Papers by Geraldo Deffune
Keywords: allelopathy, biodynamic, organic, quality, sustainability, silicon. To verify the effec... more Keywords: allelopathy, biodynamic, organic, quality, sustainability, silicon. To verify the effectiveness of an established set of agricultural techniques involving application of natural solutions and extracts, crop rotations and associations - here collectively designated as Applied Allelopathy; a sequence of field, glasshouse and laboratory experiments was carried out from 1993 to 1997. Two test crops of world importance - wheat and potatoes, were chosen to provide responses from both a Mono and a Dicotyledon with physiologically different growing habits and end products (grains, tubers). The following treatments were tested: 1. Field sprays - used in sequence and additional to compost treatments: P500 soil spray (fermented cow manure), P501 plant spray (ground quartz), Nettle aqueous extract (Urtica dioica - planta tota), Equisetum axvense decoction and Kieselguhr (diatomaceous earth) suspension. 2. Compost additives P502 to P507 (200 mg.m-3) : Achilea millefolium - flowers, Matricaria recutita - flowers, Urtica dioica-planta tota, Quercus robur - bark, Taraxacum officinale - flowers and Valeriana officinalis - flowers' liquid extract. 3. Rotations with a Rye-Vetch mixture for assessment on crop responses and weed suppression through green manuring and mulching. The specific objective is to identify whether and/or which of the biodynamic preparations, organic and mineral extracts and rotations with weed suppressing green manures, do have allelopathic effects on the yield and quality (e.g., baking and storage properties) of wheat and potatoes. A general objective is to develop and test an integrated set of simple methodological designs that can combine systems (holistic) and analytical approaches, built upon a coherent critical philosophical-scientific foundation. Although the main scope of this research work is on the Agronomic aspects and results, some indications of the underlying physiological and biochemical mechanisms involved in the obtained results are given. Consecutive series of randomised complete block design (split-plots and factorials) field and glasshouse trials were carried out as blind-coded experiments, comparing Control, NPK, Organic and Biodynamic compost soil treatments, combined with field sprays and extracts in different dilutions. Results were based on field assessment of growth, biomass, weeds and yields; storage and laboratory analysis of quality parameters such as thousand grain weight (wheat TGW), Hagberg Falling Number (wheat HFN), dry matter and mineral contents, storage losses, grading and tissue browning (potatoes). The method of Selected Orthogonal Contrasts for partitioning the treatment sums of squares was used to allow specific comparisons between treatments. Significant differences using the F-test, were found both for the interaction of soil treatments and sprays overall in the field experiments and for several comparisons involving individual treatments and dilutions. The BD and organic systems offered significant positive differences in relation to the nil control, in terms of both yields (for both wheat and potatoes) and quality. This was expressed especially in the lower potato storage tissue browning and its resulting higher net amount of good marketable tubers, but also in the ideal wheat baking quality achieved by the BD treatment. Organic and BD yield increases did affect quality parameters like wheat TGW and potato DM%, which remained as high as in the control. They also did not cause any significantly different increase in soil nitrate and ammonium, actually displaying the same levels of these compounds as the control in the soil analysis results.The agrochemical treatment (Nitram for wheat, NPK for potatoes) produced significantly higher yields only in the wheat trials, but offered significantly lower values of wheat TGW and potato DM%, and very significantly increased soil nitrate levels in the soil, even after harvest time. The BD and organic systems did not differ in general in terms of yields, although there were trials like potato'93 in which the organic yielded significantly less than the agrochemical treatment, while the BD did not. It was in terms of both wheat and potato quality that the BD treatment system showed the following significant advantages, even over the comparatively equivalent organic system: • Ideal wheat flour baking quality (HFN, well-balanced alpha-amylase activity). • Significantly less potato tuber pest field damage and storage losses by tissue browning. Biodynamic and allelopathic sprays, like silica P501 and nettle water (Urtica dioica), can significantly improve yields and quality of both potatoes and wheat. However, their general mode of action can be defined as regulatory or "normalising", considering that when over-applied at near optimum crop conditions, they can reduce yields and negatively affect quality parameters. A green manure rotation and mulch like the rye plus vetch mix used in Experiments Three and Four (1994)…
Alelopatía en los sistemas biológicos y biodinámicos: investigación sobre la calidad y la productividad del trigo y la patata, 1994
Experimentos de campo del PhD en Wye College - Universidad de Londres, evidenciaron efectos alelo... more Experimentos de campo del PhD en Wye College - Universidad de Londres, evidenciaron efectos alelopátícos significativos de los sistemas de tratamientos orgánicos (o biológicos) y biodinámicos en la calidad y la productividad de trigo y patata.
Efectos de los ácidos húmicos y de tres preparados biodinámicos en el crecimiento de plántulas de trigo, 1994
Experimentos axénicos en soluciones nutritivas completas evidenciaran los efectos de los ácidos h... more Experimentos axénicos en soluciones nutritivas completas evidenciaran los efectos de los ácidos húmicos y de tres preparados biodinámicos en el crecimiento de plántulas de trigo.
Artigo histórico sobre os *0 anos do Curso Agrícola de Rudolf Steiner que originou a Agricultura ... more Artigo histórico sobre os *0 anos do Curso Agrícola de Rudolf Steiner que originou a Agricultura Biodinâmica e o Conceito de Organismo ou Individualidade Agrícola que inspirou a criação da denominação Agricultura Orgânica.
Projet de Recherche en Agroecologie Appliquée Université ParisVII, Mai, 1987.
Allelopathic effects are biochemical interactions of both inhibitory and stimulatory nature betwe... more Allelopathic effects are biochemical interactions of both inhibitory and stimulatory nature between plants and microorganisms. Both opposites seem to be separated by quite a thin line-most organic compounds that are inhibitors at some concentrations are stimulators to the same processes at higher dilutions (Rice 1984). The mode of action of plant growth hormones such as indole-3yl-acetic acid (IAA) illustrates this phenomenon: while 10-11 M is the optimum level for roots, concentrations above 10-6 M strongly inhibit root growth (Audus 1972). In this context humus and humic acids (HA) have also been the subject of several studies related to plant growth. Bio-dynamic farming is the oldest movement for sustainable agriculture. It differs from the other movements basically by the use of the bio-dynamic (BD) preparations: mineral, plant or animal extracts, usually fermented and applied in small proportions to organic manures, the soil or directly on plants, after dilution or stirring procedures called dynamizations. Methods: Two randomised complete block experiments were carried out using axenic culture of wheat seedlings using Murashige and Skoog salts (final concentration of 1.15 g l-1 in deionized water): experiment 1-with factorial treatment structure plus added control to test three different dilutions (table 1) of BD preps and three HAs as well as a positive control using IAA; experiment 2-the same treatments only at the lowest dilution with two concentrations of IAA, without using rhythmic stirring.
Relatório de Bolsista de Doutorado no Exterior - CNPq, Brasília - DF, Brasil., Jan 20, 2000
Resumo de pesquisa de Doutoramento que verificou a vantagens significativas de sistemas tratament... more Resumo de pesquisa de Doutoramento que verificou a vantagens significativas de sistemas tratamentos Biológico-Dinâmicos e Orgânicos comparados aos controles positivos com agroquímicos e testemunhas absolutas na produtividade e qualidade de Trigo e Batatas, numa sequência de oito experimentos de campo, dois de estufa ou casa de vegetação e várias análises de laboratório realizados entre Março de 1993 e Setembro de 1997, no Wye College, Universidade de Londres.
A PhD research project was carried forward between 1993 and 1998 to investigate biodynamic and or... more A PhD research project was carried forward between 1993 and 1998 to investigate biodynamic and organic treatment systems effects on wheat and potato crop rotations. Significant differences in crop yield and health, nutritional and keeping qualities of produce as well as soil nitrogen content were found, favouring the biodynamic and organic treatment systems.
Thesis Chapters by Geraldo Deffune
Effects of Humic Acids and three Bio-dynamic Preparations on the growth of wheat seedlings., 1990
Considering the effective presence of both IAA and humic acids in organic matter in general and t... more Considering the effective presence of both IAA and humic acids in organic matter in general and the results obtained in other research works showing active stimulation of plant growth by the so called bio-dynamic preparations, two sets of experiments were carried out using axenic culture of wheat seedlings, one a factorial experiment plus added control to test three different dilutions of three BD preparations and three different humic acids as well as a positive control using IAA, the other a randomized block design to test the same treatments only in the lowest dilution with two concentrations of IAA, without using rhythmic stirring for the dilutions.
The results suggest that both BD preparations and humic acids do have an effect similar to the ones by auxins in general, but differential in relation the different dilutions, stimulation in terms of dry weight and height increases being obtained even with dilutions as high as 10-25, including the treatment with IAA.
Four different measurements were made that seemed to confirm each other: root length, shoot height, fresh and dry weights.
The method of Selected Orthogonal Contrasts for partitioning the treatment sums of squares was used to allow specific comparisons between treatments, significant differences being found both for the interaction of treatments versus dilutions overall in the factorial experiment and for several specific comparisons involving individual treatments and some combinations, at the 5% level for the F-test.
In the second, smaller set of experiments, no significant differences were detected, except for the comparison between humic acids.
We concluded that humic acids are effective mostly at lower dilutions of the order of 10-3, that the BD preparations are more effective at their usual field dilutions and that there is a yet unexplained mechanism for the high activity found in the highest dilutions of both IAA and P 505, confirming the conclusions of previous researchers in general.
Allelopathic influences of organic and bio-dynamic treatments on yield and quality of wheat and potatoes, 2000
Many organic substances have allelopathic effects in agroecosystems (Rice, 1984). The so-called b... more Many organic substances have allelopathic effects in agroecosystems (Rice, 1984). The so-called biodynamic (BD) preparations were the first set of plant extracts and solutions widely used in what can be regarded as applied allelopathy in farming systems (Deffune, 1990). This method has been successfully used by Brazilian farmers (Pio et al, 1984) and holds great potential regarding biodiversity, for the discovery of new sources of active principles or ingredients (Almeida, 1988). A PhD research project was carried forward between 1993 and 1998 to investigate these effects and techniques.
Spring wheat (T. aestivum, var. Canon) and potatoes (S. tuberosum, vars. Cara and Pentland Crown), two of the world’s most important staple foods, were chosen as test crops in field trials also for being complementary in a polar sense – one a Old World Monocotyledon ear producer; the other a New World Dicotyledon tuber producer.
A mixed green manure rotation with rye (Secale cereale) plus vetch (Vicia sativa) was added to the field trials to simulate an organic farming system. Field trials were supplemented by laboratory and glasshouse experiments.
Crop yield and health, nutritional and keeping qualities of produce as well as soil nitrogen content levels were the parameters evaluated, showing significantly positive differences in yields and quality for the Biodynamic system.
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Papers by Geraldo Deffune
Thesis Chapters by Geraldo Deffune
The results suggest that both BD preparations and humic acids do have an effect similar to the ones by auxins in general, but differential in relation the different dilutions, stimulation in terms of dry weight and height increases being obtained even with dilutions as high as 10-25, including the treatment with IAA.
Four different measurements were made that seemed to confirm each other: root length, shoot height, fresh and dry weights.
The method of Selected Orthogonal Contrasts for partitioning the treatment sums of squares was used to allow specific comparisons between treatments, significant differences being found both for the interaction of treatments versus dilutions overall in the factorial experiment and for several specific comparisons involving individual treatments and some combinations, at the 5% level for the F-test.
In the second, smaller set of experiments, no significant differences were detected, except for the comparison between humic acids.
We concluded that humic acids are effective mostly at lower dilutions of the order of 10-3, that the BD preparations are more effective at their usual field dilutions and that there is a yet unexplained mechanism for the high activity found in the highest dilutions of both IAA and P 505, confirming the conclusions of previous researchers in general.
Spring wheat (T. aestivum, var. Canon) and potatoes (S. tuberosum, vars. Cara and Pentland Crown), two of the world’s most important staple foods, were chosen as test crops in field trials also for being complementary in a polar sense – one a Old World Monocotyledon ear producer; the other a New World Dicotyledon tuber producer.
A mixed green manure rotation with rye (Secale cereale) plus vetch (Vicia sativa) was added to the field trials to simulate an organic farming system. Field trials were supplemented by laboratory and glasshouse experiments.
Crop yield and health, nutritional and keeping qualities of produce as well as soil nitrogen content levels were the parameters evaluated, showing significantly positive differences in yields and quality for the Biodynamic system.
The results suggest that both BD preparations and humic acids do have an effect similar to the ones by auxins in general, but differential in relation the different dilutions, stimulation in terms of dry weight and height increases being obtained even with dilutions as high as 10-25, including the treatment with IAA.
Four different measurements were made that seemed to confirm each other: root length, shoot height, fresh and dry weights.
The method of Selected Orthogonal Contrasts for partitioning the treatment sums of squares was used to allow specific comparisons between treatments, significant differences being found both for the interaction of treatments versus dilutions overall in the factorial experiment and for several specific comparisons involving individual treatments and some combinations, at the 5% level for the F-test.
In the second, smaller set of experiments, no significant differences were detected, except for the comparison between humic acids.
We concluded that humic acids are effective mostly at lower dilutions of the order of 10-3, that the BD preparations are more effective at their usual field dilutions and that there is a yet unexplained mechanism for the high activity found in the highest dilutions of both IAA and P 505, confirming the conclusions of previous researchers in general.
Spring wheat (T. aestivum, var. Canon) and potatoes (S. tuberosum, vars. Cara and Pentland Crown), two of the world’s most important staple foods, were chosen as test crops in field trials also for being complementary in a polar sense – one a Old World Monocotyledon ear producer; the other a New World Dicotyledon tuber producer.
A mixed green manure rotation with rye (Secale cereale) plus vetch (Vicia sativa) was added to the field trials to simulate an organic farming system. Field trials were supplemented by laboratory and glasshouse experiments.
Crop yield and health, nutritional and keeping qualities of produce as well as soil nitrogen content levels were the parameters evaluated, showing significantly positive differences in yields and quality for the Biodynamic system.