Annual report 2002 LBI organic fruit growing research

Overview of projects, project results, funding bodies and partners in 2002 and plans for 2003 Including: SOIL MANAGEMENT * Evaluation of leaf analysis in organic fruit growing as a tool for measuring the uptake of nutrients: Consultants and researchers exchanged practical experiences and the LBI hopes to work with target values. * Impact of sulphur stress: The fruit quality seemed to be better in the reduced sulphur treatment (27 kg /ha instead of 60 kg /ha after flowering). * Fertilisation: In a late summer fertilisation trial with Elstar, trees fertilised late summer/autumn have a higher nitrogen content in the bud the following spring. And fertilising just before winter leads to increased growth of weeds in the next season. * Ground cover: The key to white clover undergrowth is to ‘do it properly or not at all’. It is difficult for an organic grower to restore undergrowth which has been invaded by grasses to bare earth. Undergrowth is definitely not the answer for fruit growers who have any difficulty with mechanical weeding. The management of ground cover requires at least as much mechanisation as the bare tree strip. REGULATING GROWTH AND CROP * Steps to counter biennialism in Elstar: A trial was set up at three orchards combining various measures: thinning or not thinning with two or three applications of lime sulphur, adapted pruning, 3 levels of fruit bearing (30, 40, 50 tonne/ha) and early or late manual thinning. This trial should demonstrate the relative significance of the various measures. Flowering will be evaluated in the spring of 2003. * Fruiting spur pruning in Elstar: To obtain better insight into the effect of different pruning methods three pruning treatments were used: standard pruning, removal of an extra large amount of fruiting spurs, and removal of extra fruiting spurs but sparing smooth one-year-old shoots. The production of the trees has been estimated and the blossom will be evaluated in the spring of 2003. * Effect of thinning times, fertilisation and bearing on regularity of production and fruit quality in Elstar: Ripening was delayed by the high nitrogen dose and associated higher acid content. Despite the late ripening the firmness was still lower, the calcium content lower and the nitrogen content higher. All three factors pro- duce a clear deterioration in quality. On the other hand, the sugar and acidity were higher in this case, but both these values fall within the target band. The trial will continue in 2003 CANKER * Administering calcium hydroxide against Cancer through the sprinkler irrigation system: Despite its effectiveness, sprinkling with calcium hydroxide cannot as yet be generally recommended for practical application. All the difficulties stem from the fact that the agent does not really dissolve, and the suspension formed very rapidly settles out. FRUIT QUALITY * Optimum picking time for Santana: Santana is a relatively new variety, and further investigation is required into optimising cultivation and storage. The apples only developed their full flavour when picked some time after the point of physiological ripeness. * Sprinkling to combat sunscald: By sprinkling under specific conditions an average of 1.38 fruits per tree was protected from sunscald. Per hectare sprinkling on these three days yielded around € 621 per ha. (Assuming: 3000 trees/ha, 6 fruits/kg, price € 1.10 or € 0.20 for industrial use). * Rot resistance test: The Louis Bolk Instituut is attempting to develop a test for the evaluation of the natural resistance of the fruit. This demonstrates, for example that apples with a high nitrogen content have more and larger areas of rot than apples with a lower nitrogen content. * Prospects offered by calcium chloride (CaCl2 ) before or after harvest: A pilot experiment was carried out on a farm to look into the prospects of spraying with CaCl2 before the harvest or rinsing with CaCl2 after harvest to reduce fruit rot. Neither treatment led to a reduction in fruit rot, but rather to an increase. * International association for ‘Organic Food, Quality and Health’ (FQH): The purpose of the group of researchers and traders brought together under the FQH banner is to develop a new concept of quality based on life processes and to select and further develop relevant methods of measurement

Annual report 2003 LBI organic fruit growing research: including plans for 2004

Our objectives in soil management research combine a number of issues: soil fertility, production, fruit quality, growth regulation, prevention of night frost damage, leaf decomposition (scab) and practical feasibility. This will result in different regimes of weed control, fertilisation, foliar feeding and watering for each plot. The evaluation criteria remain particularly difficult to assess. The proposed revised edition of the soil book (LF39) is combined with the final publication of the regulation project which appeared in de winter of 2003 as a hand-book “Biologische Appels en Peren – teeltmaatregelen voor kwaliteitsfruit-” (Organic apples and pears – cultivation measures for quality fruit) (LF75, ed. Joke Bloksma). Time after time our research shows that good crop regulation is the basis for a quality crop. This applies to all varieties, but Elstar requires special attention because of its susceptibility to biennialism. This last year lime sulphur was available for controlling scab. This enabled us to benefit from the side effects of blossom thinning. Trials are still being run internationally on new thinning agents for organic growing. To date however there is no prospect of a more efficacious agent than lime sulphur without the undesirable side effects. This begs the question of how much more energy should be spent on this research. We take the view that there are other areas to be developed which are essential to good crop regulation. There is scope for further development of an adapted pruning method which very specifically anticipates the prospects for the coming year. Pruning also seems to be important for the new variety Topaz, while we still need to ensure that we get sufficient fruit on the tree. Many trials in which we monitor flowering and bearing rates show time and again that Elstar trees with slightly excessive growth levels have much poorer flowering rates in the following year, even where there is no excessive vigour. Thus much attention still needs to be paid to growth regulation. LaMi is running a project in Utrecht province in which demonstration trials are being carried out to encourage the use of calcium hydroxide in conventional fruit growing. As advisor the LBI contributed its experience from the projects in previous years. Infection of a fruit by fungi or disease depends among other things on the resistance of the fruit. The resistance of a product to fungi, pests and diseases is a parameter for the quality of the product. The Louis Bolk Institute is attempting to develop a test for the evaluation of the natural resistance of the fruit, in which the apple can demonstrate how well or poorly a fruit rot fungus (Botrytis c.) can spread in the flesh of the fruit. The LBI has previous experience with self-disintegration tests. The problems here were the replicability and the unknown sources of infection. Fruit quality is an increasingly important aspect of fruit production. The supermarkets in particular continually raise the standards required for (external) product quality. Using organic growing methods it may not always be possible to meet the high standards for external quality. This means that the internal quality will become increasingly important. LBI is currently running 2 projects on apple quality: “Classy Apples in the Chain” (2001-2004) which involves monitoring and working with partners in the chain to reduce the quality gap between supply and demand and also reduce the distance between the start and end of the chain. The second project, “Parameters for Fruit Quality” (2001-2003) addresses more fundamental issues about suitable quality parameters for organic production. (See also 2002 report)

Beter boeren met biodiversiteit in Drenthe

Eindverslag van het demonstratie project Beter boeren met biodiversiteit in Drenthe (2010-2013). Met 21 Drentse akkerbouwers is gewerkt aan verduurzaming van het bodembeheer op eigen bedrijf. Projectactiviteiten waren gericht op denken (studiebijeenkomsten, kennisuitwisseling) en doen (zelf aan de slag). In Zuidwolde en in 1e Exloermond zijn metingen verricht in demo's. Via nieuwsbrieven en vakbladen is breed gecommuniceerd

Parameters for apple quality - 2 - and the development of the ‘inner quality concept’ 2001-2003

We found clear correlations between management measures, tree characteristics and fruit characteristics. This means that growers can regulate apple quality during the growing season. On the basis of the two apple experiments, we can distinguish respective sets of growth and differentiation parameters and evaluate them in the light of conventional fruit cultivation science. Our results have little new value for fruit growing in practice, however. The value of our research lies in the approach developed to draw up a quality concept and the way in which we can apply this concept to crops about which little knowledge exists regarding the relationship between management measures, crop characteristics and product quality characteristics. Our research also offers a method to validate experimental parameters

Classy Apple project' to reduce the quality gab between suppley and demand of organic apples

LBI has started a project (2001-2003) to explore and reduce the bottlenecks and obstacles to fruit quality in the various market sectors by working with fruit growers, traders, extension services and research institutes together

Bodemvruchtbaarheid behouden: bijdragen van boer tot burger

De bodemstructuur in Flevoland verslechtert, net als in andere delen van het land. Dat komt omdat de boer steeds meer in een spanningsveld staat tussen korte- en langetermijnbelangen, waarbij steeds vaker voor de korte termijn wordt gekozen, ten koste van de lange termijn bodemvruchtbaarheid. Deze brochure reikt de akkerbouwer mogelijkheden aan voor verbetering. Bovendien wordt inzicht gegeven in de mogelijkheden die ketenpartijen, consument en samenleving hiervoor hebben. De bodem is immers niet alleen natuurlijk kapitaal van de boer, maar ook common good van de samenleving en toekomstige generaties

Informatie en literatuur voor de biologische fruitteelt : Information and literature for organic fruit growing

Informatie over organisaties voor de biologische fruitteelt in diverse landen. Verwijzingen naar onderzoek

Investeren tot in de bodem: Evaluatie van het proefveld Mest Als Kans

Doel van het project Investeren tot in de Bodem was het verkrijgen van inzicht in het meerjarige effect van veelgebruikte organische meststoffen en bodemverbeteraars op bodemvruchtbaarheid en nutriëntenemissie. In november 2006 zijn daarom in acht van de dertien bemestingsvarianten van het sinds 1999 bestaande proefveld Mest als Kans metingen gedaan aan de fysische, chemische en biologische bodemeigenschappen en is de invloed van bemestingsstrategieën op opbrengst en productkwaliteit bepaald. De proef is opgenomen in de vruchtwisseling van een groententeeltbedrijf op lichte zavelgrond bij Lelystad. De bemesting vond plaats in mei. Op basis van een stikstofgift van 100 kg werkzame N/ha, een maximale fosfaatgift van 80 kg P2O5 per ha per jaar en voor GFT- en groencompost een wettelijk toegestane hoeveelheid droge stof van 6000 kg per hectare per jaar. Op basis van een zestal belangrijke criteria voor ondernemers en maatschappij lijken de varianten GFT+drijfmest, potstalmest en natuurcompost in de hier beschreven proefopzet de beste investering in de bodem met de minst negatieve gevolgen voor het milieu

Bijzondere Bemesting: Kansrijke strategieën voor duurzaam bodemmanagement

Om die transitie naar duurzaam bodemmanagement te ondersteunen heeft het Louis olk Instituut binnen het project Bijzondere Bemesting onderzoek uitgevoerd dat antwoord moest geven op de volgende vragen: • Wat zijn de effecten van mest en compost op bodem en gewaskwaliteit en wat zijn de mogelijkheden voor de inzet van niet dierlijke meststoffen? • Hoe kan bij een bemesting gericht op fosfaatevenwicht de beschikbaarheid van stikstof en fosfaat gewaarborgd blijven? • Waarom zijn bepaalde bedrijfsstrategieën succesvol

Nitrogen efficiency in organic farming using a GPS precision farming technique

In the coming years, agriculture in the Netherlands will be forced to produce more high quality produce with smaller inputs of fertilisers. Organic agriculture should play a leading role and set an example for sustainable soil management. This implies greater nutrient use efficiency and fewer inputs. GPS-controlled precision tillage using the same tracks in the field year after year offers the opportunity to improve soil structure. The tracks become compacted, improving trafficability (Vermeulen & Klooster, 1992). Our hypothesis is that the soil structure of the remaining beds will improve, providing better aeration and rooting for the crop and access to necessary nutrients. This would mean that nutrient use efficiency would improve in GPS-controlled precision tillage systems. The aim of this study was to assess the effects of a GPS-controlled precision tillage system using permanent tracks on soil structure, nutrient use efficiency and spinach yield. The study was carried out at an organically-managed arable farm in the Netherlands