Tissue composition and arrangement in sugar beet genotypes of different tissue strength with regard to damage and pathogen infestation

Nelia Nause; Tobias Meier; Christa M. Hoffmann

Drought stress affects yield formation and quality of sugar beet. The aim of this study was to identify the growing period, in which drought stress has the greatest impact on growth, and furthermore, to analyze the response of different sugar beet genotypes. Causes for a different response should be identified. In pot experiments in the greenhouse, drought stress was simulated by reducing irrigation to 60% of the water holding capacity (WHC) for four weeks at various growth stages followed by re-watering. Growth reduction was greatest when drought stress occurred early in the season: the content of the quality-determining non-sugars was highest, sugar yield and beet diameter were lowest. Responses of the genotypes in sugar yield, but primarily in the accumulation of osmotically active substances differed. Despite re-watering after drought stress the restrictions could not be compensated during growth. The transpiration coefficient of the drought-stressed treatments was only slightly different to the control, because water consumption in the control did not either increase at average air temperatures beyond 23 °C. The strong effect of early drought stress could be attributed to the high growth rates, so that a limited water supply affected yield formation more than at later growth stages. The storage losses of sugar beet genotypes are closely related to damage during harvest and subsequent infestation with mould and rots. Genetic variation for storability seems to be primarily linked to textural properties of the roots such as the resistance against mechanical damage. However, no information is available about the tissue strength, tissue composition and structural organization leading to an enhanced resistance against damage and pathogen attack. Therefore, the aims of the study were the identification of genotypic differences concerning tissue strength of the beet, the relation to damage and pathogen infestation and the underlying physiological basis of tissue strength. Field trials were carried out with 6 genotypes at 2 locations in 2018. The roots were harvested in August and November. After harvest in November, a storage trial was carried out. The root strength increased from August to November. Beets with a high puncture resistance of the periderm also had a firm inner tissue. Genotypic differences in puncture resistance were not affected by the harvest time, indicating that this trait is stable throughout the growing period. A higher puncture resistance of the beet was related to a lower mould growth during storage. Genotypes with varying tissue strength also differed in fiber content (AIR), but the composition of AIR was stable over genotypes. The number of cambium rings seems not to essentially influence the tissue strength of the beet. In the further course of the project, microscopic analyzes will clarify, whether genotypic differences in tissue strength can be attributed to cell size or cell wall thickness.

2020 (144) 114-123
Language: E

Early drought stress: Effects on yield formation and quality of sugar beet

Henning Ebmeyer; Christa M. Hoffmann

Drought stress affects yield formation and quality of sugar beet. The aim of this study was to identify the growing period, in which drought stress has the greatest impact on growth, and furthermore, to analyze the response of different sugar beet genotypes. Causes for a different response should be identified. In pot experiments in the greenhouse, drought stress was simulated by reducing irrigation to 60% of the water holding capacity (WHC) for four weeks at various growth stages followed by re-watering. Growth reduction was greatest when drought stress occurred early in the season: the content of the quality-determining non-sugars was highest, sugar yield and beet diameter were lowest. Responses of the genotypes in sugar yield, but primarily in the accumulation of osmotically active substances differed. Despite re-watering after drought stress the restrictions could not be compensated during growth. The transpiration coefficient of the drought-stressed treatments was only slightly different to the control, because water consumption in the control did not either increase at average air temperatures beyond 23 °C. The strong effect of early drought stress could be attributed to the high growth rates, so that a limited water supply affected yield formation more than at later growth stages.

2020 (144) 104-113
Language: E

Competitiveness of different sugarcane industries in an era of low sugar prices

L. Jean Claude Autrey; L. Jolly; P. Leste de Périndorge

A surplus in global production over consumption in 2017-18, initially projected at 10 mn t of sugar mainly from boosted production in India, Thailand, European Union and other countries, resulted in a 10-year low price of sugar in August 2018. Due to the low price environment seen in 2017-18, even the most efficient sugar producing countries such as Brazil had production cost higher than the world market price. It was opportune to study the competitiveness of different sugarcane industries in Southern, Eastern, Central and Western Africa in comparison with large producers such as Brazil, India, Thailand and Australia. Parameters measured included the general situation of each industry, the production of cane (area cultivated, yield, productivity, cane quality, harvest and control, performance of small producers, price of cane and research, development and extension), milling of cane (number of factories, sugar production, milling efficiency, price of sugar locally and internationally) and diversification (biofuel, electricity cogeneration and others). The technical performance indicators usually used by sugar analysts across the world were used to compare the technical efficiency of the industries concerned in relation to their regional and world competitors. National policies implemented in each country were analysed. Explicit lessons were drawn from the complexity and diversity of sugar policy applied to industries around the globe. Armed with these lessons, stakeholders should be able to develop a reformed policy tool box for the sugar industry that will allow it to achieve the required efficiency at all levels.

2020 (144) 94-103
Language: E

SugarProTech Facts 1 Impact of beet quality on sugar manufacture Part 1. General considerations of the technological beet quality

Jan Maarten de Bruijn

Without doubt, the sugar content is the major quality parameter of sugar beets. The amount of sugar which can be crystallized as white sugar in processing is often predicted using empirical formula. These formulas are usually based on the potassium, sodium and amino-nitrogen content of the beets. The amount of sugar that cannot be crystallized (i.e. the sugar contained in molasses) is related to these internal quality parameters. However, from a process technology perspective other beet quality parameters play an important role too and may have a considerable impact on the efficiency of beet processing and thus production costs. The first part of this paper presents an overview of the technologically considered important external and internal beet quality parameters and how they affect processing.

2020 (144) 86-93
Language: E

Legionella in factory water systems – a regulated future

Christer Bergwall

Legionella are pathogenic fresh water bacteria in natural and manmade water systems with a unique water-to-air transmission route. The water temperature is an important factor influencing the colonisation of water systems. Potential critical areas are cooling water, wet scrubbers, sanitary water systems, and aerobic part of wastewater treatment plants. The most recent legislation in Europe, 42nd German Federal Immission Control Act, regulates the technical and organizational requirements for the operators of evaporative cooling, cooling towers, and wet scrubber systems. The regulation specifies two test and one action limit for Legionella and the required measures when exceeding each limit. The reference method, ISO 11731:2017, has disadvantages e.g. analysis time of 7–10d and interfering non-Legionella bacteria that can give false negative results. Alternative methods includes quantitative PCR and fluorescence in situ hybridisation (FISH). Both methods are suitable for in-house evaluation of Legionella. The operation of Legionella positive system is a challenge mainly due to significant resistance to biocides when the bacteria are associated with biofilms. Preventative and corrective actions with focus on cooling water systems are summarised.

2020 (145) 31-36
Language: E

Geometrische und spektrale Erfassung von Bestandeseigenschaften zur Phänotypisierung von Zuckerrüben und Weizen

David Bohnenkamp; Stefan Paulus; Anne-Katrin Mahlein

Monitoring von Pflanzen mit nicht-destruktiver Sensorik ist ein etabliertes Werkzeug bei der Begutachtung und Beschreibung pflanzlicher Entwicklung und Leistungsfähigkeit. Diese Methoden werden im Labor- und Gewächshaus auf Organ-, Pflanzen-, und Kleinbestandebene eingesetzt. Hochdurchsatzverfahren sind ebenfalls etabliert. Die Übertragung dieser Techniken auf die Feldebene ermöglicht die Validierung von Resultaten aus kontrollierten Bedingungen und eine Integration in Prozesse des Anbaumanagements. Dazu müssen die Sensoren auf mobilen Trägerplattformen angebracht werden. Hierbei kommen neben manuell verschiebbaren Stativen auch radgestützte Versuchsträger (Roboter, Geräteträger und Traktoren) oder luftgestützte Plattformen (Drohnen, Hubschrauber, Flugzeuge, Satelliten) jeweils bemannt oder unbemannt zum Einsatz. Je nach Trägerplattform variiert der Messaufbau, der Abstand zwischen Sensor und Pflanze, der Durchsatz und somit die Auflösung bzw. die Möglichkeit, Details zu erkennen. Im folgenden Text werden Versuche mit drei unterschiedlichen experimentellen Trägerplattformen – (i) stativgebunden, (ii) auf einer mobilen Verfahreinheit mit Linearachse (Phytobike) und (iii) Drohne – dargestellt, um pflanzliche Parameter auf verschiedenen Skalenebenen im Feld zu untersuchen. Mit einer Drohne wurde in Zuckerrüben der Bedeckungsgrad quantifiziert, während mit Stativmessungen eine Unterscheidung zwischen gesunden und mit Cercospora beticola inokulierten Parzellen dargestellt wurde. Der geringste Abstand zwischen Pflanze und Sensor wird mit dem System Phytobike erreicht. Damit konnten auf Weizenblättern Gelbrostsymptome detektiert und quantifiziert werden.

2020 (145) 53-58
Language: D

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