May 2005 No. 2


Results and updates

First Delphi Expert Survey on organic food processing

Report on organic rodent control strategies

QLIF Congress 2005

Health in focus

Consumer issues

Product quality and health

Crop production system

Livestock production system

Processing strategies

Related projects

Organic HACCP

Blight MOP

QLIF Notes

Congress in DK 2006

PhD summer school

PhD seminar on soil quality



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Crop Production System

Soil quality

The Albrecht® Soil Survey

Phosphorous deficiencies on Canadian organic farms

Is conventional soil analysis of any use for organic systems?

Seed protection

Seed treatment in organic agriculture

Biocontrol of soil borne diseases - environmental effects

Soil fertility management

Wheat varieties and mixtures for organic agriculture

Horse powered traction and tillage

Long-term impact of stockless organic conversion strategies

Field vegetables
Green manure, catch crops, and deep rooted crops in organic vegetable crop rotation

Fertility management and economics in organic field vegetable rotations

Length of fertility building phase - impact on nitrogen balances

Improving crop health management

NE organic winter wheat variety trial

Beneficial and pest invertebrate species in a stockless organic farming system

Field vegetables
Organic vegetable module propagation

Integrated crop and pest management - horticultural crops in Poland

The use of bioinoculants and biostimulants to reduce nutrient and pesticide requirements

Quality and yield of organic apples due to soil and fertility management

Organic apple production - varieties and integrated pest and disease management in the UK

Glasshouse crops
Integrated control of soilborne and foliar pathogens in organic greenhouse crops

A practical approach to pest management in organic glasshouse tomatoes

Soil quality

The Albrecht® Soil Survey

Ian Robertson, Glenside Organics Ltd

Conventional soil tests provide insufficient information from which to be able to maximise the natural productivity of many soils.

The Albrecht® Soil Survey is a powerful and practical diagnostic aid to understanding the intricate inter-dependence of the three key parameters of soil – the chemical, the physical and the biological.

The objective is to improve profitability by identifying and correcting imbalances in the soil which are:

1. Adding unnecessarily to the costs of production

2. Adversely affecting the marketability of crops

3. Inhibiting the health and performance of livestock

Soil is an indivisible team of three – chemical, physical, biological with each one potentially affecting the efficient working of the other. The chemical affects the physical which in turn affects soil biology. The Albrecht Soil Survey reveals imbalances in the soil which make the rooting environment less hospitable for root development thereby inhibiting the plant’s ability to access a balanced range of nutrients. Imbalanced soils and poor microbial activity restrict the soil’s ability to contribute to optimum yields and quality. Imbalanced soils impact adversely on margins.

The Glenside Albrecht® Soil Survey reports on:

Soil Characteristics
Cation exchange capacity, Colloidal organic matter, Soil type.

Trace elements
Boron, Iron, Manganese, Copper, Zinc, Molybdenum.

Base saturation percentages
Calcium, Magnesium, Potassium, Sodium, Hydrogen & "others".

Acidity/Alkalinity - pH

Cation Surpluses/Deficits
Desired and found values in kg/ha for the cations, Calcium, Magnesium, Potassium.

Values for:
Sodium, Sulphate and Estimated Nitrogen Release (ENR) Phosphate values in terms of found and desired in kg/ha. “Totals” – combined total of available and currently unavailable but exploitable soil reserves of Calcium, Magnesium, Phosphorus, Sulphur, Potassium and Sodium.

TECHNICAL SEMINAR 25: Effective soil analysis in organic systems, Talk 1

Phosphorous Deficiencies on Canadian Organic Farms

Ralph C. Martin et al., Organic Agriculture Centre of Canada

Many Canadian organic farms are deficient in available soil phosphorous (P). Knight and Shirtliffe (2003) surveyed 84 organically managed fields in Saskatchewan and found all were deficient in available soil P. Entz et al (2001) surveyed organic farms in the eastern Prairies and found consistent deficiencies in available P. Lynch et al. (2004) tested 227 soils on organic farms in Ontario and the majority were low to very low in available P.

Organic producers have few viable alternatives for P management. Rock phosphates can be acceptable to organic standards (provided they are low in heavy metals, and not processed synthetically), but the P in these becomes available slowly, especially in high pH soils. Other options involve trying to increase availability biologically. Enhanced microbial activity in organically managed soils may make P more available (Mader et al 2002). Some agronomic practices including use of green manures, can increase microbial activity, and may make P more available.

Livestock manures are rich sources of available phosphorus, but a majority of organic farmers do not keep livestock, or have too few livestock to adequately fertilize their cropland. Off-farm manure sources are subject to organic regulations and hauling costs, both of which may be prohibitive. Furthermore, manure from conventional farms in Canada may be contaminated by genetically modified material from corn and soybean feed.

Entz, M., Gulford, R., and Gulden, R. 2001. Crop yield and soil nutrient status on 14 organic farms in the eastern portion of the northern Great Plains. Can. J. Plant Sci. 81: 351-354.

Knight, J.D. and Shirtliffe, S. 2003. Saskatchewan Organic On-Farm Research: Part I: Farm Survey and Establishment of On-Farm Research Infrastructure. Project 20010016. Final Report: March 15, 2003.

Lynch, D.H.., Voroney, R.P., Fredeen, A.H. and Martin, R.C. 2004. Integrated Nutrient Management for Organic Dairying in Ontario. Annual Project Report, 2003-2004. Prepared for the Ontario Ministry of Agriculture and Food.

Mader, P., Fliesbach, A., Dubios, D., Gunst, L., Fried, P., and Niggli, U. 2002. Soil fertility and biodiversity in organic farming. Science 296:1694-1697.

TECHNICAL SEMINAR 25: Effective soil analysis in organic systems , Talk 2

Is conventional soil analysis of any use for organic systems?

Elizabeth Stockdale & Christine Watson, University of Newcastle upon Tyne & Scottish Agricultural College, UK

Watson et al (2002) clearly showed that nutrient management in organically managed soils is fundamentally different to the practices applied to soils managed conventionally. However, Stockdale et al (2002) concluded that the same nutrient cycling processes operate in organically and conventionally farmed soils and that nutrient pools in organically farmed soils are also essentially the same as in conventionally managed soils. However, the focus in the organic system on the use of organic materials and the restriction on the use of soluble fertilizers may lead to an increased proportion of nutrients held in organic forms (N, P, S), associated with the charged surfaces of SOM (K, and other cations) or remaining in undissolved rock fertilizers (P). While the total pool of any nutrient may not be different between conventionally and organically managed farming systems, its composition may be (Stockdale et al, 2002).

Most routine soil analysis has been developed for application in conventional systems. Even ‘new’ approaches to soil analysis often only determine the availability of nutrient pools in soil using simple chemical extraction methods. In this presentation we will consider the strengths and weaknesses of conventional soil analyses for organic farming systems, and seek to stimulate discussion on what the most appropriate sampling and analysis protocols for organic farming systems might be.

Watson CA, Atkinson D, Gosling P, Jackson LR & Rayns FW 2002. Managing soil fertility in organic farming systems. Soil Use and Management 18, 239-247.

Stockdale EA, Shepherd MA, Fortune S & Cuttle S 2002. Soil fertility in organic systems – fundamentally different? Soil Use and Management 18, 301-308.

TECHNICAL SEMINAR 25: Effective soil analysis in organic systems , Talk 3

Seed protection

Development and presentation of strategies for seed treatment in organic agriculture

Werner Vogt-Kaute et al., Naturland e.V., Germany

Although seed borne disease often cause problems for organic farmers, appropriate seed treatments are not available for certain disease/crop plant combinations. Within the framework of the German Federal Organic Farming Scheme (“Bundesprogramm Ökologischer Landbau”) several researchers and representatives of organic sector bodies started to work on evaluating and improving methods for seed treatments that are acceptable in organic agriculture. Both the evaluation of efficacy of treatments and the suitability of treatments for use on farm were important criteria in the evaluation.

The paper will present results from partner institutions based on

(i) several years of trials evaluating seed treatments for common bunt of wheat (Tillietia caries), loose smut of wheat and barley (Ustilago tritici and Ustilago nuda), ascochyta blight of peas and

(ii) results on resistance of cereal varieties against common bunt of wheat (Tilletia caries), loose smut of winter barley (Ustilago nuda) and covered smut of winter barley (Ustilago hordei).

Results show that Tillecur (a mustard extract) can provide control against common bunt spores of which are on the seed surface. Electronic treatment are also active against inocula on the seed surface, but it is not clear whether this method will be approved under organic farming standards. Warm and hot water treatment showed some control on fungal pathogens which infect internal areas of the seed and are therefore more difficult to treat. Both the temperature and duration of such treatment need to be optimised to avoid negative impacts on seed germination rates.

Results from an (a) and initial field trials into the control of other diseases, e.g. loose smut and leaf stripe (Drechsera graminea) of spring barley and antracnose of lupins, (b) laboratory assays and soil based “cold test” carried out to evaluate the activity of treatments against Fusarium and Septoria and (c) part of the project that are concerned with seed borne diseases of vegetables, spices and herbs will also be reported.

Vogt-Kaute, W and Tilcher, R (2004) Control of common bunt of wheat (Tilletia caries) by alternative seed treatment, In: Proceedings of the First World Conference on Organic Seed, (pp. 124 – 126), FAO/IFOAM/ISF, Rome.

Tilcher, R. and Vogt-Kaute, W. (2004) The effect of seed treatment for the control of bird damage in corn and ascochyta blight of pea. In Proceedings of the First World Conference on Organic Seed, (p. 138 – 141) FAO/IFOAM/ISF, Rome.

Jahn M., Kromphardt C., Forsberg G., Werner S., Wikström M., Groot S. and Rop N (2004) Control of seed-borne pathogens on vegetables by physical seed treatment methods, in: Proceedings of the First World Conference on Organic Seed, (p. 177) FAO/IFOAM/ISF, Rome.

Spiess H. (2003) Stand der Weizensteinsteinbrandbekämpfung im Ökologischen Landbau, in: Wissenschaftstagung zum Ökologischen Landbau, (p. 565 – 566), Vienna.

TECHNICAL SEMINAR 20: Seed production and protection, Talk 1

Effect of environmental conditions on the biocontrol of soil borne diseases

Christoph Schmidt et al., Nafferton Ecological Farming Group, University of Newcastle, UK

Soilborne diseases can cause large yields losses due to incomplete emergence. Biocontrol agents, (i.e. bacteria and fungi, which inhibit plant pathogenic fungi) may be a valuable tool in organic agriculture, where synthetic fungicides are not permissible. However, the variability in disease control performance of biocontrol agents under field conditions is still higher compared to chemical pesticides. This is probably due to the variation of environmental parameters, which influence survival and performance of biocontrol agents. Biocontrol bacteria (Pseudomonas sp. and Bacillus subtilis) provided a high and reliable degree of disease control in high humidity fogging glasshouses where environmental conditions are highly controlled (1); their effect was less consistent in repeated glasshouse trials under variable conditions. (2). The EU project EU-FAIR Improbioseed tried to identify environmental conditions required by the biocontrol agents Pseudomonas fluorescens and Bacillus subtilis. In particular, the effect of the soil parameters pH, soil type, soil temperature and moisture (matrix potential) on microbial colonisation of roots and biocontrol activity against Pythium damping-off of sugar beet was investigated. Whereas the antagonistic bacteria Pseudomonas fluorescens and Bacillus subtilis colonised roots under all tested conditions, soil type, soil moisture and temperature, but not soil pH had a significant effect on biocontrol of Pythium damping-off disease. Biocontrol of Pseudomonas fluorescens was positively correlated with fine silt and organic carbon content of the soils; furthermore it was more pronounced under temperature and moisture conditions sub-optimal for the fungus. These results are reviewed in the context of previously published papers (1, 2).

Berger F, Hong Li, White D, Fraser R and Leifert C 1996 Effect of pathogen inoculum, antagonist density and plant species on biological control of Phytophtora and Pythium damping-off in high-humidity fogging glasshouses. Phytopathology 86, 428-433.

Georgakopoulos, D.G., Fiddaman, P., Leifert, C., and Malathracis, N.E. 2002. Biological control of cucumber and sugar beet damping-off caused by Pythium ultimum with bacterial and fungal antagonists. J. Appl. Microbiol. 92: 1078-1086.

Schmidt, C.S., Agostini, F., Leifert, C., Killham, K., and C.E. Mullins (2004) Influence of soil temperature and matric potential on sugarbeet seedling colonization and suppression of Pythium damping off by the antagonistic bacteria Pseudomonas fluorescens and Bacillus subtilis. Phytopathology 94, 351-363

Schmidt, C.S., Agostini, F., Simon, A., Whyte, J., Leifert, C., Killham, K., and C.E. Mullins (2004) Influence of soil type and soil pH on sugarbeet seedling colonization and suppression of Pythium damping off by antagonistic bacteria. European Journal of Plant Pathology 110, 1025-1046

TECHNICAL SEMINAR 20: Seed production and protection , Talk 2

Related to QLIF WP 3.2

Soil fertility management

Wheat Varieties and Mixtures for Organic Agriculture – Appropriate Science and Decisions

S. L. Phillips, Elm Farm Research Centre, UK

Elm Farm Research Centre (EFRC) has been running organic trials with wheat varieties over a number of years and sites. High levels of variability exist both within sites and between sites that mean that deriving robust answers to variety choice questions are difficult and unsafe. For this reason and others, variety choice for organic growers is much more a function of the biological interactions within the production system than it is for conventional producers. EFRC therefore recognises the value of linking together small scale plot trials over a few sites with larger scale strip trials across many sites in understanding the potential performance and stability of performance of different varieties in organic systems.

Data from five years of trials on UK organic farms will be presented to explore these observations and concepts.

TECHNICAL SEMINAR 16: Agronomy and fertility management – Arable crops, Talk 1

Horse Powered Traction and Tillage - Some Options and Costs for Sustainable Agriculture. With applications for both western and developing nations

Chet Kendell, Michigan State University

Often overlooked, the use of the heavy horse for agricultural traction and tillage persists in the Unites States. Research at Michigan State University indicates a major increase in Michigan of the use of equines as work animals. Amish and many others are effectively using horses for traction and tillage. Ever increasing numbers of environmentally conscious organic and sustainable farmers can often be found at trade conferences quietly discussing the practicality of using horses. Horses reduce the off-farm inputs of diesel fuel and lubricants and the pollution caused by internal combustion and petrochemical disposal. At the same time horses fit well into a diverse farming system already embracing livestock as they minimize ground compaction and their manure contributes to soil fertility and health. Using horses in agriculture can facilitate positive community interaction.

This paper takes a look at the issue from a praxis perspective, as a practicing sustainable farmer who uses draft horses extensively on his own farm and as a Ph.D. student completing his degree. It provides a model for the individual farmer to evaluate their potential costs and benefits of using horses for traction and tillage. Fundamental economics and values are discussed. This analysis is expanded to include variability in labor and fuel rates with implications for international agriculture. The analysis indicates that even though the choice to use horses is often a value laden moral choice, there is also an economic basis for doing so, especially if the regenerative potential of the horses is utilized. This conclusion is dependent on the scale of farming operations with the price of labor and fuel being other key variables.

Lal, R., 1999, Long term traffic and wheel traffic effects. Journal of Sustainable Agriculture. Vol. 14, 67-84.

McQuail, Tony, 1993, Farming with Work Horses, Ecological Farmers Association of Ontario.

Miller, Lynn R. 1981, Work Horse Handbook, Small Farmers Journal Inc.

Shelle, John and Gallagher, Ken, 1998, The Michigan Horse Industry Overview, Michigan State University Extension, Special Reports – SR489201

TECHNICAL SEMINAR 16: Agronomy and fertility management – Arable crops, Talk 2

The long-term impact of stockless organic conversion strategies

Alison Rollett et al., University of Nottingham, UK

The effects of seven conversion strategies on subsequent organic crops were investigated on a sandy loam and a clay loam soil. The strategies were: 1. two-years’ red clover-ryegrass green manure, 2. two-years’ hairy vetch green manure, 3. red clover for seed production then a red clover-ryegrass green manure, 4. spring wheat undersown with red clover, then a red clover green manure, 5. spring wheat, then winter beans, 6. spring oats, then winter beans, 7. spring wheat undersown with red clover, then a barley-pea intercrop. Post conversion the first organic crop was winter wheat (2001-2), followed by winter beans in 2002-3 and winter oats in 2003-4. Conversion strategies had a significant impact on organic wheat yield, which ranged from 2.8 to 5.3 t ha –1. Establishment was the main determinant of wheat yield, and 89% of the variation in establishment could be explained by differences in soil structure and texture. Organic wheat yield was not related to weed abundance or soil mineral nitrogen. In contrast, weed abundance was an important factor in determining organic bean yield. Together with plant establishment it accounted for 54% of yield variation. Both wheat and beans had poor levels of establishment with fewer than 50% of plants establishing. Conversely, winter oats had establishment levels of over 90% in all conversion strategies and hence this was not important in explaining yield differences. Significant differences in soil mineral nitrogen between conversion strategies were still evident when the oat crop was grown. These differences, along with weed numbers prior to harvest and soil texture, accounted for 49% of variation in yield. Yield was generally greatest in the organic cereal crops following the three red clover based strategies (1, 3 and 4). However, yields from the bean crop were more variable, perhaps reflecting the crop’s non-dependence on soil mineral nitrogen. The choice of conversion strategy has been shown to affect yield of crops grown up to three years post conversion. Overall, the clover based strategies led to greater yields in the subsequent rotation through their effects on soil structure, soil mineral nitrogen and, to a lesser extent, weed burden.

Bulson, H.A., Welsh, J.P., Stopes, C.E. AND Woodward, L. (1996) Agronomic viability and potential economic performance of three organic four year rotations without livestock, 1988-1995. Aspects of Applied Biology 47, 277-286.

Huxham, S.K., Wilson, P. and Sparkes, D.L. (2004a). Economic Analysis of Conversion Strategies for Stockless Organic Production. Biological Agriculture and Horticulture, 22 (3), 289-303.

Huxham, S.K., Sparkes, D.L. and Wilson, P. (2004b). The Effect of Conversion Strategy on the Yield of the First Organic Crop, Agriculture, Ecosystems & Environment (in press).

TECHNICAL SEMINAR 16: Agronomy and fertility management – Arable crops, Talk 3

Use of green manure, catch crops, and deep rooted crops for nutrient management in an organic vegetable crop rotation

Kristian Thorup-Kristensen

Green manure crops are important in organic rotations to improve soil quality and to deliver nutrients for the cash crops. Many of the effects of green manure contribute to long term improvement of soil quality. This is also true for their effect on nitrogen supply, but they typically have a large effect in the first year, followed by quite small effects in the succeeding years (Thorup-Kristensen et al, 2003). New strategies for including green manure and cover crop in the rotations may be needed, to avoid excessive nitrogen release from green manure compared to cash crop demand, and to secure good nitrogen supply not only for one crop following a full year green manure, but for more of the crops in a rotation.

Results from a crop rotation experiment (Thorup-Kristensen, 1999) have shown the potential of strategies with more frequent use of short term green manure crops and catch crops. Green manures grown only in the autumn after cash crop harvest can release much nitrogen for the succeeding crops, and reduce nitrogen leaching losses. In any crop rotation, and especially in vegetable rotations, some nitrogen will inevitably be lost by leaching. In order to reduce these losses, deep rooted catch crops or cash crops can be used strategically in the crop rotation, to retain nitrogen in the soil, or to take up nitrogen which has already leached to larger soil depths (Thorup-Kristensen, 2001; 2002). Results from the rotation, show that some crops or cover crops with deep root systems are able to assimilate nitrogen from more than 2 meters soil depth, and that this can be a powerful tool in reducing nitrogen losses from the crop rotation.

Thorup-Kristensen, K., Magid, J. and Jensen, L.S. 2003 Catch crops and green manures as biological tools in nitrogen management in temperate zones. Advances in Agronomy, 79: 227-301

Thorup-Kristensen, K. (2002) Utilising differences in rooting depth to design vegetable crop rotations with high nitrogen use efficiency (NUE). Acta Horticulturae 571: 249-254

Thorup-Kristensen, K. (2001) Are differences in root growth of nitrogen catch crops important for their ability to reduce soil nitrate-N content, and how can this be measured? Plant and Soil, 230: 185-195

Thorup-Kristensen, K. (1999) An organic vegetable crop rotation aimed at self-sufficiency in nitrogen. In: Olesen, J.E., Eltun, R., Gooding, M.J., Jensen, E.S. & Köpke, U. (Eds) Designing and testing crop rotations for organic farming. DARCOF Report no. 1. p 133-140

TECHNICAL SEMINAR 17: Agronomy and fertility management – Field vegetables, Talk 1

Balancing fertility management and economics in organic field vegetable rotations.

C. Firth et al., HDRA, Ryton Organic Gardens, UK

Organic field scale vegetables have the potential to earn high returns per hectare. They are one of the most profitable enterprises in organic arable farming systems, with physical inputs being relatively low, however, labour and managerial inputs are high and so are the risks. Vegetables are also some of the most nutrient demanding crops grown. Many organic arable systems with field-scale vegetables are stockless, therefore in the absence of animal manure the sustainability of the cropping sequences depends on nitrogen from fertility building crops. Fertility building crops are also important to the organic rotation in terms of soil management, weed, pest and disease control. However, economically these periods generate only costs and no income. Other crops like cereals and pulses are used to balance the rotations, but are also less profitable.

This paper will examine different strategies of fertility building and rotational design using results from two organic research sites in the UK and with comparisons from several UK commercial organic farms, monitored as part of a DEFRA funded project. On the research sites all outputs and inputs in terms of nutrients and money have been measured over a 6 year period, for example variable costs for key inputs as fertility building, weed control and pest and disease management. The rotational nutrient budgets will be assessed against the economics of the various rotations. The paper will discuss the implications for rotational planning to find a balance between high quality crops and low inputs.

Rayns, F. Harlock, S. and B. Turner (2002): Fertility building strategies during the conversion period – assessment of performance in a stockless field vegetable rotation. In: UK Organic Research 2002, Ed. J. Powell, 125-128

Schmutz, U., C. Firth, F. Rayns and C. Rahn (2004): Can N Use and Farm Income be Optimized for Organic Field Vegetable Rotations in Europe? In: Organic Farming Ed. A. Hopkins BGS Symposium No. 37. ISBN 0905944 844. p. 200-203

TECHNICAL SEMINAR 17: Agronomy and fertility management – Field vegetables, Talk 2

Length of fertility building phase - impact on nitrogen balances

C. A. Watson et al., Land Economy Department, SAC Edinburgh, UK

To ensure both short-term productivity and long-term sustainability of production on organic farms, it is crucial that a balance between inputs and outputs of nutrients is achieved. Organic systems are dependent on a fertility-building phase that precedes the exploitative arable-cropping phase. The fertility building phase, and hence the N accumulation is as a consequence of biological fixation. There is however much uncertainty regarding the rate of this N accumulation, and the length of time required for the grass clover ley to accumulate sufficient N to allow the growth of subsequent crops within the rotation. To explore the impact of the length of the fertility building phase on N balances, an experiment has been conducted over 12 years in the northeast of Scotland based on a six-course rotation with either a three or a four-year ley phase. A plot-by-plot systems N budget (Watson and Atkinson, 1999) has been calculated for each of the rotations over the period of the trial. The results indicate that although the accumulation of N in the soil and the losses from the system from the three-year ley are lower than from a four-year ley phase, the N accumulation is not proportional to the length of the time over which the ley had been grown. Nevertheless, the ratio of total outputs to total inputs tends to be higher for a rotation with three years of fertility building to three years of exploitation.

Watson, C. A. and Atkinson, D. (1999) Using nitrogen budgets to indicate nitrogen use efficiency and losses from whole farm systems: a comparison of three methodological approaches. Nutrient Cycling in Agrocecosytems 53, 259-267.

TECHNICAL SEMINAR 17: Agronomy and fertility management – Field vegetables, Talk 3

Improving crop health management

NE Organic Winter Wheat Variety Trial. 2004 Results

Andrew Wilkinson, Gilchesters Organics, UK

In the absence of any specific data or research work supporting organic wheat production in the NE region of England, the organic wheat producers lacked certain agronomic information such as variety choices, soil fertility regimes and disease patterns within the rotation with which to formulate a sound business structure. A wheat research programme for the NE was therefore established in 2003. The main areas identified for research were wheat protein content for milling quality and disease resistance, particularly fusarium susceptibility.

In 2003 a two year soil fertility trial was established on a 24.5 ha (60 acre) site in a stockless regime using red clover (trifolium pratense) with rhizobia innoculum and green waste compost treatments with the aim of growing milling quality wheat in the year following. In order to build up data on variety performances prior to the cultivar selection for the third year of the trial two years of spring and winter wheat trials were established in 2003 and 2004.

The choice of variety in wheat production has been sited as an important management tool in organic cereal production (Younie, Taylor, Welsh and Wilkinson 2002) as well as producing differences in grain yield and quality when attempting to achieve milling grades. The choice of a cultivar for straw length as a means of weed control has been questioned (Eisele and Köpke, 1997) and the much favoured Maris Widgeon was shown by Cosser et al (1997) as not being the best variety for suppressing weeds, despite it’s height.

The Winter wheat trial for 2004 examined 8 varieties under 3 fertility management systems with 4 replications. 6 varieties from the Swiss Organic Plant breeders “Sativa” were compared with 2 conventional UK milling varieties (Hereward and Malacca) available for organic production. The fertility treatments were 1 year of red clover (trifolium pratense) or 1 year grass ley +/- FYM.

The trial examined the effects of these treatments on varieties with differing agronomic traits and the relationship between these varieties and soil fertility management on crop establishment, weed suppression, disease resistance, lodging, yield and grain quality. The over-riding result was the effectiveness of clover in significantly benefiting crop production in all levels of agronomy. The combination of clover with the long straw varieties also produced significant differences in weed suppression. All of the organic “Sativa” varieties were significantly different to the conventional UK varieties in many aspects of the agronomic data analysed. The heavy and prolonged precipitation during June and at Harvest in August produced conditions regarded generally as unfavourable for conventional commercial wheat production in the NE but produced conditions exceptional for the examination of disease resistance, lodging and grain quality in winter wheat under organic production.

Cosser N D, Gooding M T, Davies W P, Thompson A J & Froud-Williams R J (1997). Cultivar and Rht gene influences on the competitive ability, yield, bread-making qualities of organically grown winter wheat. Aspects of Applied Biology 50, Opimising cereal inputs: Its scientific basis. 39-52

Eisele J A & Kopke U. (1997). Choice of Variety in Organic Farming: New criteria for winter wheat ideotypes. Pflanzenbauwissen-schaften, 1(1),5. 19-24

TECHNICAL SEMINAR 21: Improving crop health management – Arable, Talk 1

Related to QLIF WP 3.5

Case study: Beneficial and pest invertebrate species in a stockless organic farming system

J. Burke & P. Mycock, Organic Studies Centre, Duchy College, UK

It is acknowledged that organic production offers real benefits to the environment (DEFRA 2002) and contributes to improved biodiversity and balance of species numbers and population sizes on farmland (Soil Association 2000). Coswinsawsin Organic Demonstration Farm achieved full organic status in January 2001 and since then has been managed as a stockless rotation including cereals, cabbage and cauliflower, potatoes, lupins, sugar beet and fertility building legumes. In order to document invertebrate species present on the farm, a survey was conducted during a four week period from16th August to 9th September 2004. Collection methods included pitfall trapping and sweep netting. Two lines of pitfall traps were set. The first line comprised of 15 traps, set 2 metres apart and extended from a field corner diagonally into a field of winter wheat. The second line comprised of 20 traps, set 3 metres apart and extended at a right angle from the centre point of a hedgerow towards the centre of a field of lupins. The traps were checked daily. Sweep netting was carried out on a regular basis when weather conditions allowed, along three established field margins. Species collected by both trapping methods were removed for identification and the order, family, genus, species and numbers recorded. The invertebrates were further categorised into beneficial, predatory and pest species. The results of the study will be discussed.

DEFRA 2002. Action plan to develop organic food and farming in England. DEFRA, London pp20.

Hole, D.G., Perkins, A.J., Wilson, J.D., Alexander, I.H., Grice, P.V. amd Evans, A.D. 2005. Does organic farming benefit biodiversity? Biological Conservation 122, 113-130.

Soil Association 2002. The biodiversity benefits of organic farming. Soil Association, Bristol. pp40.

TECHNICAL SEMINAR 21: Improving crop health management – Arable, Talk 2

Vegetable Module Propagation – The Transition From a Conventional Propagation System to Organic Propagation

Roger White, Westhorpe Ltd, UK

Systems for raising and planting of vegetable transplants worldwide are now almost entirely module raised compared with traditional bare root transplants. In this paper I shall describe the conventional module propagation system based on non organic inputs which include non organic peat based compost, inorganic fertilisers, chemical seed dressings and the widespread use of foliar pesticides during propagation. I then outline the constraints encountered in organic module propagation and resolution of these constraints through a programme of planned research under the ‘Quality Low Input Food’ Project and at the Stockbridge Technology Centre.

Module propagation is based on the use of standard sized module trays. These have dimensions of 600 mm x 400 mm, are constructed of polypropylene and are friendly to the plant, the user and the environment. With individual cell volumes of from 10 cc to 90 cc and plant densities of from 332 to 2400 plants per square metre the system provides an opportunity to either reduce costs by selecting high density trays or in selecting low plant densities to improve field establishment and earliness.

Conventional propagation systems have been developed to reduce unit costs and rely upon peat based composts containing inorganic fertilisers and trace elements. Furthermore these peat based composts come with guarantees of freedom from plant diseases such as Clubroot, Wirestem (Rhizoctonia) and Xanthomonas. In addition many buyers also require freedom from human diseases, i.e. Ecoli, Salmonella and Listeria. These demands by buyers for guaranteed freedom from plant and human pathogens serves to explain in part why composts based on green waste are currently unacceptable. The demands of the market to drive down costs by reducing module (cell) size and increasing plant density increases greatly the risk to disease. Thus high density systems require high quality seed, typically each seed has a chemical seed dressing containing: Thiram, Metalaxyl, Iprodione and Carbendazim, and may also be treated with Imidacloprid (for aphids) and Chlorpyrifos (for cabbage rootfly).

Following seed germination these intensive conventional systems require further foliar pesticide treatments to control; seedling diseases, Rhizoctonia, Downy Mildew, Xanthomonas, Ringspot and many other foliar diseases. These fungicides are applied in conjunction or independently of aphicides, caterpillar sprays and even slug treatments. In total an individual module crop may receive as many as 10 different chemical treatments.

The conventional module compost contains N, P, K and trace elements. These nutrients in the compost are supplemented with inorganic fertiliser treatments based on Potassium Nitrate, Ammonium Nitrate and trace elements. These fertilisers are applied in liquid form, are applied at low nutrient levels and as such are low cost inputs. A starter fertiliser solution is applied immediately in advance of planting.

Following the introduction of Eurep-Gap accreditation the propagator has also to provide the buyer with complete traceability from sowing to planting. Under a new EU directive, taking effect from January 2005 all fruit and vegetables marketed within the EU must be fully traceable from propagator to consumer.

Consequently all sowings (conventional or organic) are now given a unique batch number and under this batch number records are maintained of all inputs.

With extreme pressure from the large supermarkets for producers to reduce costs the challenge confronting the organic propagator is to reduce cell size and to increase plant density. The inevitable implications of such a strategy are to reduce plant costs per hectare but to substantially increase the incidence of disease. The challenge for the organic propagator is therefore to reduce module cell size and control any increased disease risk.

Technically it is possible to obtain organic compost based on a blend of peat, coir, bark and clay. The only problem is that as the percentage of peat is reduced costs of the compost increases as does fertiliser costs and the management expertise required. However, with organic compost now supplied free of human and plant pathogens suitable composts capable of producing high quality plants are available, but at an increased cost.

Aside from the dramatically higher costs of organic liquid fertilisers based on fish meal, molasses or Lucerne nutrition of organic transplants is technically feasible, albeit, more demanding in terms of management expertise required, thus nutrition or organic modules is no longer a constraint.

Our experience has been that low quality seed represents the more serious constraint to successful and low cost organic transplant propagation. Why should the International seed trade apply up to four chemical treatments to the majority of brassica seeds if it is not required. Aside from the shortage of organic seed of those varieties demanded by the supermarkets, organic seed from some sources may also be of lower quality. This is not to infer criticism of the seed trade but to recognise the extreme difficulty of producing the highest quality organic seed in all climatic conditions.

A still further problem can be the unreliability of untreated seed. It is not enough to simply compare germination percentages; also it is essential to compare the vigour of seedlings at 6 and 10 days from sowing. In an attempt to resolve these fundamental seed related constraints under the QLIF project we shall be seeking to identify appropriate seed disinfection and seed treatments for organic production systems. To date the only successful method of containing seed quality problems is to ensure adequate disinfection of module trays linked to the use of only high quality compost, and above all purchase of the highest quality seed.

In 1991, the first year that we attempted to grow organic modules, we feared downy mildew more than any other disease. Indeed at the outset we thought that it would not be possible to grow brassica modules without significant losses from downy mildew. Over time we have learnt to live with mildew which with appropriate management we have found that it is possible to contain downy mildew to “an occasional problem” status. This has been achieved by a combination of:

· Appropriate sowing dates.

· Use of high vigour, high quality seed.

· Avoidance of a green bridge (never place freshly sown seedlings next to established seedlings).

· Use only high quality greenhouses with adequate ventilation.

· Avoid hot and humid conditions.

· Water plants early in the day – ensure the foliage dries rapidly.

In a situation where there are no approved organic fungicides we have found that Spanish tunnels provide the perfect environment for containing downy mildew. It may, following research at Stockbridge Technology Centre and at Lancaster University be proven that specific light transmission characteristics of certain plastics can also be used to further limit the incidence of downy mildew.

Although the propagator is invariably blamed for Rhizoctonia (Wirestem) this is primarily a field problem. Conventionally the disease can be limited by adequate tray sterilisation and a drench of Basilex (an O.P.). Whilst not a serious problem, even in the over-wintered crop where it can be more serious the disease has been contained in organic crops by:

· Effective tray sterilisation.

· High quality compost.

· Biological control with Tricoderma.

· Select seed with good vigour.

· Good greenhouse ventilation.

· Avoid wet humid growing conditions.

Again the key to containment of this disease is the combination of good ventilation and a high level of management expertise.

Xanthomonas campestris is a classic seed borne disease, which with global warming could become more serious in the United Kingdom with warmer wetter autumns. It is critically important to buy seed only from a reputable seed company; avoiding susceptible varieties. Under the QLIF project there is a programme of research designed to develop appropriate seed disinfection systems.

Majestik, a natural plant extract and Savona, a soap solution are recommended for aphid control. In practice we have found neither particularly effective. Aphids are seldom a serious problem with natural predators rapidly invading the greenhouse. In conjunction with research at Stockbridge Technology Centre and Syngenta Bioline we have introduced ‘banker barley blocks’, with cereal aphids and parasitic wasps (aphidius sp). Although not totally successful with the parasitic wasps being reluctant to forage for aphids the use of pheromone sprays may improve the effectiveness of this technique.

Caterpillars, in particular Plutella (Diamond Back Moth) can be a localised problems. With good management caterpillars can be contained with Bacillus thuringensis but BT is relatively slow acting. Under the QLIF project we are exploring the feasibility of trap cropping to attract the pest away from seedlings.

Cabbage Rootfly, although not a serious problem in the conventional crop given the widespread use of either Chlorpyrifos seed dressings (Gigant) or a Chlorpyrifos drench (Dursban) of seedlings immediately prior to planting organic crops can be devastated in the field by this pest. Under the QLIF project we shall be evaluating a range of companion seeded crops.

P J Salter, National Vegetable Research Station.

Advantages and Disadvantages of ‘Module’ Raised Vegetable Plants. Scientific Horticulture, 1982, Vol 33, pp 76-81.

Propagating and Transplanting Vegetables MAFF 1981.

TECHNICAL SEMINAR: Improving crop health management – Vegetables, Talk 1

Related to QLIF WP 3.2 (3.2.4)

Integrated Crop and Pest Management in sustainable agriculture in new member states: Case studies on horticulture crops in Poland

Zbigniew T. Dabrowski

The economic downturn in agriculture in new member countries which have passed through political and economic transition has forced farmers to dramatically reduce the chemical inputs used in agriculture, inadvertently contriibuting to an increase of the environmental sustainability (Dabrowski and Wiech 2003a). However, this reduction of agricultural inputs has affected the economic and social sustainability of the sector in meeting high demands for quality products exported to the EU countries (Dabrowski and Wiech 2003b) The author presents critical evaluation of achievements and constraints in involving all stakeholders (government authorities, scientists, extension service and farmers) in facing this new challenge in the production and protection of horticulture crops in Poland. Development and implementation of the Integrated Crop and Pest Management (ICPM) as the core of the integrated management of horticulture crops was the first step to produce safe and high quality crops. The concept and priority of ICPM programmes in Poland should be yield increase in regard to quality and quantity, however avoiding pesticide dependency as a pre-condition for this sustainable intensification of horticultural production (Dabrowski 2001). Also the implementation of alternative strategies to pesticides for crop production is expected to provide valuable information for the currently very small, but rapidly developing organic farming sector in Poland and other new member states. Recent Government involvement in expanding implementation of ICPM in Poland is presented.

Dabrowski Z.T. 2001. [Indices and criteria used in the evaluation of integrated pest management programmes]. Prog.Pl.Protection/Post.Ochr.Rośl. 41 (1): 77 –87.

Dabrowski Z.T., Wiech K. 2003a. Economies in transition and integrated pest management on vegetables: The case studies in Poland. IOBC wprs Bulletin 26 (3): 259-264.

Dabrowski Z.T., Wiech K. 2003b.Quality requirements by consumers determing needs for Integrated Pest Management on vegetable crops in Poland. Ann.Warsaw Agricult.Univ. – SGGW, Horticult.Landsc.Architect. 24: 5-13

TECHNICAL SEMINAR: Improving crop health management – Vegetables, Talk 2

The use of Bioinoculants and Biostimulants to reduce nutrient and pesticide requirements

D.J. & M.T.M. Hudson, Biotechnica Services Ltd, UK

The effects of a combined approach to introducing or restoring a range of beneficial microbes both into the soil and onto the crop canopy have been studied in field trials. The approach entails an initial detailed soil analysis providing data on macro and micro- nutrients, CEC, pH, texture, organic matter and relative balances of cations. This enables an initial assessment of the soil’s ability to sustain a balanced microbial population. Amendments are made as indicated by the analysis and may include pH adjustment, balancing of cations to release locked up nutrients, together with the use of a cover crop and/or incorporation of organic matter as compost or as soluble humic acid derivatives.

Population with beneficial bacterial and fungal species including mycorrhiza are then introduced into the soil under controlled conditions and encouraged to form synergistic relationships in the root zone of the crop. This allows for a more efficient use of available nutrients and for a reduction in applied fertilizer. At the same time the plant is protected against diseases by the presence of the benign biomass, which restricts the ability of pathogens to proliferate and to invade the plants root system. Similar conditions can be created on the plant’s foliage helping to minimize opportunities for airborne fungal spores to thrive even when they are deposited on the leaf. These approaches enable reductions in the use of soil sterilants and in chemical fungicides.

The results indicate that the use of this approach known as Bioagronomy can allow for reduced inputs without sacrificing crop yield or quantity.

Lindermann R.G. 1992. Vesicular-arbuscular Mycorrhiae and soil microbial interactions. American Society of Agronomy special publication No. 24

Larkin R.P. 2003 Characterisation of soil microbial communities under different potato cropping systems by microbial population dynamics. Soil Biol. Biochem. 35: 1451-1466.

Collier R.A. 2004 To evaluate efficacy of biological products under high Potato Late Blight disease pressure in Jersey. Private commercial report.

TECHNICAL SEMINAR: Improving crop health management – Vegetables, Talk 3

Quality and yield of organic apples due to soil and fertility management

Hanne Lindhard Pedersen

Apple is the commercially most important top fruit crop grown in the EU. Pest and disease, in particular apple scab, fruit tree canker, apple sawfly and rosy apple aphid are the main reason for commercial crop losses. Competition for nutrients by weeds and the ground cover vegetation is another main reason affecting fruit quality and marketable yield.

High quality in organic apple production usually depends on high levels of permitted pesticide use which themselves may raise consumer concern due to known environmental impacts.

Previous research has shown that in “minimum pesticide use” organic systems the best fruit quality and lowest pest and disease incidence is found in orchards where trees are grown in an alley-way system, with grass grown-cover between row of trees, at relatively “low” nitrogen supply (Lindhard Pedersen and Bertelsen, 2002). However, this also produced insufficient yield levels.

Fruit yield and fruit quality in organic apple production is controlled by a multitude of interacting agronomic factors, most importantly is water, tree arrangement and density and nitrogen input levels and availability pattern during the growing season.

Interactions between fertility management protocols and planting density with respect to yields, disease incidence and fruit quality characteristics of apple trees are investigated in ongoing research. Results on tree growth, soil water content, nitrogen content in soil and leaves, infections of actual pest and diseases, yield, fruit size and colour, fruit firmness and sugar content for 6 fertility management systems and 2 varieties are presented for the first research year.

Lindhard Pedersen H. and Bertelsen M. 2002. Alleyway groundcover management and scab resistant apple varieties. ECO-FRU-VIT. 10th International Conference on Cultivation technique and Phytopathological problems in Organic Fruit-Growing and Viticulture. P. 16-21.

TECHNICAL SEMINAR: Improving crop health management – Fruit, Talk 1

Related to QLIF WP 3.5 (3.5.1)

Organic Apple Production – Varieties and Integrated Pest and Disease Management in the UK

Stella Cubison et al., Henry Doubleday Research Association, UK

Organic apple growing in the UK is a particularly challenging area of organic crop production. Pest and disease problems and a lack of suitable varieties result in low and erratic yields of poor quality fruit. The volume of UK production is very small - only a handful of large-scale producers currently supply supermarket and processor requirements. However, demand for organically grown fruit has risen dramatically in the past decade and is currently satisfied largely through imports. In order to increase the volume of home-grown fruit, better controls for the major pest and disease problems associated with apple production need to be developed.

This five-year horticulture LINK project, funded by DEFRA, aims to develop an effective integrated pest and disease management programme for organic apple production in the UK. Now nearing completion, the project has explored the use of cultural pest and disease control methods, whilst optimizing the use of organically permitted plant protection products. The main focus has been to develop suitable control strategies for the major diseases scab and mildew and the pest rosy apple aphid. Varieties of dessert, processing and juicing apples most suited to organic production have also been identified. This paper gives a brief outline of the approaches used in the project and discusses the key findings to date.

Firth C. and Lennartsson M. (1999). Economics of organic fruit production in the UK

MAFF project no. OF0151. HDRA, Ryton Organic Gardens, Coventry

Cubison S. and Cross J. (2004). Varieties and Integrated Pest and Disease Management for Organic Apple Production in the UK. BGS/AAB/COR 2004 Conference: Organic Farming – science and practice for profitable livestock and cropping. BGS Occasional Symposium No. 37. pp192

TECHNICAL SEMINAR: Improving crop health management – Fruit, Talk 2

Integrated control of soilborne and foliar pathogens in organic greenhouse crops

C. Giotis et al., TEI of the Ionian Islands, Greece

Experiments focused on testing novel control methods for corky root rot (Pyrenochaeta lycopersici) and cucumber powdery mildew (Sphaerotheca fuliginea) were carried out in England and Greece respectively.

The treatments compared against corky root rot in the trials in England were: soil steam sterilization, grafting on resistant rootstock, soil amendment with antagonistics microorganisms (Pythium oligandrum and Bacillus subtillis) and soil amendment with cow manure compost, housewaste compost, conifer extracts, fish emulsion, seaweed extracts, brassica residues, and chitin.

Significant control against the corky root rot was achieved by steam sterilization, grafting on resistant rootstock, cow manure compost, housewaste compost, brassica residues and chitin.

The treatments compared against cucumber powdery mildew in the trials in Greece were: foliar sprays of the fungal antagonistics Ampelomyces quisqualis (AQ10) and Pythium oligandrum (Polyversum), a plant extract from the giant knotweed Fallopia sachalinensis (Milsana VP 2002), and chitin.

Milsana and chitin were very effective against powdery mildew while the two antagonistics did not provide significant control of powdery mildew.

Results from both experiments will be presented in the conference.

Giotis, C. and Leifert, C. (2001) Control of fungal diseases in Organic crop production systems. In: Proceedings of the EU-IMPROBIOSEED workshop on: Non-chemical protection of plants against diseases. Heraclion, Crete, 2001.

Ghorbani, R., Giotis, H., Wilcockson, S and Leifert, C. (2005) Control of late blight in organic potato production systems. Pesticide Review in press

TECHNICAL SEMINAR: Improving crop health management – Glasshouse crops, Talk 1

A practical approach to pest management in organic glasshouse tomatoes

Juan Rodriguez

Economical constraints in organic glasshouse crop production imply that only a limited number of break crops are feasible to alternate with tomatoes. Moreover, some of these harbour similar pest problems and therefore do not contribute to reduce the pest pressure for the following crop. Thus, pest control strategies have to focus on other aspects such as crop husbandry, biological control and the limited use of permitted pesticides for corrective actions.

Cultural and preventative measures play a key role for the success of pest management in an organic glasshouse environment. This is crucial for pest such as mealybugs and woodlice where no effective biological control agents are commercially available. Prompt and accurate plant monitoring and pest identification are essential. This includes increasing staff awareness and implementation of plant monitoring techniques with the help of sticky traps and localisation maps.

The biology and release methods of the natural enemies available for the control of the major tomato pests in the UK (whitefly, leafminer and two spotted spider mite) are described in order to get a better understanding of plant - pest - beneficial interaction. Special attention has been paid to the benefits and limitations of the most effective biological control insects used commercially. In this respect, the side effects of sulphur used for powdery mildew control on parasitoids and the build up of the predator Macrolophus caliginosus to damaging levels, suppose probably the biggest challenges in relation to pest control for most commercial glasshouse growers in Northern Europe.

Malais, M. H. and Ravensberg W. J. (2003). Knowing and recognising. The biology of glasshouse pests and their natural enemies. Koppert, Berkel en Rodenrijs,

Helyer, N.; Brown, K. and Cattlin, N. D. 2003. A colour handbook of Biological control in plant protection. The Royal Horticultural Society. Manson Publishing, London 2003.

Jackel, B. Schmidt, H. U. 1999. Plant extracts: possibilities and limitations. 2. Reduction of damage by pests and effects of plant extracts on non-target organisms. Gesunde Pflanzen. 1999. 51: 4, 101-108. 7 ref.

Sterk, G. Heuts, F., Merck, N. and Bock. 2002 Sensitivity of non-target arthropods and beneficial fungal species to chemical and biological plant protection products: results of laboratory and semi-field trials. In 1st International Symposium on Biological Control of Arthropods.

TECHNICAL SEMINAR: Improving crop health management – Glasshouse crops, Talk 2