. Adv. Agron. 5:217.
- Fernández, V., V. Río, J. Abadía, and A. Abadía. 2006. Foliar iron fertilization of peach (Prunus persica (L.) Batsch): Effects of iron compounds, surfactants and other adjuvants. Plant Soil 289:239–252.[Web of Science]
- García-Marco, S., N. Martínez, F. Yunta, L. Hernández-Apaolaza, and J.J. Lucena. 2006. Effectiveness of Ethylenediamine-N(o-hydroxyphenylacetic)-N'(p-hydroxyphenylacetic) acid (o,p-EDDHA) to supply iron to plants. Plant Soil 279:31–40.[Web of Science]
- Gómez-Gallego, M., M.A. Sierra, R. Alcázar, P. Ramírez, C. Piñar, M.J. Mancheño, S. García-Marco, F. Yunta, and J.J. Lucena. 2002. Synthesis of o,p-EDDHA and its detection as the main impurity in o,o-EDDHA commercial iron chelates. J. Agric. Food Chem. 50:6395–6399.[Web of Science][Medline]
- Gorelov, I.P., V.M. Nikol'skii, A.G. Mukhometzyanov, N.N. Abramovskaya, S.S. Ryasenskii, O.E. Myasnikov, A.V. Pugaev, and L.A. Maiorova. 1987. Dicarboxylic acid derivatives as chelates. Khimiya v Sel'skom Khozyaistve. 1:48–49.
- Hyvönen, H., M. Orama, H. Saarinen, and R. Aksela. 2003. Studies on biodegradable chelating agents: Complexation of iminodisuccinic acid (ISA) with Cu(II), Zn(II), Mn(II) and Fe(III) ions in aqueous solution. Green Chem. 5:410–414.
- Jones, J.B., Jr., B. Wolf, and H. Mills. 1991. Tables of interpretative values. Appendix 1. p. 117–192. In Plant analysis handbook. Micro-Macro Publ., Athens, GA.
- La Malfa, G., and C. Leonardi. 2001. Crop practices and techniques: Trends and needs. Acta Hortic. 559:31–42.
- Lindsay, W.L. 1972. Zinc in soils and plant nutrition. Adv. Agron. 24:147–186.
- Lindsay, W.L. 1979. Chemical equilibria in soils. John Wiley & Sons, New York.
- Lindsay, W.L., and A.P. Schwab. 1982. The chemistry of iron in soils and its availability to plants. J. Plant Nutr. 5:821–840.[Web of Science]
- Lucena, J.J. 2000. Effect of bicarbonate, nitrate and other environmental factors on iron deficiency chlorosis. A review. J. Plant Nutr. 23:1591–1606.
- Mengel, K., E.A. Kirby, H. Kosegarten, and T. Appel. 2001. Iron. p. 553–571. In Principles of plant nutrition. Kluwer Academic, Dordrecht, the Netherlands.
- Mitschker, A., R.J. Moritz, and A. Nawrocki. 2004. Chelated plant micronutrients. Bayer Chemicals A.-G., Germany, Przedsiebiorstwo Produkcyjno-Consultingowe Adob. Eur. Pat. EP 1411037 A1 20040421.
- Neema, C., J.P. Laulhere, and D. Expert. 1993. Iron deficiency induced by chrysobactin in Saintpaulia leaves inoculated with Erwinia chrysanthemi. Plant Physiol. 102:967–973.[Abstract]
- Novack, B., and J.M. Vanbriesen. 2005. Biodegradation of chelating agents: EDTA, DTPA, PDTA, NTA, and EDDS. p. 150–170. In Biogeochemistry of chelating agents. ACS Symp. Ser. 910. Am. Chemical Soc., Washington, DC.
- Papadopoulos, P., and D.L. Rowell. 1989. The reactions of copper and zinc with calcium carbonate surfaces. J. Soil Sci. 40:39–48.
- Rahman, M., and Z.K. Punja. 2003. Growth of Cylindrocarpon destructans and interactions with ginseng roots to cause root rot. Can. J. Plant Pathol. 25:112.
- Schlegel, T.K., J. Schoenherr, and L. Schreiber. 2006. Rates of foliar penetration of chelated Fe(III): Role of light, stomata, species, and leaf age. J. Agric. Food Chem. 54:6809–6813.[Web of Science][Medline]
- Uygur, V., and D.L. Rimmer. 2000. Reactions of zinc with iron coated calcite surfaces at alkaline pH. Eur. J. Soil Sci. 51:511–516.[CrossRef]
- Villén, M., A. García-Arsuaga, and J.J. Lucena. 2007. Potential use of biodegradable chelate N-(1,2-Dicarboxyethyl)-D,L-aspartic Acid/Fe3+ as an Fe Fertilizer. J. Agric. Food Chem. 55:402–407.[Web of Science][Medline]
TOP
ABSTRACT
INTRODUCTION
