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A partir de resultados de um experimento de campo com arranjo fatorial, no qual foi estudada a resposta à aplicação de N e K em bananeira, em dois ciclos de cultivo, avaliou-se o desempenho do diagnóstico nutricional para esses nutrientes, empregando-se o sistema integrado de diagnose e recomendação (DRIS) e o critério de níveis críticos (NC). As situações nas quais se diagnosticou deficiência, foram classificadas como positivas (+), aquelas cujo diagnóstico indicou suficiência, como negativas (-). Em função da resposta na produção de frutos à aplicação de N ou K, classificaram-se os diagnósticos como verdadeiros (V) ou falsos (F), resultando nas quatro possibilidades V+, V-, F+ e F-. Em relação ao N, a eficiência (%V+ e %V-) dos diagnósticos baseados em NC foi de 48%; com o DRIS, foi de 69%. Para K, a eficiência dos diagnósticos feitos a partir do DRIS e NC foi de 63%. A proporção de diagnósticos de deficiência que se confirmaram com respostas positivas à aplicação de N em relação aos falsos positivos (%V+¸%F+), foi de 1,50 para o DRIS e de 0,68 para NC. Para os diagnósticos de deficiência de K, essa proporção foi de 1,67 para DRIS e NC. A variação líquida no rendimento (48 casos) decorrente da aplicação de N associada a diagnósticos corretos foi de 124 t ha¹ para o DRIS e de 20 t ha¹ para NC. Para K, essa variação foi de 70 t ha¹ para o DRIS e NC.The Performance of DRIS and critical value approach (CVA) diagnostics were evaluated based on leaf analysis from a field experiment on a factorial design to study the yield response of banana to N and K applications during two crop seasons. The situations identified as deficient were classified as positives (+) and those diagnosed as sufficient, were classified as negatives (-). According to the response on yield due the application of N or K, the diagnostics were classified as true (V) or false (F). Four combinations were possible: V+, V-, F+ and F-. The efficiency for N diagnostics (%V+ and %V-) based on the critical value approach was 48%, while using the DRIS it was 69%. The efficiency for K diagnostics was 63% for both DRIS and CV methods. The relation between deficient diagnostics confirmed by positive response on yield under application of the nutrient and false positive cases (%V+¸%F+) for N was 1.5 for the DRIS and 0.68 for CVA. For the K deficiency diagnostics, the value of this relation was 1.67 for both methods. The net yield derived from N application based on correct diagnostics (48 cases) was 124 Mg ha-1 for DRIS and 20 Mg ha-1 for the CVA. For K, this variation was 70 Mg ha-1 for the DRIS and the CVA.

A partir de resultados de um experimento de campo com arranjo fatorial, no qual foi estudada a resposta à aplicação de N e K em bananeira, em dois ciclos de cultivo, avaliou-se o desempenho do diagnóstico nutricional para esses nutrientes, empregando-se o sistema integrado de diagnose e recomendação (DRIS) e o critério de níveis críticos (NC). As situações nas quais se diagnosticou deficiência, foram classificadas como positivas (+), aquelas cujo diagnóstico indicou suficiência, como negativas (-). Em função da resposta na produção de frutos à aplicação de N ou K, classificaram-se os diagnósticos como verdadeiros (V) ou falsos (F), resultando nas quatro possibilidades V+, V-, F+ e F-. Em relação ao N, a eficiência (%V+ e %V-) dos diagnósticos baseados em NC foi de 48%; com o DRIS, foi de 69%. Para K, a eficiência dos diagnósticos feitos a partir do DRIS e NC foi de 63%. A proporção de diagnósticos de deficiência que se confirmaram com respostas positivas à aplicação de N em relação aos falsos positivos (%V+¸%F+), foi de 1,50 para o DRIS e de 0,68 para NC. Para os diagnósticos de deficiência de K, essa proporção foi de 1,67 para DRIS e NC. A variação líquida no rendimento (48 casos) decorrente da aplicação de N associada a diagnósticos corretos foi de 124 t ha¹ para o DRIS e de 20 t ha¹ para NC. Para K, essa variação foi de 70 t ha¹ para o DRIS e NC. The Performance of DRIS and critical value approach (CVA) diagnostics were evaluated based on leaf analysis from a field experiment on a factorial design to study the yield response of banana to N and K applications during two crop seasons. The situations identified as deficient were classified as positives (+) and those diagnosed as sufficient, were classified as negatives (-). According to the response on yield due the application of N or K, the diagnostics were classified as true (V) or false (F). Four combinations were possible: V+, V-, F+ and F-. The efficiency for N diagnostics (%V+ and %V-) based on the critical value approach was 48%, while using the DRIS it was 69%. The efficiency for K diagnostics was 63% for both DRIS and CV methods. The relation between deficient diagnostics confirmed by positive response on yield under application of the nutrient and false positive cases (%V+¸%F+) for N was 1.5 for the DRIS and 0.68 for CVA. For the K deficiency diagnostics, the value of this relation was 1.67 for both methods. The net yield derived from N application based on correct diagnostics (48 cases) was 124 Mg ha-1 for DRIS and 20 Mg ha-1 for the CVA. For K, this variation was 70 Mg ha-1 for the DRIS and the CVA.

Summary Soil and plant testing programs are still based on ‘trial and error’ methods and lack scientific underpinning in terms of relevant soil chemical and plant nutritional processes, and are site-specific. The programs are valuable when the objective is to diagnose and predict deficiencies of plant nutrients. The programs are less valuable for refined fertilizer strategies, like Integrated Nutrient Management, which are essential in the near future to satisfy changing agricultural, environmental, economic and legislative boundary conditions. A more scientific approach to soil and plant testing programs appears desirable. To reduce undesirable side-effects of fertilization on the environment, more emphasis should be placed on fertilizer type and on timing and method of application.

Gedurende de afgelopen jaren is de teelt van Phalaenopsis versneld door het toelaten van meer licht en met hogere vochtigheden tijdens de teelt. Hiermee staan ziekten en plagen zoals Fusarium, Pseudomonas, Erwinia of potworm op de loer waardoor de vraag naar weerbaarheid van het gewas groter wordt. Dit project beoogd antwoord te geven op de vraag of de weerbaarheid van Phalaenopsis verhoogd kan worden door een uitgebalanceerde voeding.

Gedurende de afgelopen jaren is de teelt van Phalaenopsis versneld door het toelaten van meer licht en met hogere vochtigheden tijdens de teelt. Hiermee staan ziekten en plagen zoals Fusarium, Pseudomonas, Erwinia of potworm op de loer waardoor de vraag naar weerbaarheid van het gewas groter wordt. Dit project beoogd antwoord te geven op de vraag of de weerbaarheid van Phalaenopsis verhoogd kan worden door een uitgebalanceerde voeding.

TEZ8924 Tez (Doktora) -- Çukurova Üniversitesi, Adana, 2013. Kaynakça (s. 93-108) var. xi, 131 s. : res. ; 29 cm. In this study, wastewater based on today's increasing urbanization, the increasing discharge of it, by treatment and mixing equal amounts for reuse in agricultural production have been assessed. The content of water used in the trial were examined according to ,the during irrigation season and pH, EC, SAR, TSS, COD, BOD5, Total Nitrogen and Phosphorus contents, and Fecal Coliform, Cd values were not possible to the reuse. Also concluded that significantly changed the flowering time and the vegetation period on plant development of maize. Low harvest index and high dry matter production have been identified by reuse waste water and its versions. Yield components as ear length and ear width and TKW were not affected by use wastewater and water, which waste water source. The yield and the number of grain on ear of yield components are the same by use urban wastewater and clean water, and are low by the use of treated water. According to plant analysis, the use of urban wastewater increased during the harvest period, amounts of N in the all plant organs, amounts of P in roots and grain, amounts of K in roots, amounts of Ca in trunk, leaves and grain, amounts of Mg in roots and grain. While the amounts of Fe, Zn, Cu increased in the all plant organs. The amounts of Mn only increased in the trunk and leaves. Although low amounts of Pb and Ni contents, tended to accumulate in the plant to the continuity of the use of wastewater, Cd content was found high amounts of the plant. The amounts of B and Al increased in leaves. Water used for the experiment showed a slight decrease in the soil pH, in the EC increased amounts of lime and organic matter has not changed. N, P, K, Zn, Mn and B contents and the number of TFK increased in the soil. Fe, Cu, Ni and Pb contents have not changed. The conclusion has been reached that maize can be grown using waste water in agriculture but significantly would affect without controlling of the heavy metal treatment, salinity and wastewater management because of microbiological treatment the rate of microbial contamination and sustainability of pollution. Bu çalışmanın amacı, günümüzde artan kentleşmeye bağlı olarak deşarjı da artan atık suların arıtılarak ve seyreltilerek bitkisel üretimde yeniden değerlendirilmesine yöneliktir. Denemede kullanılan suların içerikleri incelenmiş; pH, EC, SAR, AKM, KOİ, BOİ5, Toplam N ve P içerikleri ve TFK, Cd değerlerinden dolayı kullanımının mümkün olmadığı görülmüştür. Mısır bitkisinin gelişiminde; çiçeklenme süresinin ve vejetasyon süresinin önemli ölçüde değiştiği, hasat indeksinin düştüğü, kuru madde üretiminin yükseldiği ve koçan boyu, koçan eni ve BDA gibi verim unsurlarının etkilenmediği sonucu saptanmıştır. Verim ve koçanda dane sayısı kentsel atık su ve temiz su kullanımıyla aynı iken, arıtılmış su kullanımı ile düşmüştür. Bitki analizlerinde kentsel atık su kullanımının N içeriğini kök, toprak üstü aksan ve danede, P içeriğini kök ve danede, K içeriğini kökte Ca içeriğini toprak üstü aksan ve danede, Mg içeriğini kök ve danede artırdığı saptanmıştır. Fe, Zn, Cu içerikleri kök, gövde yaprak ve danede atık su kullanımı ile artarken Mn içeriği, sadece toprak üstü aksanda artmıştır. Pb ve Ni içerikleri düşük miktarda olmakla, atık su kullanımının sürekliliği ile bitkide birikme eğilimi gösterirken, Cd içeriği, bitkide yüksek miktarda saptanmıştır. B ve Al içerikleri ise yapraklarda yüksektir. Deneme topraklarında atık su ve atık su kaynaklı suların kullanımı ile toprakta pH hafif azalış gösterirken, EC artmış, kireç ve organik madde miktarları değişmemiştir. Toprakların N, P, K, Zn, Mn ve B içerikleri ve TFK sayısı artarken, Fe, Cu, Ni ve Pb içerikleri değişmemiştir. Çalışmada kentsel atık su ve kentsel atık suların arıtılarak ve seyreltilerek mısır bitkisinin yetiştiriciliğinde kullanılabileceği sonucuna varılmıştır. Ancak, tuzluluk kontrolü, mikrobiyolojik arıtım ve ağır metal arıtımı yapılmadan, atık ve atık su kaynaklı karışımların kullanılması, toprakların çoraklaşmasını ve mikrobiyal kirlenme oranını ve kirlenmenin sürekliliğini önemli ölçüde etkileyeceği sonucuna ulaşılmıştır. Bu çalışma Ç.Ü. Bilimsel Araştırma Projeleri Birimi tarafından desteklenmiştir. Proje No: ZF2005D5.

The molecular composition of organic matter in peatlands reflects local conditions and stores information about botanical composition (plant source) as well as the degree of and conditions during decomposition. A reliable hydrological (and hence palaeoclimatological) interpretation of source and decomposition proxies in peatlands requires the understanding of the interactions between decomposition and botanical composition and the reaction of both to changes in the water table. Only few studies combined vegetation and decomposition characteristics to investigate peat OM dynamics and reconstruct environmental changes, and these included only a limited number of samples. In order to study the three-way relationship between botanical composition, decomposition and environmental conditions, pyrolysis-GC/MS of high-resolution sampled peat cores was used on two contrasting ombrotrophic peatlands. The two sites comprise a Sphagnum-dominated peatland in Tierra del Fuego (Argentina) and a graminoid-dominated peatland in Galicia (Spain). The purpose of this study was to examine the use of analytical pyrolysis in the environmental interpretation of peat profiles and to gain an improved understanding of peat OM dynamics and thereby develop parameters that reliably reflect past environmental conditions.The molecular composition of the Sphagnum-dominated Harberton peatland was first explored for a selection of samples. Several peat fractions have been analysed, including NaOH-extract, NaOH-insoluble residue and bulk sample. A large number of pyrolysis products was identified and quantified for all peat samples; additionally total C, N and ash content were measured. Molecular parameters were identified by a systematic methodological approach. Peatland plants have been analysed in search for specific markers. Factor analysis was used to reduce the number of pyrolysis products for quantification and to assess differences in peat chemistry and relate these to environmental factors. This resulted in a number of molecular parameters that reflect botanical changes, (an)aerobic decomposition and fire incidence.The results of the different peat fractions and plant analysis were applied to a large number of bulk samples (67), and used to reconstruct the 12,000 years of vegetation history of the Harberton core, which was then interpreted in terms of past hydrological conditions. The C:N ratio showed a perfect agreement with the botanical composition according to pyrolytic plant markers. It appeared that the n-alkane distribution showed remarkable changes with respect to shifts in the abundance of Sphagnum. Consequently, the detailed vegetation reconstruction was used to discuss the application of the n-alkane distribution in ombrotrophic peat. The simultaneous effects of botanical shifts (source material) and decomposition may cause conflicting hydrological interpretations for non-specific plant markers such as n-alkanes. The results indicated a considerable effect of aerobic decomposition on the distribution of n-alkanes. Although pyrolysis is not the regular method to establish the n-alkane distribution, comparison of n-alkanes in the NaOH-extract and residue peat samples supported the findings. The results emphasise the importance of combining vegetation and decomposition characteristics.For the graminoid-dominated Penido Vello peatland, all 101 bulk peat samples of the 3 m thick peat deposit have been analysed. In addition to the search for specific compounds of peatland plants, the same pyrolysis products were quantified for plant pyrolysates and peat. Depth records of plant markers agreed well with their preferential habitat, with the degree of decomposition and with the transition from minerotrophic to ombrotrophic peat. Factor analysis was used to reconstruct past hydrology. The results showed the importance of high-resolution sampling through the higher correlations between molecular parameters in the part sampled each 2 cm compared to 5 cm. Furthermore, good correlations of pyrolysis results were found with mineral content, solid-state 13C CPMAS NMR data and total N.The hydrological reconstruction based on depth records of plant markers and factor scores obtained by factor analysis of all quantified pyrolysis products, and the low contribution of Sphagnumto the graminoid-dominated Penido Vello peat allowed studying the effects of source and decay on the lignin composition. A large number of lignin pyrolysis products were quantified for peatland plants and for the three different peat fractions for a selection of 15 samples. Lignin composition of woody and graminoid plant species were compared as well as the lignin composition in different peat fractions, and their relation to source or decay was established.To determine whether the lignin parameters, derived from analysis of plants and peat fractions, can be used to reconstruct peat environment, they were applied to all 51 bulk peat samples of the upper meter of the Penido Vello core. The results show a strong effect of vegetation type and anaerobicity on generally-used lignin decomposition proxies, which indicates that such proxies are not reliable without information on the context.To examine the interaction between vegetation type and decomposition processes, the results of Sphagnum-dominated peat and graminoid-dominated peat were combined. In addition to the well-known pyrolytic marker from Sphagnum (4-isopropenylphenol), depth records of pyrolysis products specific for lichens and graminoids functioned well in both peatlands and are considered reliable markers for application in other peatlands. A number of other identified markers only functioned well within one of both peatlands. The different functioning of these markers in the two peatlands emphasises the importance of plant analysis prior to the use of pyrolytic biomarkers with low specificity, but also shows that supposedly non-specific pyrolysis products can be specific within a certain peatland ecosystem. The use of different peat fractions (NaOH-extractable and non-extractable peat) provided information on the degree of decomposition and allowed comparison with studies on peat humic acids and humin, and the generally applied colorimetric method to determine peat humification. Furthermore, the comparison of pyrolysates of extracts and residues for a selection of peat samples, in combination with factor analysis, allowed separation of the effects of source, and several stages of aerobic and anaerobic decay. Degradation of lignin-cellulose (vascular plants) and polyphenol-cellulose (Sphagnum) is discussed using the abundance of their markers (lignin moieties, levoglucosan and 4-isopropenylphenol) in pyrolysates of the different peat fractions, and gives insight into degradation mechanisms. The results indicated that, in Sphagnum litter, polyphenols are more easily degraded than polysaccharides. Comparison of pyrolysis results and C:N ratio showed that differences in litter quality between Sphagnum and vascular plants is a major factor that determines the variance of C:N with depth. Large part of the variation in C:N in Sphagnum-dominated peat is caused by decomposition rather than small increases of vascular plants upon drier conditions, while in graminoid-dominated peat this is not true and several processes may disturb the effect of mass loss on the C:N ratio. The C:N ratio can thus be a consistent decomposition proxy in Sphagnum-dominated peat but not in graminoid-dominated peat. Pyrolysis-GC/MS in combination with the applied research design provided detailed chemical information that gave insight in both vegetation and decomposition characteristics. This methodology thus has a high potential for the reconstruction of past environmental conditions.

The molecular composition of organic matter in peatlands reflects local conditions and stores information about botanical composition (plant source) as well as the degree of and conditions during decomposition. A reliable hydrological (and hence palaeoclimatological) interpretation of source and decomposition proxies in peatlands requires the understanding of the interactions between decomposition and botanical composition and the reaction of both to changes in the water table. Only few studies combined vegetation and decomposition characteristics to investigate peat OM dynamics and reconstruct environmental changes, and these included only a limited number of samples. In order to study the three-way relationship between botanical composition, decomposition and environmental conditions, pyrolysis-GC/MS of high-resolution sampled peat cores was used on two contrasting ombrotrophic peatlands. The two sites comprise a Sphagnum-dominated peatland in Tierra del Fuego (Argentina) and a graminoid-dominated peatland in Galicia (Spain). The purpose of this study was to examine the use of analytical pyrolysis in the environmental interpretation of peat profiles and to gain an improved understanding of peat OM dynamics and thereby develop parameters that reliably reflect past environmental conditions.The molecular composition of the Sphagnum-dominated Harberton peatland was first explored for a selection of samples. Several peat fractions have been analysed, including NaOH-extract, NaOH-insoluble residue and bulk sample. A large number of pyrolysis products was identified and quantified for all peat samples; additionally total C, N and ash content were measured. Molecular parameters were identified by a systematic methodological approach. Peatland plants have been analysed in search for specific markers. Factor analysis was used to reduce the number of pyrolysis products for quantification and to assess differences in peat chemistry and relate these to environmental factors. This resulted in a number of molecular parameters that reflect botanical changes, (an)aerobic decomposition and fire incidence.The results of the different peat fractions and plant analysis were applied to a large number of bulk samples (67), and used to reconstruct the 12,000 years of vegetation history of the Harberton core, which was then interpreted in terms of past hydrological conditions. The C:N ratio showed a perfect agreement with the botanical composition according to pyrolytic plant markers. It appeared that the n-alkane distribution showed remarkable changes with respect to shifts in the abundance of Sphagnum. Consequently, the detailed vegetation reconstruction was used to discuss the application of the n-alkane distribution in ombrotrophic peat. The simultaneous effects of botanical shifts (source material) and decomposition may cause conflicting hydrological interpretations for non-specific plant markers such as n-alkanes. The results indicated a considerable effect of aerobic decomposition on the distribution of n-alkanes. Although pyrolysis is not the regular method to establish the n-alkane distribution, comparison of n-alkanes in the NaOH-extract and residue peat samples supported the findings. The results emphasise the importance of combining vegetation and decomposition characteristics.For the graminoid-dominated Penido Vello peatland, all 101 bulk peat samples of the 3 m thick peat deposit have been analysed. In addition to the search for specific compounds of peatland plants, the same pyrolysis products were quantified for plant pyrolysates and peat. Depth records of plant markers agreed well with their preferential habitat, with the degree of decomposition and with the transition from minerotrophic to ombrotrophic peat. Factor analysis was used to reconstruct past hydrology. The results showed the importance of high-resolution sampling through the higher correlations between molecular parameters in the part sampled each 2 cm compared to 5 cm. Furthermore, good correlations of pyrolysis results were found with mineral content, solid-state 13C CPMAS NMR data and total N.The hydrological reconstruction based on depth records of plant markers and factor scores obtained by factor analysis of all quantified pyrolysis products, and the low contribution of Sphagnumto the graminoid-dominated Penido Vello peat allowed studying the effects of source and decay on the lignin composition. A large number of lignin pyrolysis products were quantified for peatland plants and for the three different peat fractions for a selection of 15 samples. Lignin composition of woody and graminoid plant species were compared as well as the lignin composition in different peat fractions, and their relation to source or decay was established.To determine whether the lignin parameters, derived from analysis of plants and peat fractions, can be used to reconstruct peat environment, they were applied to all 51 bulk peat samples of the upper meter of the Penido Vello core. The results show a strong effect of vegetation type and anaerobicity on generally-used lignin decomposition proxies, which indicates that such proxies are not reliable without information on the context.To examine the interaction between vegetation type and decomposition processes, the results of Sphagnum-dominated peat and graminoid-dominated peat were combined. In addition to the well-known pyrolytic marker from Sphagnum (4-isopropenylphenol), depth records of pyrolysis products specific for lichens and graminoids functioned well in both peatlands and are considered reliable markers for application in other peatlands. A number of other identified markers only functioned well within one of both peatlands. The different functioning of these markers in the two peatlands emphasises the importance of plant analysis prior to the use of pyrolytic biomarkers with low specificity, but also shows that supposedly non-specific pyrolysis products can be specific within a certain peatland ecosystem. The use of different peat fractions (NaOH-extractable and non-extractable peat) provided information on the degree of decomposition and allowed comparison with studies on peat humic acids and humin, and the generally applied colorimetric method to determine peat humification. Furthermore, the comparison of pyrolysates of extracts and residues for a selection of peat samples, in combination with factor analysis, allowed separation of the effects of source, and several stages of aerobic and anaerobic decay. Degradation of lignin-cellulose (vascular plants) and polyphenol-cellulose (Sphagnum) is discussed using the abundance of their markers (lignin moieties, levoglucosan and 4-isopropenylphenol) in pyrolysates of the different peat fractions, and gives insight into degradation mechanisms. The results indicated that, in Sphagnum litter, polyphenols are more easily degraded than polysaccharides. Comparison of pyrolysis results and C:N ratio showed that differences in litter quality between Sphagnum and vascular plants is a major factor that determines the variance of C:N with depth. Large part of the variation in C:N in Sphagnum-dominated peat is caused by decomposition rather than small increases of vascular plants upon drier conditions, while in graminoid-dominated peat this is not true and several processes may disturb the effect of mass loss on the C:N ratio. The C:N ratio can thus be a consistent decomposition proxy in Sphagnum-dominated peat but not in graminoid-dominated peat. Pyrolysis-GC/MS in combination with the applied research design provided detailed chemical information that gave insight in both vegetation and decomposition characteristics. This methodology thus has a high potential for the reconstruction of past environmental conditions.

De werking is getest van een flexibel geautomatiseerd meet- en regelsysteem voor de ammoniumgift (afhankelijk van de pH van de drain). Het effect is van de verhoogde ammoniumgift op de pH, de gewassamenstelling en gewasproductie is gemeten.

Fertilisers received a lot of attention when growers first started using substrates. Since then the nutritional requirements of the plant have been largely driven by the need to reduce runoff emissions. In addition, more efficient use of fertilisers is playing a role. Until now growers went along with standerd fertiliser strategies. Now they are starting to adjust the nutrients given to suit the plant's needs.

In de jaren 2003 tot 2007 is het aantal bedrijven waarop (semi)gesloten geteeld wordt geleidelijk toegenomen. Op alle bedrijven bleken echter vragen te bestaan over de reacties van het gewas op het nieuwe klimaat. Daarom is in 2008 door Wageningen UR Glastuinbouw een onderzoek gestart naar de groei van tomaat in geconditioneerde kassen, waarin veel aandacht wordt besteed aan de fysiologische processen in de plant. Het onderzoek wordt gefinancierd vanuit het programma Kas als Energiebron door Productschap Tuinbouw en het ministerie van EL&I en wordt begeleid door een aantal tomatentelers en een adviseur. Het onderzoek dat in dit rapport wordt beschreven had als centrale vragen hoe verschillende temperatuurstrategieën de processen in de plant beïnvloeden en hoe CO2 in de kas efficiënt benut kan worden.

In de jaren 2003 tot 2007 is het aantal bedrijven waarop (semi)gesloten geteeld wordt geleidelijk toegenomen. Op alle bedrijven bleken echter vragen te bestaan over de reacties van het gewas op het nieuwe klimaat. Daarom is in 2008 door Wageningen UR Glastuinbouw een onderzoek gestart naar de groei van tomaat in geconditioneerde kassen, waarin veel aandacht wordt besteed aan de fysiologische processen in de plant. Het onderzoek wordt gefinancierd vanuit het programma Kas als Energiebron door Productschap Tuinbouw en het ministerie van EL&I en wordt begeleid door een aantal tomatentelers en een adviseur. Het onderzoek dat in dit rapport wordt beschreven had als centrale vragen hoe verschillende temperatuurstrategieën de processen in de plant beïnvloeden en hoe CO2 in de kas efficiënt benut kan worden.

A field experiment was carried out on an Ultisol located at the city of Agudos (22º30'S; 49º03'W), in the state of São Paulo, Brazil, in order to determine the effects of rates and sources of potassium fertilizer on nutritional status of 'Smooth Cayenne' pineapple and on some soil chemical properties. The experiment was a complete factorial design with four rates (0, 175, 350, and 700 kg ha-1 of K2O) and three combinations of K sources (100% KCl, 100% K2SO4 and 40% K2SO4 + 60% KCl). Soil samples were taken from the depths 0-20 cm, 20-40 cm and 40-60 cm at planting and 14 months after. Nutritional status of pineapple plants was assessed by means of tissue analysis. Soil K availability increased with application of K fertilizer, regardless of K sources. Soil chlorine and Cl concentration in pineapple leaves increased with application of KCl or K2SO4+KCl. Plant uptake of potassium was shaped by soil K availability and by the application rates of K fertilizer, independently of K sources. Foi realizado um experimento de campo num Argissolo Vermelho-Amarelo, em Agudos-SP (22º30'S; 49º03'W), com o objetivo de determinar os efeitos de fontes e doses de fertilizante potássico no estado nutricional de abacaxi 'Smooth Cayenne' e em alguns atributos químicos do solo. Empregou-se um arranjo fatorial com quatro doses (0; 175; 350 e 700 kg ha-1 de K2O) e três combinações de fontes (100% KCl, 100% K2SO4 e 40% K2SO4 + 60% KCl). A amostragem de solo foi realizada nas camadas de 0 a 20 cm, 20 a 40 cm e de 40 a 60 cm na época do plantio e 14 meses depois. O estado nutricional dos abacaxizeiros foi avaliado por meio de análise foliar. A disponibilidade de K no solo aumentou em função das doses, independentemente da fonte empregada. A concentração de cloro no solo e seu teor nas folhas de abacaxizeiro cresceram com a aplicação de KCl e de K2SO4+KCl. A absorção de potássio pelo abacaxizeiro apresentou correlação significativa com as doses de K aplicadas, independentemente da fonte.

A field experiment was carried out on an Ultisol located at the city of Agudos (22º30'S; 49º03'W), in the state of São Paulo, Brazil, in order to determine the effects of rates and sources of potassium fertilizer on nutritional status of 'Smooth Cayenne' pineapple and on some soil chemical properties. The experiment was a complete factorial design with four rates (0, 175, 350, and 700 kg ha-1 of K2O) and three combinations of K sources (100% KCl, 100% K2SO4 and 40% K2SO4 + 60% KCl). Soil samples were taken from the depths 0-20 cm, 20-40 cm and 40-60 cm at planting and 14 months after. Nutritional status of pineapple plants was assessed by means of tissue analysis. Soil K availability increased with application of K fertilizer, regardless of K sources. Soil chlorine and Cl concentration in pineapple leaves increased with application of KCl or K2SO4+KCl. Plant uptake of potassium was shaped by soil K availability and by the application rates of K fertilizer, independently of K sources.

Bij de introductie van de eerste substraten kreeg de bemesting veel belangstelling. Daarna bleef de behoefte van de plant aan voedingsstoffen lange tijd onderbelicht. Nu is er sprake van een revival. Verlaging van de emissies is een motor achter de hernieuwde belangstelling. Maar een effectiever gebruik van meststoffen begint ook mee te spelen. Tot nu toe voorzagen de telers het systeem van meststoffen. Nu beginnen ze de voedingsgift op de plant af te stemmen.

Bij de introductie van de eerste substraten kreeg de bemesting veel belangstelling. Daarna bleef de behoefte van de plant aan voedingsstoffen lange tijd onderbelicht. Nu is er sprake van een revival. Verlaging van de emissies is een motor achter de hernieuwde belangstelling. Maar een effectiever gebruik van meststoffen begint ook mee te spelen. Tot nu toe voorzagen de telers het systeem van meststoffen. Nu beginnen ze de voedingsgift op de plant af te stemmen.

In proeven op vier locaties met verschillende tarwerassen onderzocht PPO de werking van de chlorophylmeter, waarmee de groenheid van een tarwegewas wordt vastgesteld en vervolgens daarmee de stikstofbemesting wordt afgestemd op de behoefte. Met het systeem blijkt het goed mogelijk de optimale tweede en derde stikstofgift te bepalen (resp. aan het begin van de strekkingsfase en bij het in aar komen)

Para estimativa da demanda de micronutrientes pela bananeira (Musa spp.) é fundamental que se conheçam as quantidades de matéria seca e de micronutrientes acumuladas na planta e exportadas pelo cacho. Neste trabalho, objetivou-se avaliar o acúmulo de matéria seca e de micronutrientes em seis variedades de bananeira sob irrigação. Foram amostradas plantas das variedades Grande Naine, Pacovan, Pacovan-Apodi, Prata-Anã, Terrinha e Gross Michel. As variedades foram plantadas em fileiras duplas, sendo 1.666 covas por hectare. Na época da colheita, foram escolhidas quatro touceiras de plantas de cada variedade para amostragem da planta-mãe, que foi dividida em rizoma, pseudocaule, pecíolo, limbo, engaço e frutos. Foram feitas pesagens para a determinação da matéria fresca de cada parte da planta-mãe de uma mesma touceira e retirada uma amostra de aproximadamente 700 g dessas partes para determinação do acúmulo de matéria seca e dos teores de micronutrientes. As amostras foram lavadas rapidamente com água de torneira, depois com água destilada e colocadas sobre as bancadas de uma casa de vegetação para pré-secagem. Posteriormente, foram colocadas em sacos de papel e levadas para uma estufa de circulação forçada de ar para obtenção do acúmulo de matéria seca e determinação dos teores de B, Cu, Fe, Mn e Zn. As variedades Pacovan, Prata Anã e Pacovan-Apodi acumularam maiores quantidades de matéria seca e de micronutrientes, quando comparadas com as variedades Grande Naine, Gross Michel e Terrinha, sendo a seguinte ordem decrescente de acúmulo e de exportação de micronutrientes: Mn > Fe > B > Zn > Cu. To estimate the demand of micronutrients for the banana plants (Musa spp.), it is essential to know the amounts of dry matter and micronutrients accumulated in the plant and exported by the bunch. The objective of this study was to evaluate the accumulation of dry matter and micronutrients by six banana varieties under irrigation. Plants of Grande Naine, Pacovan, Pacovan-Apodi, Prata-Anã, Terrinha and Gross Michel varieties grown in double rows, with a density equivalent to 1,666 plants per hectare were sampled. At harvest four plants of each variety were selected for sampling of mother-plant, which was divided into rhizome, pseudostem, petiole, leaf blade, stalk and fruits. The plant parts were weighed to determine the fresh weight of each part and a sample of about 700 g of each part was collected to determine dry weight and contents of micronutrients. The samples were washed quickly with tap water and later with distilled water and placed in a greenhouse for pre-drying and afterwards conditioned in paper bags were put in an oven of forced circulation of air for obtaining the dry matter and subsequent determination of the contents of B, Cu, Fe, Mn and Zn. The varieties Pacovan, Prata Anã e Pacovan Apodi accumulated greater amounts of dry matter and micronutrients, when compared to the varieties Grande Naine, Gross Michel e Terrinha, observing the following decreasing order of accumulation and export of micronutrients: Mn > Fe > B > Zn > Cu.

In het project Business Intelligence (BI) in de Sierteelt, dat ingediend is bij Pieken in de Delta Zuidvleugel in 2006, staat de uitwisseling van operationele gegevens tussen partners in de keten (ketentransparantie) en het intelligente gebruik daarvan voor verbetering van de bedrijfsvoering op keten niveau centraal. Het doel van het project was om een theoretisch kader en praktische tools te ontwikkelen voor het intelligent gebruiken van operationele gegevens in de sierteelt. In dit rapport wordt een beschrijving gegeven over de ontwikkelingen met betrekking tot BI in de theorie en de praktijk waarbij vanuit diverse invalshoeken is gewerkt. Daarnaast is in het project aandacht besteed aan het operationeel maken van het gedachtegoed van operationele BI. Dat heeft zijn vorm gevonden in een blauwdruk voor de aanpak van BI projecten in de sector en een beschrijving van een uitgevoerd pilotproject. Uit de studie komt naar voren dat operationele BI waardevol is voor de verbetering van de bedrijfsvoering op ketenniveau en dat een (her)bruikbare blauwdruk is ontwikkeld.

In het project Business Intelligence (BI) in de Sierteelt, dat ingediend is bij Pieken in de Delta Zuidvleugel in 2006, staat de uitwisseling van operationele gegevens tussen partners in de keten (ketentransparantie) en het intelligente gebruik daarvan voor verbetering van de bedrijfsvoering op keten niveau centraal. Het doel van het project was om een theoretisch kader en praktische tools te ontwikkelen voor het intelligent gebruiken van operationele gegevens in de sierteelt. In dit rapport wordt een beschrijving gegeven over de ontwikkelingen met betrekking tot BI in de theorie en de praktijk waarbij vanuit diverse invalshoeken is gewerkt. Daarnaast is in het project aandacht besteed aan het operationeel maken van het gedachtegoed van operationele BI. Dat heeft zijn vorm gevonden in een blauwdruk voor de aanpak van BI projecten in de sector en een beschrijving van een uitgevoerd pilotproject. Uit de studie komt naar voren dat operationele BI waardevol is voor de verbetering van de bedrijfsvoering op ketenniveau en dat een (her)bruikbare blauwdruk is ontwikkeld.

Total concentration is not a reliable indicator of metal phytoavailability in soils. There is a dearth of single universal multielement methods with critical value. Therefore, this study was implemented to select appropriate methods for evaluation of phytoavailable metal status in peaches grown in alkaline alluvial soils. Component plant parts (leaf and fruit flesh and peel) and soil samples were collected from 21 orchards. Fourteen extraction methods were applied to the soils to determine the phytoavailable metal content of the soils. Metal [iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), chromium (Cr), nickel (Ni), cobalt (Co), lead (Pb), and cadmium (Cd)] concentrations in leaf, flesh, and peel samples were assayed, and the relationship was investigated among metals in component parts of the plant. Metals were assayed by various methods to select the most representative method. The methods of aqua regia, Morgan extraction solution, ammonium acetate (NH4OAc; pH4.8), 0.01M disodium ethylenediamine-di-o-hydroxyphenylacetic acid (Na2EDDHA), and sodium acetate (NaOAc) + diethylenetriaminepentaacetic acid (DTPA) for Fe and DTPA + triethanolamine (TEA) + calcium chloride (CaCl2), 0.05 N hydrochloric acid (HCl) + 0.025 N sulfuric acid (H2SO4), NH4OAc (pH4.8), 0.05M ethylenediaminetetraacetic acid (EDTA; pH7.0), 0.01M Na2EDDHA, and 1M ammonium bicarbonate (NH4HCO3) + 0.005M DTPA for Ni were well correlated to Fe and Ni in the leaves, respectively. The main factors affecting Fe and Ni availability in the soils were compared with the other methods. Therefore, based on this study, 0.01M Na2EDDHA should be used for determination of phytoavailable Fe and Ni status in peaches grown on alkaline alluvial soils. Poor correlation was found among the rest of the metals assayed by the methods, concentrations of these metals in component parts of the peach trees, and the examined soil properties. Metal content of the flesh had low correlation coefficients with the examined properties.

article i nfo A simultaneous optimization strategy based on a neuro-genetic approach is proposed for selection of laser induced breakdown spectroscopy operational conditions for the simultaneous determination of macro- nutrients (Ca, Mg and P), micro-nutrients (B, Cu, Fe, Mn and Zn), Al and Si in plant samples. A laser induced breakdown spectroscopy system equipped with a 10 Hz Q-switched Nd:YAG laser (12 ns, 532 nm, 140 mJ) and an Echelle spectrometer with intensified coupled-charge device was used. Integration time gate, delay time, amplification gain and number of pulses were optimized. Pellets of spinach leaves (NIST 1570a) were employed as laboratory samples. In order to find a model that could correlate laser induced breakdown spectroscopy operational conditions with compromised high peak areas of all elements simultaneously, a Bayesian Regularized Artificial Neural Network approach was employed. Subsequently, a genetic algorithm was applied to find optimal conditions for the neural network model, in an approach called neuro-genetic. A single laser induced breakdown spectroscopy working condition that maximizes peak areas of all elements simultaneously, was obtained with the following optimized parameters: 9.0 µs integration time gate, 1.1 µs delay time, 225 (a.u.) amplification gain and 30 accumulated laser pulses. The proposed approach is a useful and a suitable tool for the optimization process of such a complex analytical problem.

El objetivo de este estudio fue determinar la composición química del tejido vegetal en menta y su relación con la concentración de nutrientes en el suelo. Se evaluaron parámetros de crecimiento y la concentración de elementos de la parte aérea de la planta al momento de la cosecha, en 35 cultivos comerciales ubicados en el departamento de Cundinamarca (Colombia). Paralelamente se determinaron las propiedades químicas del suelo en que crecían las plantas. La concentración de macroelementos en el tejido vegetal mostró el siguiente orden (% de materia seca): K (1,07-7,23) gt; N (1,57-4,74) gt; Ca (0,66-1,36) gt; P (0,24-0,64) gt; Mg (0,14-0,60); para los microelementos (mg·kg-1) fue: Fe (89-596) gt; Mn (19-303) gt; Zn (47-134) gt; B (16-108) gt; Cu (8-13). No se encontraron relaciones significativas entre los nutrientes en el suelo y la planta que permitieran explicar las variables de crecimiento. Se presentaron correlaciones significativas entre Mg y P en el suelo y sus concentraciones en la planta (r=0,65** y 0,60*, respectivamente) y del Mg en el suelo y el Mn en la planta (r=-0,60*). La mejor correlación se presentó entre la relación K/Mg en el suelo y el Mg en el tejido vegetal (r=-0,73**), poniendo de manifiesto el antagonismo entre ambos nutrientes y la importancia del balance catiónico K-Mg en el suelo. En general se puede afirmar que los suelos cultivados con menta no presentaron limitaciones en la disponibilidad de nutrientes, muy probablemente por el manejo intensivo de la fertilización. The objective of this study was characterizing the chemical composition of plant tissue in mint and its relation to the mineral concentration in soil. The fresh weight, dry weight, height and number of knots, and the elemental concentration in aerial part of plants from 35 commercial crops at the time of harvesting were evaluated, as well as the soil chemical properties. The concentration of macronutrients in the plant tissue of mint showed the next order (% dm): K (1.07-7.23) gt; N (1.57-4.74) gt; Ca (0.66-1.36) gt; P (0.24-0.64) gt; Mg (0.14-0.60), and that one for the microelements (mg·kg-1): Fe (89-596), Mn (19-303), Zn (47-134), B (16-108), Cu (8-13). No significant relations between the nutrients in soil and plant that permit to explain, in some degree, the growth variables were found. We would find significant correlations between Mg and P in soil and their concentrations in plants (r=0,65** y 0,60* respectively) and between Mn in soil and its concentration in plant (r=-0,60*). The best correlation was found between the K/ Mg ratio in soil and Mg in plant tissue (r=-0,73**) making these clear the antagonism between both nutrients and importance of cation balance in soil. The concentration of nutrients in mint was similar to the one reported in the other crops. In general, we can say that soils cultivated with mint donacute;t show limitations in regards to nutrient availability, probably, due to the intensive management of fertilization.