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Commercial narcissus production in Turkey is mostly carried out in Izmir, Mersin, Adana and Samsun provinces and predominantly favours the multi-headed tazetta cultivars. On the other hand, the Netherlands and Great Britain, as the leading narcissus producing countries, especially breed and export a wide range of trumpet, large-cut, small-cup and double cultivars which demonstrate full adaptation to colder climates. In this research, realised in an open field belonging to Ege University’s Bayindir Vocational Training School, cool climate narcissus cultivars were examined in terms of their floral quality in Mediterranean ecological conditions. For this purpose, 22 different Narcissus cultivars were scrutinized through a set of visual criteria for their sprouting and flowering time, flowering duration, stem height and width together with the amount and diameter of their flowers. The cultivars demonstrated rather different outcomes. Thus their 20% sprouting times were between 16 and 37 days from planting (with ‘Precocious’ and ‘Cheerfulness’ being the extremes); the 20% flowering times were within 70 and 94 days from planting (‘Tête-à-Tête’ and ‘Strong Gold’ being the earliest and ‘Precocious’ the latest) and flowering duration was between 16 and 38 days (‘Actaea’ and ‘Salome’). In addition, stem lengths varied between 19.6 cm (‘Tête-à-Tête’) and 48.5 cm (‘Golden Harvest’) and stem diameters were between 0.55 cm (‘Tête-à-Tête’) and 1.48 cm (‘Carlton’). The largest flower diameter occurred on ‘Sempre Avanti’ (12.1 cm) and the highest number of flowers per stem were found on ‘Tête-à-Tête’ and ‘Cheerfulness’. Therefore, this research showed that most cool climate narcissus cultivars can adapt successfully to Mediterranean ecological conditions suggesting that the cultivars used in landscape projects and the floriculture industries in Turkey could be extended. © 2019 International Society for Horticultural Science. All rights reserved.

WOS: 000558565200013, Flower bulbs are perennial or annual plants with underground structures such as bulb, corn, tuber, and rhizomes. These plants have economic value especially in ornamental plant sector as cut flower, potted flower, and outdoor plants. Most of these plants have garish flower, and many of them are monocotyledon. Cyclamen, Tulipa, Lilium, Narcissus, Gladiolus, Hyacinthus, Crocus, Iris, Allium, Alstroemeria, Anemone, Orchis, Rhododendron, Freesia, Hippeastrum, Muscari, Ornithogalum, Ranunculus, and Zantedeschia are the most important geophytes that are commercially used in the world. These plants can be propagated using conventional and tissue culture techniques. Synthetic seed production is one of these techniques. Synthetic seed, namely, artificial seed, is described as artificially encapsulated plant tissues and somatic embryos with alginate hydrogel. Synthetic seed technology has significant effect on the conservation of the plant tissues and sustainability of the plants. Recently, conservation of the plant species studies significantly increased, and artificial seed method was used as the most common process to conserve important species. in this chapter, oldest and newest synthetic seed production researches were discussed and presented chronologically.

Viral diseases in narcissus can drastically affect yields and quality of narcissus bulbs and flowers, leading even to a total crop loss. To test the frequency of viral infections in production fields in Central Poland, samples were collected over three years from two cultivars and two plantations, and tested for the presence of Arabis mosaic (ArMV), Cucumber mosaic (CMV), Narcissus latent (NLV), Narcissus mosaic (NMV) and the potyvirus group using the Enzyme Linked ImmunoSorbent Assay. Potyviruses, NLV and NMV were detected in almost all leaf samples in both cultivars, in all three years of testing. Other viruses were detected in a limited number of samples. In most cases mixed infections were present. Tests on bulbs have shown the presence of potyviruses and NMV, with the higher number of positives in cultivar ‘Carlton’. In addition, for most viruses an increase in their detectability was observed on both plantations in subsequent seasons.

Nitric oxide (NO) is a molecule that regulates biological processes in plants and may be used in horticultural practice as a potential plant growth regulator. Eucomis autumnalis (Mill.) Chitt., also known as pineapple lily, is a member of the Asparagaceae and native to South Africa. Pineapple lily are well suited for production as pot plants, cut flowers, and garden plants. The potential also exists for this species to be used as a medicinal plant. The aim of the study was to assess the effects of the NO donor of sodium nitroprusside (SNP) on morphological features of E. autumnalis seedlings. The plants grown in a greenhouse were drenched four times, at weekly intervals, with SNP solutions of the following concentration: 0, 100, 200, 300, 400, and 500 μM. The study revealed that the application of SNP significantly improved greenness index of leaves, leaf length, and leaf fresh weight, as compared to the control at all levels. This treatment also showed a significant increase in bulb and root fresh weight, root number, and root length. Application of SNP at 200 μM increased the values of the attributes studied to the maximum extent.

Dit artikel omvat de jaarverslagen van de volgende KNPV-werkgroepen over 2013: Bodempathogenen en bodemmicrobiologie; Fusarium; Oömyceten; Onkruidkunde; Botrytis; Nematoden; Fytobacteriologie; Gewasbescherming en Maatschappelijk Debat; Jongeren.

Onderzoeker Gera van Os begon dit jaar als lector Duurzaam Bodembeheer aan CAH Vilentum in Dronten. "Extra aandacht voor de bodem is een mooie kans." Dit artikel geeft een interview weer met deze onderzoeker.

Cylindrocladium buxicola (syn. C. pseudonaviculatum; teleomorph Calonectria pseudonaviculata) is an important fungal pathogen of Buxus spp. Although widespread in Western Europe, this pathogen has only recently been introduced into North America, where it represents a significant threat to the U.S. and Canadian boxwood industries. Trade of latently infected nursery stock is an important mode of long-distance dissemination and introduction of this pathogen but no methods for detection of latently infected material are available. Also, the pathways for short-distance dispersal of C. buxicola have not been adequately studied. Improved detection methods of this pathogen in air and water samples would benefit future research in this area. We have developed real-time polymerase chain reaction assays for the detection of C. buxicola based on the ribosomal DNA internal transcribed spacer 1 (ITS) and the β-tubulin 2 gene (TUB). Using a TaqMan probe conjugated with a 3′ minor groove binding group (TaqMan MGB probe), the ITS-based assay could reliably detect as little as 10 fg of genomic DNA or 20 copies of cloned target DNA and was approximately 70 times more sensitive than the SYBR Green TUB-based assay. The ITS-based assay provided good but not complete specificity, and is well suited for epidemiological studies. The TUB-based assay, however, proved to be fully specific and can be used for diagnostics. We developed and optimized sample processing and DNA extraction methods for detection of latently present C. buxicola in boxwood plants and quantification of conidia in water and air samples. C. buxicola could be detected in 20 g of plant material, of which only 1 ppm of the tissue was infected, in 10-ml water samples containing as low as 1 conidium/ml, and on Melinex tape pieces representing 12 h of air sampling containing 10 or more conidia. The applicability of the techniques to plant, water, and air samples of practical size was demonstrated.

Een aantal laanboomkwekerijen in Nederland specialiseert zich steeds meer in het kweken van bomen op eigen wortel. Voordeel is dat er nooit onverenigbaarheid kan optreden en er minder of geen sprake is van opslag aan de onderstam. Ook de vraag van afnemers naar bomen op eigen wortel groeit. Wel is het bij stekken belangrijk dat een voldoende fijn vertakt en gelijkmatig wortelstelsel wordt ontwikkeld.

Tulip virus X (TVX) is a Potexvirus causing economic losses in tulip. Potexviruses are generally transmitted by mechanical contact and, indeed, several mechanical transmission pathways for TVX have been identified during tulip bulb production. However, TVX transmission does also seem to occur during bulb storage. Since mechanical transmission is excluded in this period, a biological vector should be involved. The eriophyoid mite Aceria tulipae, the acarid storage mite Tyrophagus putrescentiae, and the acarid bulb mite Rhizoglyphus echinopus are the main arthropod pests of stored tulip bulbs. Therefore, we studied their putative role in transmission of TVX during tulip bulb storage. We show that mites of each of these species can carry TVX with them after feedingon TVX-infected bulbs. In addition, some of the healthy bulbs acquired an infection with TVX when inoculated with mites. Although the current setup of the experiments does not confirm which species of mite transmit TVX, we have strong indications that mites are involved in transmission. Additional research with larger numbers of independent replicates is required to further prove the vector status of each species of mite, the efficiency, and mode of virus transmission. If our results will be confirmed, this would be the first case reporting a Potexvirus to be transmitted by mites, and the first case of anassociation between acarid mites and a plant pathogenic virus. Consequently, TVX control in tulip bulb production should include an adequate control strategy of both eriophyoid and acarid mites.

In the Netherlands, bacterial canker in plum trees (Prunus domestica) is a serious and recent problem in plum production. Bacterial canker, caused by Pseudomonas syringae pv. syringae (Pss) and pv. morsprunorum (Psm), is a serious disease of stone fruit, and occurs in all major stone fruit producing areas of the world. The trunks of the affected plum trees are girdled by bacterial cankers resulting in sudden death of infected trees. Rapid tree death has been observed in several orchards 2-4 years after planting. Disease incidences can be very high, and sometimes complete orchards have to be removed. Recently, plum cultivation in the Netherlands has changed from a relatively extensive into an intensive cultivation. This was made possible by the use of a weak rootstock, Krymsk®1 (VVA-1). The lack of chemicals to fight bacterial diseases in the orchards created a need for alternative methods of disease control. To achieve this, methods such as prevention, biological control and plant resistance must be explored and control strategies to manage plum decline have to be developed. In 2010 a project was started to study the epidemiology and possible control of plum decline

Tulip bulb and flower production greatly contribute to the economy in The Netherlands. However, severe loss in this industry is caused by different viruses. In recent years, diagnostic tools were developed for most of these viruses with Tulip severe mosaic virus (TSMV) as one of the few exceptions. To further characterize TSMV, the virus was amplified by reverse transcription-polymerase chain reaction (RT-PCR) with degenerate primers targeted to conserved sequences of the Heat shock protein 70 gene of viruses from the family Closteroviridae. Phylogenetic analysis of the 0.5 kb HSP70 gene fragments showed that TSMV is closely related to Plum bark necrosis stem pitting-associated virus (PBNSPaV), Apricot stem pitting-associated virus (ASPaV) and Pineapple mealybug wilt-associated virus 1 (PMWaV-1), all three members of the genus Ampellovirus. In addition, a set of primers amplifying a TSMV-specific fragment was designed that enables fast and specific detection of the virus. Additionally to the molecular experiments, two possible modes of virus transmission were tested, viz. by aphids and by soil-borne organisms. However, no transmission was recorded by both methods.

Dieback of red currant (Ribes rubrum) and gooseberry (Ribes uva-crispa) is an increasing problem in commercial fields in the Netherlands. Field surveys were done in 2006–2007 and samples with dieback symptoms were analysed. In this study the causal agent was diagnosed as Eutypa lata, based on morphological characteristics and rDNA-ITS sequence data. The field surveys revealed the presence of the anamorph and teleomorph states of the fungus produced on dead infected currant wood. Eutypa lata is a vascular pathogen of many woody plants. Related fungi from the same family Diatrypaceae are difficult to distinguish from E. lata based on morphological features. The genetic variability of E. lata was compared by rDNA-ITS sequencing of isolates from different hosts and origins. Within the E. lata isolates little variability in the ITS sequences was observed. Phylogenetic analysis showed no clear subdivisions within the species. Eutypa lata strains isolated from the different hosts were closely related, indicating that there is no direct evidence for host specificity.

Verslagen van de KNPV-werkgroepen: Bodempathogenen en bodemmicrobiologie, Phytophthora en Pythium, Onkruidkunde, Botrytis, Nematoden, Graanziekten, en Fytobacteriologie.

Aan het begin van het FES-project ‘Versterking infrastructuur plantgezondheid' zijn de belangrijkste knelpunten op plantenvirologisch gebied in Nederland geïnventariseerd. Criteria hierbij waren vooral fytosanitaire status, economisch belang en de behoefte aan betrouwbare detectie- en identificatiemethoden. Op basis hiervan is een prioriteitenlijst opgesteld van de (gereguleerde) virussen uit de volgende virusgroepen: Potyvirussen, Nepovirussen, Tospovirussen en Potexvirussen. Daarnaast werd zo’n lijst opgesteld voor viroïden en fytoplasma’s. Aan de prioriteitenlijst werden toegevoegd: Pospiviroïden en Fytoplasma’s. De verkregen gegevens werden opgenomen in de Q-bank.

Seed survival of Striga hermonthica is influenced by amendments of organic matter; however, the role of organic matter quality (C:N ratio) and mechanisms for enhanced seed decay are inadequately understood. In a field experiment, plots received a single dose of 6 t organic matter per hectare but with large differences in quality in terms of C:N ratio. Soil moisture, soil temperature and soil ethylene concentrations were measured, while buried nylon seed bags were periodically withdrawn from the soil and assayed for seed viability and germination. Organic matter amendments incorporated in the soil significantly depressed S. hermonthica seed survival. The effect was strongest with organic matter of high quality. Organic matter of low-quality enhanced soil water content during the first five days after a rainfall event and resulted in a 0.5 °C lower soil temperature. The highest observed ethylene concentrations in the soil were between 2 and 3 ppm, high enough to stimulate S. hermonthica seed germination. Maximal seed germination in vitro was obtained after 48 h of exposure to 1 ppm ethylene. However, observed changes in seed germination and viability of retrieved seed batches (seed survival) did not correlate with soil ethylene concentrations. The latter in turn did not differ between qualities of the applied organic matter. Seed survival decreased with increasing time of burial, especially after 4–8 weeks. As S. hermonthica attachment mainly occurs during the first four weeks of the cropping season the observed effect of seed decay may hardly be beneficial for the on-going cropping season. Nutrient release through decomposition of organic matter, enhancing decay of S. hermonthica seeds, is proposed as the probable cause of seed depletion in the soil.

De schade door agressief snot was in de afgelopen 10 jaar zeer groot. Naast verlies aan bollen en extra werk door uitzoeken heeft het imago van de hyacint een flinke deuk opgelopen en staat de afzet onder druk. Afgelopen jaren is vanuit onderzoek en praktijkervaringen van telers en exporteurs veel bekend geworden over agressief snot. Met deze kennis is de schade als gevolg van het agressief snot beperkt te houden. Een teelt helemaal zonder agressief snot zal waarschijnlijk onmogelijk zijn. Echter door veel inspanning van telers in de komende jaren weer hyacinten geteeld gaan worden die nog slechts een geringe kans lopen om massaal leeg te lopen. Daarnaast moet het witsnot niet vergeten worden.

In het Nederlandse oppervlaktewater zijn de fosfaatconcentraties vaak te hoog en vormt eutrofiëring een groot probleem. Fosfaatuitspoeling uit landbouwgronden draagt flink bij aan de totale fosfaatbelasting van het oppervlaktewater. Met brongerichte maatregelen, zoals evenwichtsbemesting, zal in sommige delen van het landelijk gebied de hoofddoelstelling van de Kaderrichtlijn Water niet worden gerealiseerd. Hiervoor zijn aanvullende maatregelen nodig, die kunnen bijdragen aan het verbeteren van de chemische waterkwaliteit. We hebben de effectiviteit getest van een drainagebuis omhuld met ijzerzand om fosfaatuitspoeling te verminderen. Deze veldproef is uitgevoerd op een duinzandgrond in het bloembollengebied. Het gemiddelde zuiveringsrendement van de omhulde drainagebuis bedraagt 94 procent. Het omhullen van drainagebuizen met ijzerzand lijkt een veelbelovende maatregel voor het verminderen van fosfaatuitspoeling

The Rx1 protein, as many resistance proteins of the nucleotide binding–leucine-rich repeat (NB-LRR) class, is predicted to be cytoplasmic because it lacks discernable nuclear targeting signals. Here, we demonstrate that Rx1, which confers extreme resistance to Potato virus X, is located both in the nucleus and cytoplasm. Manipulating the nucleocytoplasmic distribution of Rx1 or its elicitor revealed that Rx1 is activated in the cytoplasm and cannot be activated in the nucleus. The coiled coil (CC) domain was found to be required for accumulation of Rx1 in the nucleus, whereas the LRR domain promoted the localization in the cytoplasm. Analyses of structural subdomains of the CC domain revealed no autonomous signals responsible for active nuclear import. Fluorescence recovery after photobleaching and nuclear fractionation indicated that the CC domain binds transiently to large complexes in the nucleus. Disruption of the Rx1 resistance function and protein conformation by mutating the ATP binding phosphate binding loop in the NB domain, or by silencing the cochaperone SGT1, impaired the accumulation of Rx1 protein in the nucleus, while Rx1 versions lacking the LRR domain were not affected in this respect. Our results support a model in which interdomain interactions and folding states determine the nucleocytoplasmic distribution of Rx1.

In bloembolgewassen kan de schimmel Botrytis veel schade veroorzaken. Botrytis kan snel toeslaan. Snelle en gevoelige toetsen kunnen dan bijdragen tot het op tijd nemen van maatregelen om ‘vuur’ te beheersen. Er komen verschillende Botrytis-soorten voor, die moleculair- genetisch gedetecteerd en geïdentificeerd kunnen worden. Serologische toetsen bleken niet te werken. PCR-methodieken, gebaseerd op enkele kleine verschillen in DNA-sequenties wel. Mogelijk kunnen via monitoring van luchtmonsters waarschuwingssystemen voor vuur verder worden verbeterd.

Het gebruikswaarde-onderzoek tulp nieuwe stijl is in 1996 gestart door de Koninklijke Algemeene Vereeniging voor Bloembollencultuur (KAVB). Een commissie bestaande uit onder andere telers, handelaren en veredelaars begeleidt dit onderzoek, dat bestaat uit teeltonderzoek op twee locaties (zand- en kleigrond), broeierijonderzoek en houdbaarheidsonderzoek. Doel van het gebruikswaarde-onderzoek is het in kaart brengen van teelt- en broei-eigenschappen en houdbaarheid van nieuwe(re) tulpencultivars. Dit verslag behandelt de resultaten van de twaalfde serie cultivars die in het onderzoek is opgenomen.

De land- en tuinbouw ontwikkelen zich richting intensievere en complexere bedrijfssystemen. Binnen dergelijke bedrijfssystemen wordt een nog groter beroep gedaan op de bodemgezondheid. Alle keuzes die de teler maakt, moeten gericht zijn op zo min mogelijke schade door verschillende bodempathogenen, zoals aaltjes, schimmels en bactereriën. Dit moet bovendien binnen zeer strenge eisen met betrekking tot inzet van gewasbeschermingmiddelen en bemesting. Deze trend vergt nieuwe kennis over inpasbaarheid en bedrijfszekerheid van teeltmaatregelen om de bodemgezondheid optimaal te gebruiken. In 2006 is in opdracht van LNV het project: 'Bodemgezondheid binnen bedrijfssystemen' gestart. Dit project richt zich op de ontwikkeling van een pakket aan maatregelen om de bodemgezondheid te verbeteren. In dit artikel worden de opzet en de eerste resultaten beschreven.

De notitie ‘Kennis- en innovatiesystemen in de Greenportregio’s: monitor IDC Duin- en Bollenstreek 2014’ is een publicatie van onderzoeksthema Methodieken Kennisoverdracht (MK). Het betreft een aanvulling van de stand van zaken (2014) op de paragraaf greenportregio Duin- en Bollenstreek (pp. 40-43) in de gelijknamige tweede tussenrapportage resultaten monitorstudie 2013 (http://edepot.wur.nl/297588).

De overheid stelt steeds nieuwe beperkingen aan middelen en meststoffen. Volgens de nieuwe Lector Duurzaam Bodembeheer Gera van Os gaan de ontwikkelingen daarom gedwongen van chemisch naar evenwichtiger. Moderne technieken en analysemethodes kunnen daarbij van dienst zijn. „Teelt moet optimaal in duurzaamheid.”

Bij de ontwikkeling van de eerste versies van meerlagenteelt in twee tot drie lagen in een schuurkas, richtte het onderzoek zich vooral op de minimum lichtbehoefte van tulp. Bij de ontwikkeling van meerlagenteelt 2.0 met zes of meer lagen in een cel, moet het onderzoek zich richten op de minimum verdampingsbehoefte. Hoe lager de totale verdampingsbehoefte tijdens de trek, hoe energie-effieciënter de broei wordt en groter de mogelijkheden tulpenbroei klimaatneutraal te houden.

Berekeningen laten zien dat er een economische perspectief is voor waterbroei van snijhyacint. Teelttechnisch zijn er nog steeds vragen.

Onderzoeker Gera van Os begon dit jaar als lector Duurzaam Bodembeheer aan CAH Vilentum in Dronten. "Extra aandacht voor de bodem is een mooie kans." Dit artikel geeft een interview weer met deze onderzoeker.

Herkomst, detectie en mogelijke bestrijding van bacterieziekten is onderzocht door PPO en PRI. Het project, gefinancierd door het voormalige Produktschap Tuinbouw, leverde meer inzicht op over de grote groep bacteriën die ook in veel siergewassen voor behoorlijke schade kunnen zorgen.

Vanaf 2011 heeft het Praktijkonderzoek Plant & Omgeving (PPO) sector Fruit te Randwijk het rassenonderzoek met zwarte bessen gedurende vier jaren voortgezet. Het doel is (nieuwe) rassen te zoeken en te toetsen onder Nederlandse (Zeeuwse) teeltomstandigheden, die een verbetering kunnen zijn van de huidige rassen voor wat betreft de productiviteit, de beskwaliteit en de gevoeligheid voor ziekten en plagen. Dit rapport is het eindverslag van het project dat eind 2014 is afgelopen.