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Veenkoloniale boeren moeten het gat vullen dat ontstaat door het wegvallen van inkomenssteun uit Brussel. Innovatieprogramma Landbouw Veenkoloniën draagt eraan bij met elf innovatieprojecten.

Door kordate ketensamenwerking heeft de uiensector kwaliteitsonderzoek in de benen gekregen. Met ook als resultaat: de rassenlijst blijft bestaan. De plannen zijn groter dan ooit.

Binnen het project ‘Bodem in Balans?’ begon een groep telers uit het noorden van het land met de methode Albrecht voor bodemanalyse. De studieclubleden wilden weten wat ze konden bereiken met Albrecht als uitgangspunt. Lopende het project werd het accent verschoven naar een compleet weerbaarder teeltsysteem.

Reduced tillage can improve soil physical quality relative to mouldboard ploughing by lessening soil disturbance, leaving organic matter at the soil surface, and stimulating soil biological activity. In organic farming, continuous ploughing may negate benefits to soil structure and function from increased use of manures and more diverse crop rotations, which are particularly important components of organic farming. The current study examined soil physical quality (i.e., properties and functioning) of a 4-year old reduced tillage system under organic and conventional farming with crop rotations that included root crops. Reduced tillage was compared to conventional mouldboard ploughing (MP) in 2 organic fields at different points of the same crop rotation (Org A and Org B) and 1 conventional field (Conv A). Reduced tillage consisted of non-inversion tillage (NIT) to 18–23 cm depth whereas MP was characterised by annual mouldboard ploughing to 23–25 cm depth. NIT improved soil water retention in Org B but had no effect in Org A. NIT increased soil aggregate stability at 10–20 cm depth compared to MP in all fields, and additionally at 0–10 cm in Conv A. Penetration resistance was higher in NIT in all fields. Furthermore, soil organic matter content was higher in NIT than MP at 0–10 cm depth in all fields and at 10–20 cm in Org B and Conv A. NIT increased carbon stocks in Org B but not in Org A. NIT statistically increased crop yields in spring wheat/faba bean mixture in Org A, and there was no yield penalty from NIT in Org B spring wheat nor Conv A sugar beet. In contrast, field-saturated hydraulic conductivity in all fields in autumn was lower in NIT. Differences in crop (i.e., phase of rotation) and associated organic inputs between Org A and B likely accounted for the differences in effects of tillage system. Overall, the NIT system improved or imposed no penalty on soil physical quality (except field-saturated hydraulic conductivity) and improved or imposed no penalty on crop yields and could therefore be considered as a viable alternative for farmers.

De topsectoren zijn van groot belang omdat hierbij actief wordt ingezet op de negen sectoren die voor Nederland BV erg belangrijk zijn. Het midden- en kleinbedrijf (MKB) neemt hierin een sleutelpositie in en kan binnen de topsectoren een rol vervullen die cruciaal is voor onze economie. De sector van de Tuinbouw en Uitgangsmaterialen bedraagt wel 10% van het bruto nationaal product (BNP). Ook andere Topsectoren, met name Agri&Food, zijn belangrijk voor specifiek de plantenziektekunde en voor de plantaardige productie als geheel. In dit artikel wordt ingegaan op het KNPV najaarssymposium ‘Plantenziektekunde in de Topsector op 19 november 2014.

Maurits Bax uit Luyksgestel werkt met de Yara N-sensor. Zo spuit hij minder dan een derde van de voorgeschreven dosering voor loofdodingsmiddel in aardappelen. Andere toepassingen zijn minder praktijkrijp, zoals aardappelen bijmesten. Daarvoor lijkt een app, ontwikkeld door het PPO, uitkomst te gaan bieden. PPO Lelystad begeleidt het project waar Bax aan mee doet. De teler kreeg de afgelopen twee teeltseizoenen voor zijn aardappelen een adviesgift van PPO op basis van twee systemen: de BemestingsNavigator aardappel van Altic en een systeem dat PPO ontwikkelt. De volgende toepassing was voor het spuiten van halmverstevigers in zomergerst.

Catalogus van de Aardappeldemodag in Westmaas. het thema van 2014 luidt 'Schone teelt bepaalt de toekomst'

Praktijkonderzoekbedrijven zijn niet meer weg te denken uit de Nederlandse akkerbouw. Wat betekenen ze voor de sector? Akker neemt een kijkje in de keuken van de proefboerderijen in Nederland. In dit nummer als laatste proefbedrijf Kollumerwaard, een proefboerderij met de focus op pootaardappelteelt en bodemonderzoek.

Een mooie zomerse woensdag in augustus 2012 stond garant voor een zeer geslaagde Aardappeldemodag in Westmaas. In totaal trok de happening 6.000 bezoekers. Ze konden hier een veelheid aan demonstraties bewonderen en een berg informatie tot zich nemen bij de in de totaal 130 standhouders. Daartussen waren sectorbreed noviteiten te zien, waarvan een overzicht in woord en beeld is gemaakt.

Half augustus 2011 stond proefboerderij Vredepeel een dag lang in het teken van aardappelteelt op zandgronden. Aan de hand van live demonstraties, proefvelden en voorlichtingsstands konden bezoekers zien dat het verbouwen van aardappelen in veel opzichten een aangepaste mechanisatie en teelttechniek vraagt. Nog schoner rooiende rooimachines en banden die altijd op lage spanning mogen blijven, waren voorbeelden van enkele interessante noviteiten.

Measurements of the water boards have shown that pesticide concentrations in surface water have decreased less than was expected based on model calculations. Possibly, the implementation of spray drift reducing techniques is overestimated in the model calculation. The impact of point sources is probably underestimated. A project was initiated for the quantification and qualification of possible point sources in Dutch agriculture. Several point source entries were identified: e.g. internal and external cleaning of sprayers, filling stations and discharge of transport water from fruit sorting installations. A method was developed to discriminate the contamination of the pesticide activities in their possible impact on surface waters; the POint Source SUrface waters Model (POSSUM).

De maisteelt kent veel ontwikkelingen. Laudis is het nieuwe gewasbeschermingsmiddel en niet-kerende grondbewerking wint terrein

De LNV-raad namens Nederland voor de Filippijnen is drs. Adriede Roo. Nog niet zo lang geleden overlegde hij met de minister van landbouw van de Filippijnen over mogelijkheden om op de eilanden aardappelen te telen die geschikt zijn voor verwerking.Dit om deviezen te sparen en om lokaal meerwaarde aan de aardappelketen te geven. Ook is gesproken over een mogelijke rol voor het Nederlandse bedrijfsleven in dit voorstel. Aan onderzoekers van Wageningen UR, Anton Haverkort en Romke Wustman, is gevraagd om de haalbaarheid hiervan uit te zoeken.

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is one of the most important pest species of maize in several countries of Central and Eastern Europe. This pest insect has invaded from the USA and is mainly controlled by insecticides in the EU. In the USA reliance on insecticides seems to decrease due to transgenic maize production. The EU project Diabr-Act aims at establishing a harmonized and sustainable control strategy for western corn rootworm populations in Europe. In this respect, current chemical control strategies used in the USA and EU are described. Seed, soil and foliar treatments as well as transgenically protected maize are discussed. Specific attention is given to insecticide resistance. Seed treatment has clear environmental benefits, but factors influencing the efficacy should be declared. Soil and foliar treatments have perspectives, though new technologies limiting environmental hazards should be considered. Transgenic maize may have serious perspectives

Het is mogelijk om de emissie van maïsherbiciden naar het oppervlaktewater terug te dringen. Dat blijkt uit bemonstering van oppervlaktewater in twee Brabantse gebieden. Het aantal overschrijdingen van de maximale toegestane concentratie is er in 2009 sterk afgenomen.

Verlagen van de fosfaatgebruiksnorm heeft nog geen invloed op opbrengsten, blijkt uit onderzoek. Op zand is echter minder snijmais door lage fosfaatgiften

Goede ideeën brengen het lang altijd niet tot brede toepassing in de praktijk en vaak duurt de weg ernaar toe erg lang. Om versneld interessante methoden en technieken voor geïntegreerde gewasbescherming te kunnen ontwikkelen en introduceren, heeft het ministerie van LNV aan Wageningen UR gevraagd hiervoor een stappenplan te ontwikkelen. Al zeven jaar wordt volgens deze lijn aan verduurzaming gewerkt.

The carrot fly (Psila rosae) is a major pest of umbelliferous crops, particularly in carrot production. This pest is present in temperate regions of Northern and Western Europe and also in the warm and dry climate of Central and Southern Europe. Currently, control strategies are limited and there may be a bottleneck of pest control solutions in the future. In practice, growers in the Netherlands mainly rely on a commercial, supervised control system which monitors the carrot fly population pressure. Possibilities to control the carrot fly after exceeding an economical threshold are reduced due to a lack of efficient chemical insecticides. Another option is the use of seed treatment to protect the carrots against the larvae developed from the first flight of the carrot flies for 12¿14 weeks after sowing. The state of the art of the carrot fly pest and control possibilities are hereby discussed. Bottlenecks in control of carrot flies are highlighted and described

Afrikaantjes bestrijden wortellesieaaltjes beter dan wilde haver, stelt PPO Lelystad. Maar afrikaantjes zijn slecht in de meeste bouwplannen in te passen

The effect of the amount of nitrogen applied and of the method of application on the amounts of phosphorus and potassium removed from the field with the product in cauliflower cultivation was studied in three field experiments. Band placement or split application of nitrogen did not influence phosphorus or potassium uptake. At optimum nitrogen application, an average of 17 kg of phosphorus (P) and 129 kg of potassium (K) per hectare was removed from the field with the product at harvest. Calculation of nutrient removal by cauliflower based on nutrient content and fresh yield weight is not possible, because fresh yield weight of cauliflower is not normally determined. Variation in amounts of phosphorus and potassium removed from the field appears limited. Therefore fixed amounts of 20 kg of phosphorus and 130 kg of potassium per hectare are proposed for the amounts of phosphorus and potassium removed from the field with the product in cauliflower cultivation.

Artikel n.a.v. rapport ' Perspectieven van sojavervanging in voer : op zoek naar Europese alternatieven voor soja ' PPO -project 3250119600

De veldspuit moet je elke dag of bij verandering van middel reinigen. Dat kan met de hand, maar halfautomatische en automatische spoelsystemen sparen tijd. Alle wasprogramma¿s krijgen de spuit schoon, maar er zijn verschillen, ondervonden LandbouwMechanisatie, PPO Vredepeel en DLV Plant tijdens een vergelijking

A series of field trials were carried out from 2000 to 2003. Neonicotinoid insecticides applied as seed potato treatments at planting were tested to control wireworms in potato crops. Compounds were applied as drench or spray. Neonicotinoids tested were imidacloprid at rates of 35, 70, 88, and 175 g a.i.; thiamethoxam at 17.5, 35, 50, 70, and 140 g a.i.; and thiacloprid at 72 and 144 g a.i. per metric ton seed potatoes. Treatment with imidacloprid at 70 g/ton seed and thiamethoxam at 50 g/ton seed showed significant control of wireworms at harvest but thiacloprid showed insufficient protection. No phytotoxicity was recorded at harvest. Prospects and benefits of seed potato treatments with neonicotinoids are discussed, including lowering of the amount of insecticide needed for adequate protection

Taking field margins out of intensive cultivation is a common form of agri-environmental scheme and on-farm nature management. Typically, no nutrients or pesticides are applied in these margins, which may be sown either with a crop or with grasses and native flowering plants. In some cases the margins are mown, while in others they are left alone. Newly established grass margins are less species-rich than field boundaries or road verges with a long history, justifying the expectation that field margins, if properly managed and given time and appropriate seed sources, could develop into relatively species-rich vegetation. We studied the biodiversity of both margins taken out of production and adjacent ditch banks in the years following initial establishment of the margins. To this end we combined the data of three different projects in order to increase the sensitivity of the statistical analyses. The results showed that the plant species richness of the field margins increased in the years following establishment over a period of four years. In addition, shifts in species composition indicated a decrease in soil nitrate concentrations. The species richness of both butterflies and dragonflies may increase. The most striking result was the marked increase in the plant species richness of the adjacent ditch banks in the five years following creation of the margins. Here, too, changes in species composition indicated a decrease in soil nitrate. In the years following establishment of the field margins there was no increase in the cover of agriculturally harmful weeds in these margins. However, the number of harmful nematodes increased. Our results show the short term effect of establishing field margins. Long term effects are still in need for further research.

To test the effects of the growth regulator trinexapac-ethyl (Moddus 250 EC) in the main seed crop of grasses in the Netherlands, 10 field trials were conducted in perennial ryegrass ( Lolium perenne L.). These field trials were carried out in first and second seed harvest crops during 1999–2002. Four rates of Moddus (untreated, 0.4, 0.8 and 1.6 L product ha −1 ) were applied at the start of stem elongation (DC 30–31, zero to one node) during the first two years. In addition, the effect of timing of the application of 0.8 L Moddus ha −1 was studied (untreated, DC30–31, DC31–33, DC33–37). In most trials, in addition to the normal amount, 45 kg N ha −1 extra spring nitrogen was applied. The work reported is valuable, and has relevance to all areas of the globe where this perennial ryegrass is grown for seed, e.g., northern Europe, the US (particularly, Oregon), New Zealand, Australia, Chile and Argentina. Crop development in spring was partly affected by weather conditions during the previous autumn and winter, so while Moddus was applied at the same crop development stage, the calendar dates varied for the different harvest years. Temperature sum from 1 November accounted for only 51.4% of the variation. Applications at higher rates increased the reduction of stem length, lodging of the crop and the density of panicles. Application later than DC30–31 resulted in shorter culm length and higher total dry matter weight of the crop. The application of the highest rate of Moddus (1.6 L ha −1 ) at the crop development stage DC30–31 never resulted in an unacceptable final phytotoxic effect. Effect of Moddus on seed yields was inconsistent; the potential seed yield increase was about 10%. In general, there was no significant interaction between the application of 0.8 L Moddus ha −1 at the crop development stage DC30–31 and the spring nitrogen rate. The results show that DC31–33 is the best time to apply 0.8 L Moddus ha −1 . In second seed harvest crops of lawn types applying 0.8 L Moddus ha −1 together with increasing the amount of spring nitrogen can be considered.

In a field experiment on an abandoned asparagus field we studied the effect of Biological Soil Disinfestation (BSD) on survival of buried inoculum samples of three test pathogens (Fusarium redolens f.sp. asparagi (FRA), Rhizoctonia tuliparum (RT) and Verticillium dahliae (VD)) and on the Fusarium infestation level. The BSD treatments involved incorporation of grass into moist soil and covering the soil with airtight plastic. The amount of grass incorporated was varied (42, 62 or 102 tons of grass/ha) as well as the depth of incorporation (40 or 80 cm). It was found that BSD greatly reduced all three pathogens in buried soil samples and that incorporation of 62 or 102 tons of grass per ha to 80 cm soil depth resulted in a significant decrease in soil infestation in the upper 40 cm; in the deeper layer the decrease was lower. Asparagus plants grown from seed in the field for one year showed a strong decrease in Fusarium root rot severity with all BSD treatments. The results clearly show the potential of BSD to decrease soil infestation levels of Fusarium pathogens and to contribute to an enhanced life span of replanted asparagus crops

A discussion is presented about the patterns in the present year-round supply of vegetables to large cities in the Red River Delta in North Vietnam. Especially during the hot summer season, vegetables are supplied from Dalat in South Vietnam or from Kunming Province in China. Generally speaking, importing vegetables from far away areas or foreign countries adds considerable cost to the product, while extensive transportation decreases product quality or limits the number of products that can be supplied. Aiming for more attractive consumer pricing, an increase in product quality and year-round product availability, options are explored for the regional year-round supply of vegetables from North Vietnam itself. The discussion is based on the agro-ecology of vegetable crops, on market opportunities during the year and on environmental considerations. It is argued that most of the vegetables presently available in the Red River Delta can be supplied from areas in North Vietnam itself. Special attention is given to environmental considerations to ensure sustainable production

Weed control within crop rows is one of the main problems in organic farming. For centuries, different weed removal tools have been used to reduce weeds in the crop rows. Stimulated by the demand from organic farmers, research in several European countries over the last decade has focused on mechanisation using harrowing, torsion finger weeding and weeding with compressed air (Pneumat). Intelligent weeders are now being developed which offer more advanced ways to control weeds, including larger ones and to leave the crop plants unharmed. One of the first commercially available intelligent weeders, the Sarl Radis from France, has a simple crop detection system based on light interception, which guides a hoe in and out of the crop row, around the crop plants. The inclusion of innovative technologies, including advanced sensing and robotics, in combination with new cropping systems, might lead to a breakthrough in physical weed control in row crops leading to significant reductions, or even elimination, of the need for hand weeding.

With the changing position of agriculture in the world the challenges for weed management and weed science are changing as well. In this paper recent developments in weed science with respect to several aspects of weed management are discussed in relation to those changes. Developments in cultural weed control or prevention, chemical weed control with emphasis on precision in time and space and mechanical control are discussed. These developments are put in the framework of historical changes in the demand for specific solutions in weed management. Future challenges for weed science are discussed in relation to the changing position of agriculture in the world.

Aardappelsymposium legt toekomstige uitdagingen bloot

A pilot on 400 ha of Dutch arable farms during 2004-2007 perennial grassy field margins and functional annual flower strips were created on potato and wheat fields. Monitoring information on pests and natural enemies was directly communicated to the farmers to support pest management decisions. Due to the increasing numbers of natural enemies and the gradually reducing peak densities of aphids, the farmers could refrain from insecticide applications against aphids in these crops. The pilot has yielded great public awareness on possibilities for functional agro biodiversity in arable crops.

Recentelijk zijn enkele doorbraken gerealiseerd op het gebied van biomassa-afhankelijk doseren in open teelten. Het gaat hierbij om plaatsspecifieke dosering van bepaalde herbiciden en fungiciden op basis van de hoeveelheid bovengrondse biomassa onder de spuitdoppen. Om dit effectief te maken, zijn toegesneden sensoren, beslisregels en spuitapparatuur nodig. Plaatsspecifieke dosering van loofdodingsmiddelen in consumptieaardappelen is nu praktijkrijp middels MLHD-PHK (Minimum Lethal Herbicide Dose-Potato Haulm Killing) in combinatie met de N-sensor (stikstof-sensor), of SensiSpray. In de testfase werd een reductie van gemiddeld 50% in het gebruik van loofdodingsmiddel t.o.v. gangbare praktijk bereikt. In dit artikel wordt een overzicht gegeven van onderwerpen op het gebied van biomassa-afhankelijk doseren van gewasbeschermingsmiddelen waarbij de Plant Science Groep (PSG) van Wageningen UR trekker van de ontwikkeling is.

Nog even en dan kleuren de strak getrokken aardappelruggen weer groen. Tijd om de laatste ontwikkelingen op het gebied van phytophthorabestrijding, en de nieuwe gewasbeschermingsmiddelen, op een rijtje te zetten. Al is de essentie van de boodschap van phytophthora-onderzoeker Huub Schepers niet anders dan anders: preventie, preventie, preventie.

The effects of stale seedbed preparations and several weed control methods on the emergence of weeds in lettuce were studied. The specific goal was to evaluate the use of a stale seedbed in combination with chemical or mechanical weed control methods in the field. Depending on location and year, stale seedbed preparations followed by weed control prior to planting reduced the amount of weeds during crop growth by 43¿83%. Control of the emerged seedlings after a stale seedbed preparation was more effective with glyphosate than with a rotary harrow. Covering the rotary harrow during control to prevent light reaching the soil improved its effect on the weed density during crop growth in two of 3 years. Radiation with far red light (FR) did not reduce the number of emerging weeds in this study. Mechanical control by finger weeder, torsion weeder and hoe was applied without stale seedbed preparations. These measures reduced the weed densities by 88¿99%, compared with the untreated control and were more effective than chemical weed control with carbetamide and chlorpropham. The results show that the stale seedbed technique in combination with mechanical control of emerging weeds can reduce the weed population during crop growth as effectively as chemical control. The technique may therefore help reduce the use of herbicides in lettuce crops in the future.

Voor de implementatie van een geïntegreerde geoptimaliseerde jaarrond beheersingsstrategie is nog veel operationele kennis over de aardappelziekte nodig.Duurzame beheersing van Phytophthora infestans is pas mogelijk als de complexe onderdelen voldoende op elkaar zijn afgestemd en worden vertaald naar geïntegreerde praktische oplossingen. Binnen dit thema van het Parapluplan Phytophthora worden de resultaten uit de andere thema's vertaald naar praktische oplossingen. In dit artikel wordt een aantal van de projecten uit de Toolbox toegelicht

Solanum sisymbriifolium is an interesting trap crop to control potato cyst nematodes. A series of field experiments was carried out in the Netherlands between 2001 and 2003 to test its performance under field conditions. Experimental factors included sowing time, sowing density and site. Rate of germination, plant establishment and change over time in light interception were monitored. Growth analysis was performed at 7 and 14¿weeks after emergence, and dry weight of component plant parts was determined. Time to 50% emergence was 36-38¿days for planting at early April and declined to minimum values of ca 8-11¿days when planting took place in June, July or the first week of August. When planted later, time to 50% germination increased again. Time to 50% light interception showed a similar trend with sowing time; minimum time was 35-40¿days for planting between June and half of July. Planting before May did not advance crop growth. Crop performance was very variable across years and sites when planted later than the end of July to beginning of August. Dry matter accumulation up to 400¿g¿m¿2 was found at 7¿weeks after emergence and up to 1040¿g¿m¿2 after 14¿weeks. At 7¿weeks after emergence, dry matter production increased with planting density (range 50-400¿m¿2), but no statistically significant differences were found after 14¿weeks. A seed rate of 100¿m¿2 seems generally sufficient. Radiation use efficiency was 1.69¿g¿MJ¿1 PAR (SE¿=¿0.0208). Dry matter accumulation (2002-2003) was somewhat higher in Wageningen (51°58'N) on light sandy soil than in Flevoland (52°31¿N) on clay soil and in Drenthe (52°51¿N) on reclaimed peat soil. It is concluded that above-ground growth of S.¿sisymbriifolium in the Netherlands is adequate if planted between early May and the end of July

The effect of two different habitats, stored cowpea [Vigna unguiculata (L.) Walpers] pods and seeds, on the dispersal and functional response of Uscana lariophaga Steffan (Hymenoptera Trichogrammatidae) was investigated, with Callosobruchus maculatus (F.) (Coleoptera Bruchidae) eggs as hosts. In the presence of directional light from the top, parasitoids moved faster through columns filled with pods than through columns (either filled with pods or seeds) in darkness. The different habitats, seed or pods, did not have a significant effect on dispersal. The maximal dispersal rate of colonising U. lariophaga females may be up to several meter per day, and median net displacement rates are around 0.5 - 0.8 m per 24 h. The functional response of U. lariophaga could be described by Rogers (1972) random parasitoid equation as a Holling Type II curve and resembles the ones found in earlier experiments. At host densities below 40 eggs per cluster, U. lariophaga was more efficient at finding host eggs in a seed habitat than in a pod habitat, probably due to area restricted searching behaviour after oviposition. At higher host densities, U. lariophaga becomes egg limited, and neither walking behaviour nor the habitat structure significantly influence her foraging success.

Fluorescence can be used to measure and visualize the activity of herbicides that inhibit the photosynthesis. Glyphosate, although not acting primarily on the photosystems, appears to increase fluorescence of plants. We investigated whether fluorescence technology is a useful tool to both quantify and image of the performance of different adjuvants for glyphosate. A red laser beam providing equipment is used to scan black nightshade plants at a low and high light intensity. A cooled, integrating 16 bit CCD camera is used to record the fluorescence during the low level (Fo) and high level scan (Fm). The relative increase of fluorescence expressed as [(Fm—Fo)/Fm] 100 % is calculated and color images are produced. Glyphosate was applied at two suboptimal application rates of 16.9 and 33.8 g ae/ha at 200 L/ha. Both the influence of glyphosate rate and the influence of added adjuvants were obvious. The fluorescence data 30 h after treatment demonstrated that the adjuvants HM9121-A and HM9110 performed better than AMS, HM9541-A, HM9910, or HM2005-B. This observation was consistent over the next three observations (54, 78, and 102 h). The fluorescence data after 72 h correlated (R2=0.82; logarithmic regression) with the fresh weight reduction caused by the glyphosate treatments. The adjuvants HM 9121-A and HM9110 performed the best and the adjuvant HM9541-A had little effect on glyphosate performance. Both imaging and fresh weight data indicate that HM 9121-A performs somewhat better than HM9110.

A zonal centrifugation method, known as the Hendrickx centrifuge technique, was tested for routine detection of winter sporangia of Synchytrium endobioticum in soil. In four experiments the ability of the Hendrickx centrifuge to extract the sporangia from soil was compared with a method used by the Dutch Plant Protection Service, which is a modification of the recommended EPPO method. Naturally and artificially contaminated soil samples were used to study the recovery percentage of and variation in numbers of winter sporangia. The effects of soil type and inoculum density were studied. The Hendrickx centrifuge method, developed originally for extraction of free living nematodes from soil, performed better than the method used by the Dutch Plant Protection Service. This was due to a better extraction recovery (60% higher), a lower measurement error (50% lower) and a lower detection level (down to 0.02 sporangia g(-16) soil). The Hendrickx centrifuge method is much less labour-intensive than the method used by the Dutch Plant Protection Service. It can be used to extract many different organisms from soil, and DNA can be subsequently extracted from the supernatant for further PCR analysis. Inclusion of the Hendrickx centrifuge method in the official EPPO diagnostic protocol for regulated pests is recommended as an alternative method for detection of sporangia in soil