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Genetic resources and selected conservation methods of tomato
Get PDFTomato is one of the most popular vegetable crops. However, over time, the species has suffered a strong genetic diversity reduction and domestication bottlenecking. This growing trend is known as the genetic erosion. The human intervention on the genetic erosion intensification is high and has severe implications on the future programmes of management and use of S. lycopersicum biodiversity. The wild tomato species (especially accessions originating from the Andes to Mesoamerica) harbour many valuable genes, which have been lost among the cultivated ones. Therefore, there is an increasing interest to mine new alleles from the interspecific gene pool of Lycopersicon section. Sustainable genetic diversity management constitutes a basis for crop improvement, classification and protection. Moreover, conservation of plant genetic resources is crucial to food security, as well as pharmaceutical industry. There are a few strategies developed which address the preservation of tomato genetic resources. In situ and ex situ conservation are the two main complementary methods of biodiversity protection. The aim of this review is to summarise the most recent information about tomato genetic resources, genetic erosion phenomenon, as well as some traditional and modern preservation strategies
Development of effective non-chemical methods for controlling black-grass (Alopecurus myosuroides Huds.)
Get PDFIn einem 7-jährigen Großflächenversuch wurde an zwei Standorten (Marsch bzw. Parabraunerde) im Rahmen einer Fruchtfolge mit Winter-Raps, 3 x Winterweizen und in den letzten Jahren Sommergetreide untersucht, mit welchen Bodenbearbeitungsverfahren (Pflug, Grubber, flache Mulchsaat) sich der Acker-Fuchsschwanz (AF) am besten niederhalten lässt, welche Effekte eine spätere Saatzeit speziell beim Anbau von Winterweizen auf den AF hat und was durch die Fruchtfolgeglieder „Winterraps“ bzw. „Sommergetreide“ bei der AFBekämpfung erreicht werden kann. Chemisch wurde die AF-Bekämpfung im Winterweizen mit mehreren Herbizidvarianten durchgeführt: Bodenherbizide zum VA/NAK-Termin, gefolgt von Atlantis im zeitigen Frühjahr. Auf Teilstücken wurden nur Bodenherbizide nach der Saat appliziert, durch den Verzicht auf Atlantis hier wurde eine voll ausgeprägte Resistenz des Acker-Fuchsschwanzes gegenüber diesem Herbizid simuliert, die de facto auf den Flächen derzeit noch nicht vorhanden war. Man wollte sehen, was passiert, wenn Atlantis u.a. ALS-Hemmer resistenzbedingt nicht mehr eingesetzt werden können. Im Raps und Sommergetreide erfolgte keine Differenzierung, sondern eine einheitliche Herbizidbehandlung, da ACCase-Hemmer zunehmend nicht mehr wirkten und daher wenig Spielraum verblieb. Der AF wurde in Abhängigkeit von den Acker-Fuchsschwanzauflauf-Wellen im Mittel 10-mal pro Jahr gezählt. In 2012 und 2016 wurden außerdem vor dem AF-Samenausfall im Sommer Bodenproben aus drei Tiefen gezogen und im Gewächshaus der Besatz von keimfähigen AF-Samen im Boden anhand aufgelaufener Pflanzen erfasst.Die wichtigsten Ergebnisse: Solange Atlantis eingesetzt wurde und wirkte, blieben alle ackerbaulichen Effekte unsichtbar. Ohne Atlantis stieg in den Mulchsaaten im dreijährigen Winterweizenanbau der AF-Besatz stark an. Der Pflug hielt den AF in den Kulturen nieder. Die späte Aussaat von Winterweizen reduzierte den AF-Besatz. Mit Winterraps konnte der AF-Besatz niedergehalten werden, solange die dort applizierten blattaktiven Herbizide (DIMs) wirkten. War das nicht mehr der Fall, war der AF beim Anbau von Winterraps nur mit Bodenherbiziden nicht ausreichend zu kontrollieren. Mit Sommergetreide ließ sich der AF-Besatz niederhalten, wenn die Grundbodenbearbeitung und Saatbettbereitung im Herbst erfolgte, im Frühjahr Glyphosat appliziert und danach die Sommergetreidesaat mit möglichst wenig Bodenbewegung eingeschlitzt wurde. Durch einen dreijährigen Sommergetreideanbau konnten so der oberirdische AF-Besatz und auch der Besatz mit AF-Samen im Boden wieder reduziert und die in 2010-12 stark mit AF befallenen Teilflächen weitgehend saniert werden.In a seven-year long-term field experiment at two locations in Northern Germany (marshland and loamy soil, respectively), field trials were carried out within a crop rotation of winter oil seed rape, 3 x winter wheat and spring crops (cereals) during the last years. The aim was to find out which method of soil cultivation (ploughing, chisel plough, reduced tillage with power harrow) achieved the highest efficacy in controlling black-grass under field conditions. Furthermore, different drilling dates of winter wheat, the cultivation of winter oilseed rape and of spring cereals were tested with regard to their level of black-grass control.In winter wheat, different herbicides were applied with the aim of black-grass control: Pre-emergence herbicides (flufenacet), followed by Atlantis (mesosulfurone) in March/April. On several experimental plots only pre-emergence herbicides were used. The reason: a fully developed resistance of black-grass against Atlantis should be simulated in order to see, what happened, when Atlantis was no longer applicable. Still now this resistance was not fact on the locations. Winter oilseed rape and spring cereal plots were treated with herbicides uniformly because of existing herbicide resistances of black-grass against ACCase-Inhibitors. So there were no more possibilities of differentiation. Black-grass plants/ears in the plots on both locations were counted about 10 times per year dependant on the emergence of black-grass.In summer 2012 and 2016, soil samples from three different soil depths were taken before black-grass seed dispersal. In a greenhouse, soil samples were put into dishes, stirred in order to stimulate the germination of black-grass seeds by light and kept humid. All emerging black-grass seedlings were counted and then removed. This was repeated until no more black-grass plants emerged.Results: When the herbicide Atlantis was applied and showed high efficacy, no effect of different tillage systems on black-grass populations was visible. Without Atlantis application, the level of black-grass exploded within three years of winter wheat production in plots where chisel plough or reduced tillage systems were utilised. Ploughing kept the level of black-grass low and late drilling dates of winter wheat reduced the level of black-grass infestation. A low level of black-grass in winter oilseed rape was only observed as long as ACCase inhibiting herbicides (DIMs) achieved a high efficacy. Otherwise, the control of black-grass in winter rape was not sufficient. Three years of spring cereals cultivation reduced the level of black-grass infestation within the crop as well as seed densities in the soil. Important: ploughing and making of the seedbed should be done in autumn. In spring: glyphosate-application before sowing and sowing spring crops with as little soil motion as possible
Resistance of herbicides against Apera spica-venti in Lower Saxony
Get PDFHerbizidresistenzen lassen ganze Wirkstoffgruppen weltweit wegfallen. In Deutschland zeigt sich dieses Phänomen auch auf niedersächsischen Flächen, die seit Jahren intensiv in engen Getreidefruchtfolgen bewirtschaftet werden. Neben den Wirkstoffgruppen der ALS-Hemmer und Photosynthesehemmer sind beginnend auch die ACCase-Hemmer resistenzgefährdet. Diese Entwicklung hat sich bei Apera spica-venti durch einseitigen Herbizideinsatz und enge Getreidefruchtfolgen aufgebaut. In den Jahren 2009 bis 2016 wurden auf 269 Monitoringflächen Samenproben von Apera spica-venti gezogen und in Biotestungen die Wirksamkeit von Herbiziden unterschiedlicher Wirkstoffklassen getestet. Die Resistenz bei Apera spica-venti gegenüber Herbiziden der HARC-Gruppe B ist in Niedersachsen weit verbreitet. Auf den ersten Flächen haben sich bereits multiple Resistenzen gegen die HRAC-Gruppen A und B entwickelt.Worldwide whole groups of active substances are getting ineffective due to herbicide resistance. This phenomenon was observed on numerous fields in Lower Saxony, Germany, which have been intensively cultivated in narrow crop rotations for years. Besides the ALS inhibitors and the photosynthesis inhibitors, also ACCase inhibitors are at risk of becoming resistant. This development was established in Apera spica-venti by the one-sided use of herbicides and the narrow crop rotations. From 2009 until 2016 seed samples of Apera spica-venti were grown on 269 monitoring areas and the efficacy of herbicides from different classes of active substances was tested in bioassays. The resistance of Apera spica-venti to herbicides of the HRAC group B is widespread in Lower Saxony. Multiple resistances to the HRAC groups A and B have already developed on the first areas
Validation of yellow nutsedge (Cyperus esculentus) control strategies in maize in an on-farm, large-scale field trial
Get PDFEs wurde ein Großparzellenversuch von 2013 bis 2015 durchgeführt, um die Wirkung von Maisanbau während mehrerer Jahre auf den Cyperus esculentus Befall in einem Feld zu untersuchen. Dabei wurden Bekämpfungsstrategien, die zuvor in Kleinparzellenversuchen entwickelt und geprüft worden waren, validiert. Der Versuch beinhaltete vier Bekämpfungsverfahren. Jedes Frühjahr wurden Bodenproben gezogen, im Gewächshaus ausgelegt und angetrieben. Anschließend wurde die Anzahl der sich entwickelnden Erdmandelgrastriebe gezählt.Der Ausgangsbesatz war heterogen verteilt. Zudem standen einzelne Feldbereiche aufgrund starker Regenfälle mehrmals unter Wasser. Trotz der Variabilität und der schwierigen Wetterbedingungen konnten folgende Schlussfolgerungen gezogen werden: Maisanbau kombiniert mit intensiver Bekämpfung (2-4 Bekämpfungsmaßnahmen) über mehrere Jahre ermöglichte eine Reduktion der Cyperus esculentus-Dichte um rund 80 %. Es zeigte sich, dass Hacken, die Wirkstoffe S-Metolachlor, Mesotrione, Terbuthylazin, Rimsulfuron und Bentazon sowie das Kombinationsprodukt mit den Wirkstoffen Foramsulfuron, Thiencarbazone und Iodosulfuron wichtige Komponenten einer Cyperus esculentus-Bekämpfungsstrategie in Mais sind.Maisanbau mit einer intensiven Unkrautbekämpfung ist ein wirksamer Ansatz, um C. esculentus unter Kontrolle zu halten und den Besatz zu reduzieren. Aufgrund der intensiven Bekämpfung können Ertragsdepressionen jedoch nicht ausgeschlossen werden. Landwirte in der betroffenen Region setzen diese Bekämpfungsansätze bereits um.A large on-farm field trial was carried out between 2013 and 2015 to investigate the effect of repetitive maize cropping on Cyperus esculentus infestation over time. Intensive control strategies, developed and investigated in small-scale trials, were validated. Four C. esculentus treatment strategies were installed. Soil samples were taken each year put in the greenhouse and the number of C. esculentus sprouts was assessed.Initial infestation was patchy. Field areas were flooded several times due to heavy rainfall. Despite the inherent variability and the adverse weather conditions following conclusions can be drawn: Growing maize combined with intensive weed control (2-4 passes), reduced infestation on average by 80%. Principal components for Cyperus esculentus control strategies are hoeing, the active substances S-metolachlor, mesotrione, terbuthylazine, rimsulfuron, bentazone, and a herbicide containing foramsulfuron, thiencarbazone and iodosulfuron.Growing maize combined with high intensity weed control is an effective approach to manage and reduce C. esculentus infestation. Yield depressions due to this highly intensive weed control cannot be rule out. Nevertheless, farmers in the affected region have adopted these approaches
Site-specific weed control by direct injection - an innovation for precision spraying in crop production
Get PDFOft werden in der Landwirtschaft Tankmischungen mit mehreren Pflanzenschutzmitteln (PSM) eingesetzt, wodurch eine teilflächenspezifische Applikation einzelner PSM unmöglich wird. Bei Direkteinspeisesystemen ist dagegen ein teilflächenspezifischer Einsatz möglich, da PSM und Wasser aus getrennten Behältern in Echtzeit dosiert und erst kurz vor der Anwendung vermischt werden, ohne Restmengen zu verursachen. Die technische Umsetzung in praxistaugliche Geräte, welche allen Anforderungen an Dosierung, Reaktionszeit und Reinigung/Restmengen gerecht werden, soll mit einem Feldspritzgerät mit Direkteinspeisung erfüllt werden. Hierzu wurde ein Feldspritzgerät mit Direkteinspeisung entwickelt und in Praxistests eingesetzt. Ziel der Versuche war die Zuverlässigkeit des Systems und die Auswirkungen der ortsspezifischen Applikation unter Feldbedingungen zu bewerten. Hierfür wurde das System intensiv geprüft, wobei die Optimierung der Handhabung und der Elektronik sowie die Erprobung im praktischen Betrieb eine hohe Bedeutung hatten. Die Ergebnisse zeigen, dass ein praxisgerechtes System zur verzögerungsfreien Direkteinspeisung realisiert werden kann und eine teilflächenspezifische Anwendung verschiedener Pflanzenschutzmittel möglich ist.In agriculture tank mixes with several pesticides are often used, where it is impossible to apply individual pesticides to specific areas. However, direct injection systems can be used for the specific use of individual pesticides on a sub-area basis, since they dose pesticides and water from separate containers in real time and mix them before application without causing residues. The technical conversion into practical equipment, which meets all requirements for dosage, reaction time and cleaning/residual quantities, is to be fulfilled with a fieldsprayer prototype with direct injection. In the practical tests a fieldsprayer with direct injection was developed and used. The aim of the project was to carry out an intensive examination of the direct injection under field conditions to assess the reliability of the system and the effects of the site-specific application. An important question in this context is the optimization of handling and electronics as well as the application in practical operation. The results show that a practical system for instantaneous direct injection could be implemented and that it is possible to use different crop protection agents for specific areas
Trials to combat seed building catch crops as weeds in following sugar beets
Get PDFEine wachsende Beliebtheit des Zwischenfruchtanbaus im Rahmen des Greenings, sowie zunehmend milde Winter haben dazu geführt, dass Praktiker sich bisweilen auch mit aussamenden Zwischenfrüchten in der nachfolgenden Sommerung beschäftigen müssen. Die Wirkungsspektren bisher erfolgreich eingesetzter Herbizide geben meist keine Auskunft über eine Wirkung gegen beispielsweise Malve, Senf und Wicke. Zu dieser Fragestellung wurde 2016 an der FH Südwestfalen in Soest ein Halbfreiland-Gefäßversuch mit 10 verschiedenen Zwischenfrüchten (Buchweizen, Phacelia, Ölrettich, Alexandrinerklee, Sommerwicke, Kulturmalve, Öllein, Rauhafer, Gelbsenf, Ramtillkraut) angelegt. Die Zwischenfrüchte wurden kulturrein ausgesät und in frühen Entwicklungsstadien jeweils einmalig mit den Zuckerrübenherbiziden Gotix Titan und Belvedere Extra sowie einer praxisüblichen Kombination beider Produkte behandelt. Diese Kombination erzielte bei Buchweizen, Phacelia, Alexandrinerklee, Öllein und Ramtillkraut hohe Wirkungsgrade. In 2017 wurde dieser Ansatz auf einen Feldversuch übertragen, der nun die Konkurrenzkraft der Kulturpflanze Zuckerrübe berücksichtigte und mit mehrmaliger praxisüblicher Behandlung in NAK 1-3 stattfand. Dazu wurde eine Mischung der als problematisch identifizierten Kulturen Buchweizen, Phacelia und Gelbsenf kurz vor bzw. zeitgleich mit den Zuckerrüben ausgesät. Diese wurden mit den gleichen Herbizidvarianten wie 2016 behandelt. Goltix Titan und Belvedere Extra in Mischung war auch hier die beste Variante mit hohem Wirkungsgrad auf alle drei Zwischenfrüchte. Belvedere Extra zeigt eine ähnlich gute und ausreichende Wirkung.The growing popularity of catch crops in the scope of greening and increasing milder winters can lead to problems with self-seeding catch crops in following summer crops. The effective ranges of so far successfully applied herbicides usually do not provide information on the efficacy against e.g. mallow, yellow mustard and common vetch.To answer this question a pot trial with 10 catch crops (buckwheat, (tansy) phacelia, oil radish, berseem clover, common vetch, common mallow, linseed, black oat, yellow mustard and niger thistle) was carried out under semi field conditions at the University of Applied Science in Soest / Germany in 2016. The catch crops were cultivated separately and treated once in early growth stages with the sugarbeet herbicides Goltix Titan and Belvedere Extra as well as a customary combination of both products. The combination achieved high efficacy against buckwheat, phacelia, berseem clover, linseed and niger thistle. In 2016 this approach was transferred to a field trial, where the competitive ability of sugarbeet was factored in and treatments were customarily applied three times according to the cotyledons stages (NAK 1-3). Three catch crops that were identified as problematic were sown shortly before or with the sugarbeets. The treatments were the same as in 2016. The mixture of Goltix Titan and Belvedere Extra was the best variant with high efficiency on all three catch crops. Belvedere Extra showed a similar and sufficient effect
1.12 Selection matrix for Brazilian bee species to risk assessment of pesticides
Get PDFMany countries are using honeybee (Apis mellifera) as a surrogate to evaluate the risk of pesticides to all bee species. However, there is uncertainty regarding the extent honey bees can be used as surrogates for non‐Apis species in pesticides risk assessment. A selection matrix for Brazilian bee species was built to support the selection process. To be considered as a candidate representative species in the Brazilian agricultural scenario a bee should have a wide geographic distribution, and be recorded in at least 4 agricultural crops. The selection matrix provides a foundation to elect meliponines (stingless bees) as a priority group. Therefore, in the near future Ibama intends to assess the need for changes in the risk assessment procedure for bees, eventually including a stingless bee as a representative species.Many countries are using honeybee (Apis mellifera) as a surrogate to evaluate the risk of pesticides to all bee species. However, there is uncertainty regarding the extent honey bees can be used as surrogates for non‐Apis species in pesticides risk assessment. A selection matrix for Brazilian bee species was built to support the selection process. To be considered as a candidate representative species in the Brazilian agricultural scenario a bee should have a wide geographic distribution, and be recorded in at least 4 agricultural crops. The selection matrix provides a foundation to elect meliponines (stingless bees) as a priority group. Therefore, in the near future Ibama intends to assess the need for changes in the risk assessment procedure for bees, eventually including a stingless bee as a representative species
1.18 Linking protection goals to trigger values using compound specific properties: Chronic risks to bees
Get PDFIn the EFSA guidance document for the assessment of risk of plant protection products for bees the screening and tier I trigger for chronic risk to bees is linked to a trigger value which is intended to meet a certain level of protection. However, the methods used to derive the trigger of 0.03 do not take into account several factors including the shape and nature of the dose-repose used to generate the endpoint. This means that the resultant proposed trigger leads to a large over estimation of risk with a large number of compounds failing the risk assessment and being incorrectly identified as a higher chronic risk to honey bees. We analyzed the methods used in the selection of the trigger of 0.03 and propose simple adaptations to evaluate all active substances to the same level of protection by taking into account the type of endpoint and the dose response relationship. We found that by using the correct dose-response relationships we could accurately ensure that the desired level of protection was met. We checked our proposal using real-life examples of seven substances registered for use within the European Union and discuss how these proposals could be used to inform risk assessors and risk managers as well as potentially reducing the number of false positive and negatives in a risk assessment.In the EFSA guidance document for the assessment of risk of plant protection products for bees the screening and tier I trigger for chronic risk to bees is linked to a trigger value which is intended to meet a certain level of protection. However, the methods used to derive the trigger of 0.03 do not take into account several factors including the shape and nature of the dose-repose used to generate the endpoint. This means that the resultant proposed trigger leads to a large over estimation of risk with a large number of compounds failing the risk assessment and being incorrectly identified as a higher chronic risk to honey bees. We analyzed the methods used in the selection of the trigger of 0.03 and propose simple adaptations to evaluate all active substances to the same level of protection by taking into account the type of endpoint and the dose response relationship. We found that by using the correct dose-response relationships we could accurately ensure that the desired level of protection was met. We checked our proposal using real-life examples of seven substances registered for use within the European Union and discuss how these proposals could be used to inform risk assessors and risk managers as well as potentially reducing the number of false positive and negatives in a risk assessment
3.11 Bumble bee queen production in semi-field studies: assessment of endpoints and challenges
Get PDFBumble bees (Bombus terrestris L; Hymenoptera, Apidae) provide important pollination services and are commercially used, e.g. in greenhouse cultures. Consequently, the impacts of pesticides on bumble bees were already tested in the past. In the light of the newest EFSA guidance document on the risk assessment of plant protection products for pollinators standardized higher tier studies for pollinators are needed (EFSA 2013). For that reason a ringtest protocol for a bumble bee semi-field study design was developed in the ICPPR Non-Apis working group starting in 2015 to date.The central endpoint in a higher tier bumble bee study is the colony reproduction success (production of young queens, Cabrera et al. 2016). The endpoint is chosen because at the end of the annual life cycle of a bumble bee colony all workers die and only young queens overwinter. Queens that survive establish a new colony in the following year. However, assessing queen reproduction is challenging. Many variables can influence the number of produced queens, such as the right timing for the termination of the study or the condition of the colony at study start. Furthermore, young queen weights are measured. Weight is used as indicator of diapause survival. Literature values of average weight needed for survival before overwintering state 0.8 g for a young queen for successful overwintering (Beekman et al. 1998).Based on data from ring tests of 2016 and 2017 we tried to answer several open questions concerning queen reproduction, i.e. how can the experimental set-up influence queen weights and how high is the natural variation in queen numbers and queen weight/size?Bumble bees (Bombus terrestris L; Hymenoptera, Apidae) provide important pollination services and are commercially used, e.g. in greenhouse cultures. Consequently, the impacts of pesticides on bumble bees were already tested in the past. In the light of the newest EFSA guidance document on the risk assessment of plant protection products for pollinators standardized higher tier studies for pollinators are needed (EFSA 2013). For that reason a ringtest protocol for a bumble bee semi-field study design was developed in the ICPPR Non-Apis working group starting in 2015 to date.The central endpoint in a higher tier bumble bee study is the colony reproduction success (production of young queens, Cabrera et al. 2016). The endpoint is chosen because at the end of the annual life cycle of a bumble bee colony all workers die and only young queens overwinter. Queens that survive establish a new colony in the following year. However, assessing queen reproduction is challenging. Many variables can influence the number of produced queens, such as the right timing for the termination of the study or the condition of the colony at study start. Furthermore, young queen weights are measured. Weight is used as indicator of diapause survival. Literature values of average weight needed for survival before overwintering state 0.8 g for a young queen for successful overwintering (Beekman et al. 1998).Based on data from ring tests of 2016 and 2017 we tried to answer several open questions concerning queen reproduction, i.e. how can the experimental set-up influence queen weights and how high is the natural variation in queen numbers and queen weight/size