Influence of different rates and intensities of light on solanine content and cooking quality of potato tubers

Potato Research - Storage of freshly dug potato tubers for 2 or 4 hours in bright sunlight resulted in only minor changes in the solanine content. A significant increase in solanine in tubers...     

Increasing the competitiveness of wood in material substitution: A method for assessing and prioritizing customer needs

To increase the competitiveness of wood as a building material requires knowledge of which customer needs require attention in terms of quality improvement and/or product development to best satisfy customers. Hence, information as to the impact on customer satisfaction of the fulfillment of different customer needs, as well as the performance of wood and substitutes in providing for these needs, is needed. This article suggests the use of customer satisfaction modeling (CSM) for assessing customer needs. The methodology is evaluated in the context of floorcovering. The results suggest that CSM is well suited for extracting the information necessary for prioritizing customer needs: importance/impact and performance data for attributes as well as for customer benefits. The study indicates the necessity of considering substitute materials not only for performance comparisons; substitutes may also reveal otherwise latent customer needs. Practical, functional, benefits exert the greatest impact on customer satisfaction for wooden flooring as well as its closest substitutes, laminate and carpet. Hygiene and a low cost over the life cycle are apparently the customer benefits that require attention from wooden flooring manufacturers, because importance is high and performance relatively low.     

Dietary Trace Metal Supplements Promote Blood Vessel Melanosis in Fillets of Juvenile Farmed Atlantic Cod,Gadus morhua L.

Chronic over‐exposure to diet‐borne copper has been implicated in the development of black stripes caused by melanin deposits (melanosis) around the blood vessels in fillets of farmed Atlantic cod, Gadus morhua L. To test this hypothesis a 6‐mo pilot study using feeds containing controlled amounts of copper has been performed. Cumulative data from each feed group showed that 56% of cod fed a diet containing 10 mg/kg of added copper had black stripe while 58% of cod on a diet containing 5 mg/kg of added copper were affected. Cod on a diet with no added copper had 33% of individuals positive for black stripe, and in a final group on a diet containing no supplementary trace metals and minerals 16% of individuals were affected. Weight gain, increase in length, hepatosomatic index, and condition factor were unaffected by the changes made to mineral supplements. Melanosis has been observed in 24% wild cod of market size (n = 30) whilst 85% of market‐sized farmed cod examined have had black stripe (n = 403).     

The effect of temperature on sensory quality,chemical composition and growth of carrots (Daucus carota L.). IL Constant diurnal temperatures under different seasonal light regimes

Summary

Carrots of cv. Panther F1 were grown in climate chambers at 9, 12, 15, 18 and 21°C, constant diurnal temperatures at three different periods of the year. The effect of varying solar radiation and temperatures were evaluated on growth, sensory attributes and chemical composition. Higher levels of light significantly increased most chemical and physical variables of the carrot roots. Temperature was the most important factor determining the variation in sensory and chemical variables, whereas for morphological features like root weight, root length and diameter measurements, light was more important than temperature. Principal component analysis (PCA) of chemical and physical variables explained 85% of the total variation by the first three principal components, the first component (PCI) being defined by physical variables, explained 46% of the variation, while the temperature related PC2 explained 32% of the variation. Prediction of sensory variables by chemical or physical variables by means of partial least square (PLS) was higher at low light intensity than at high light intensity.     

Influence of potassium supply and storage conditions on the discoloration of raw and cooked potato tubers of cv. Pimpernel

Summary Potato tubers of Pimpernel, grown at 18 levels of K or NPK supply, were assessed for enzymic browning and after-cooking discoloration after different treatments. The influence of potassium supply during the previous 30 years and in the year of growing on enzymic browning was pronounced. Enzymic browning of the tubers showed a strong negative correlation with concentration of potassium in tubers and haulm sampled at harvest. A significant, but less strong relationship between tuber colour and potassium in tubers and haulm was found for after-cooking discoloration. An increase in enzymic browing and after-cooking discoloration took place during the first 3 months of storage, but not during the next 3 months. Less enzymic browning occurred after 3 months of storage at 12°C than at 3°C. Storing at 0°C for 3 days in the fall had little affect on enzymic browning, whereas conditioning at 16°C slightly decreased enzymic browning.

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Zusammenfassung Aus zwei Langzeit-Feldversuchen wurden 1969 Kartoffelknollenmuster der Sorte Pimpernel gezogen. In diesem Versuch wurden 18 Stufen von K-oder NPK-Gaben verglichen (Tabellen 1 und 2). Die Verf?rbung von rohen und gekochten Knollen (Tabelle 3) wurde beurteilt, und in Knollen-und Krautmustern (Entnahme bei der Ernte) wurde der Kaligehalt bestimmt. Der Einfluss der Kaligabe w?hrend der vorhergehenden 30 Jahre und in Jahre 1969 auf die enzymatische Verf?rbung war deutlich (Abb. 1, Tabelle 4). Wo die Durchschnittsgaben von Kalium in früheren Jahren weniger als 70 kg/ha betrugen, trat eine betr?chtliche Verbesserung in der Farbe ein, wenn die Gabe im Anbaujahr von 100 auf 200 kg/ha erh?ht wurde (Abb. 2). Die Farbe der rohen Knollen war jedoch selbst bei einer Düngung mit 200 kg/ha unbefriedigend bei Parzellen, bei denen in früheren Jahren die Kaliversorgung im Boden auf einem tiefen Stand war. Die Verf?rbung nach dem Kochen war weniger ausgepr?gt und weniger beeinflusst durch die Kaligabe als die enzymatische Braunverf?rbung (Tabelle 4). Der Kaligehalt in % in Knollen und Kraut (Musterentnahme bei der Ernte) war in enger Beziehung zu der enzymatischen Braunverf?rbung, und es bestand eine signifikante, aber weniger enge Korrelation mit der Verf?rbung nach dem Kochen (Abb. 3 und 4). Die Braunverf?rbung der rohen Knollen und die Verf?rbung nach dem Kochen nahmen in den drei ersten Monaten der Lagerung zu, aber nicht w?hrend der drei folgenden Monate. Die Rohverf?rbung war nach einer dreimonatigen Lagerung bei 12°C schw?cher als bei 3°C. Setzte man Knollen für drei Tage im Herbst einer Temperatur von 0°C aus, so hatte dies wenig Einfluss auf die Rohverf?rbung (Tabelle 4). Konditionierung w?hrend 7 Tagen bei 16°C verbesserte die Farbe der rohen Knollen leicht (Tabelle 5). Die Ergebnisse umfassen vor allem die Stufen unter der optimalen Kaligabe. Ein Ueberschuss an Kali wurde wahrscheinlich nicht erreicht.

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Résumé On a prélevé, en 1969, des échantillons de tubercules de pomme de terre, variété Pimpernel, dans des essais en champ de longue durée, dans lesquels ont été comparés 18 doses de K ou de NPK (tableaux 1 et 2). On a établi la décoloration sur les tubercules crus et cuits (tableau 3), et on a déterminé le potassium dans les tubercules et les tiges échantillonnés à la récolte. L'influence de l'approt de potassium au cours des trente années antérieures et au cours de la dernière année (1969) sur le brunissement enzymatique est prononcée (fig. 1, tableau 4). Là où les doses moyennes de potassium au cours des années précédentes sont inférieures à 70 kg/ha, il appara?t une amélioration considérable dans la couleur lorsque l'apport de potasse, lors de la dernière végétation, atteint 100 à 200 kg/ha (fig. 2). Cependant la couleur des tubercules crus n'est pas satisfaisante, même apr⪻s une fumure de 200 kg/ha sur les parcelles où le potassium du sol a été maintenu à un niveau bas pendant les années précédentes. Après cuisson, l'altération de la couleur est moins grave et moins influencée par l'approt potassique que le brunissement enzymatique (tableau 4). Le pourcentage de potassium dans les tubercules et les tiges, échantillonnés à la récolte, montrent une relation étroite avec le brunissement enzymatique, et une corrélation significative moins étroite avec la décoloration aprés cuisson (fig. 3 et 4). Le brunissement enzymatique et la décoloration après cuisson augmentent au cours des trois premiers mois de conservation, mais non pas durant les trois derniers mois. Il appara?t moíns de brunissement enzymatique après trois mois de conservation à 12°C plut?t qu'à 3°C. Soumettre brusquement les tubercules à 0°C pendant trois jours a peu d'effet sur le brunissement enzymatique (tableau 4). Le fait de placer les tubercules pendant 7 jours à 16°C améliore légèrement la couleur des tubercules crus (tableau 5). Les résultats se rapportent le plus exactement aux niveaux situés en-dessous de l'apport optimum de potassium. On n'a probablement pas atteint l'excès de potassium.

     

Influence of placement method and water supply on the uptake of phosphorus by early potatoes

Summary The fertilizer phosphorus concentration in potato leaves, at four successive stages of a 10-week growing period was higher in the banding than in the broadcast treatment. The difference between the treatments was greatest in the early growth stages, decreasing rapidly towards harvest. Fertilizer P, accumulated in haulm and tubers, was on the average, 149 and 288 mg per plot for broadcasting and banding, respectively. The uptake of indigenous P and yield of tubers were little influenced by the method of placement. The utilization of fertilizer P was 1–5% for broadcasting and 5–9% for banding. Under dry growing conditions, the absorption of soil P and fertilizer P was greatly reduced. Banding greatly reduced the adverse effect of drought on phosphorous uptake. An improved water supply increased the utilization percentage of broadcast as well as that of banded phosphorus.

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Zusammenfassung 1968 wurde ein Kleinparzellen-Feldversuch durchgeführt, in dem Band- und Fl?chendüngung mit Phosphor zur frühen Kartoffeln (SorteSirtema) bei drei verschieden grossen Wassergaben miteinander verglichen wurden. Der Versuch wurde 1969 wiederholt (SorteSaskia) (Tabelle 1). Phosphor wurde als L?sung in Form von Ca(H₂PO₄)₂ in gleichwertigen Mengen zu 30 und 60 kg P pro ha gegeben. Die Mengen an radioaktivem Phosphor betrugen 3 mCi pro m². Das Phosphordüngerband befand sich 2 cm unter und 5 cm neben der Knolle, w?hrend die Phosphor-Fl?chendüngung gleichm?ssig auf zwei Schichten, 2 cm und 3 cm unter die Bodenoberfl?che, ausgebracht wurde. Muster der Endfiederbl?tter des obersten, voll entwickelten Blattes — vier, fünf, sieben und zehn Wochen nach dem Pflanzen — sowie Knollen- und Stengelmuster —bei der Ernte (zehn Wochen nach dem Pflanzen) gezogen — wurden auf den Gehalt an Gesamt-P und radioaktivem P untersucht. Die Dünger-Phosphorkonzentration in Kartoffelbl?ttern war bei vier aufeinander folgenden. Stadien einer zehnw?chigen Wachstumsperiode beim Bandverfahren h?her als beim Fl?chenverfahren. Der Unterschied zwischen Fl?chen- und Banddüngung fiel bei der ersten Probeentnahme am gr?ssten aus; gegen die Ernte wurde er kleiner (Abb. 1). Die bis zur Ernte in den Knollen und Stengeln angereicherte Gesamtmenge an Dünger-P war infolge des Bandverfahrens stark angestiegen (Tabelle 2), w?hrend die Menge an absorbiertem Boden-P und der Knollenertrag durch die Placierungsmethode nur leicht beeinflusst wurden (Tabelle 5 und 6). Die Verwertung des Dünger-P betrug nur 1–5% beim Fl?chenverfahren und 5–9% beim Bandverfahren (Tabelle 4). Unter sehr trockenen Wachstumsbedingungen war die Aufnahme an Gesamt-P und Dünger-P stark reduziert. Banddüngung jedoch verringerte wirksam den ungünstigen Einfluss der Trockenheit auf die Phosphoraufnahme (Tabelle 2–5). Wenn die Wasserversorgung verbessert wurde, stieg der Verwertungsprozentsatz sowohl im Fl?chen-als auch im Bandverfahren.

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Résumé On a exécuté en 1968 (var.Sirtema) et répété en 1969 (var.Saskia) une expérience en petites parcelles au champ pour comparer l'application de phosphore en bande ou à la volée à des pommes de terre hatives sous trois niveaux différent d'approvisionnement en eau (Tableau 1). Le phosphore a été applique en solution sous forme de Ca (H₂PO₄)₂ et en quantités équivalentes à 30 et 60 kg de P par ha. Les quantités de radiophosphores étaient de 3 mCi par m². La situation de la bande de phosphore était la suivante: 2 cm en-dessous et 5 cm de chaque c?té du tubercule, tandis que le phosphore épandu à la volée était également réparti en deux couches à 2 et 3 cm en-dessous de la surface du sol. On a analysé la teneur en phosphore total et radioactif des folioles terminales de la feuille supérieure pleinement développée prélevées quatre, cinq, sept et dix semaines après la plantation, ainsi que des tubercules et tiges prélevés à la récolte dix semaines après la plantation. La concentration en fertilisant ‘phosphore’ dans les feuilles de Pomme de terre, à quatre stades successifs d'une période de croissance de dix semaines, était plus élevée dans le traitement en bande que dans le traitement à la volée. La différence entre ‘volée’ et ‘bande’ était la plus élevée au premier échantillonnage et décroissait jusqu'à la récolte (Fig. 1). La quantité totale de fertilisant ‘phosphore’ accumulé dans les tubercules et tiges à la récolte était grandement accrue par l'épandage en bande (Tableau 2), tandis que la quantité de P absorbée par le sol et la production de tubercules était légèrement influencés par la méthode de placement (Tableau 5 et 6). L'utilisation de fertilisant P ne dépasse pas 1–5% pour l'épandage à la volée et 5–9% pour l'épandage en bande (Tableau 4). Sous des conditions très séches de croissance, le prélèvement de phosphore total et de phosphore fertilisant était fortement réduit. Cependant l'épandage en bande réduit effectivement l'effet nuisible de la sécheresse sur le prélèvement de phosphore (Tableau 2–5). L'amélioration de l'approvisionnement en eau augmente le pourcentage d'utilisation du phosphore épandu à la volée aussi bien qu'en bande.

     

Aviary Systems and Conventional Cages for Laying Hens: Effects on Production,Egg Quality,Health and Bird Location in Three Hybrids

Abstract

In two experiments, a total of 4346 laying hens housed in battery cages, with three hens per cage (C), and in two aviary systems, both with tiered wire floors and litter (Lövsta with two tiers (L) and Marielund with three tiers (M)), were used for studies on production, egg quality, health, plumage and foot condition, bone strength and bird location. Three hybrids were used: Lohmann Selected Leghorn (LSL) were kept in all three systems, Dekalb XL (DK) were kept in both aviaries and Lohmann Brown (LB) in M only. Production and feed conversion in M were inferior but not significantly different from C but significantly better than in L. Proportions of dirty eggs were significantly higher in the avaries. No significant differences were found in interior egg quality traits between keeping systems. LSL showed higher production and better feed conversion than the other hybrids and a tendency for a lower proportion of mislaid eggs. Mortality varied considerably between the aviary pens, reaching 35% in LB mainly owing to cannibalism and salpingitis. Keel bone lesions and bumble foot appeared in the aviaries, while toe pad hyperkeratosis was observed in C. Hens in aviaries had significantly stronger bones (tibia and humerus) and showed more wounds from pecks, inferior plumage condition and dirtier feet than in C. LSL had more bumble foot injuries than LB but better plumage condition than DK. The birds used the different parts in the aviaries well, especially the perches on the resting top tier during the night.     

Traps containing acaricides for the control of Dermanyssus gallinae

In Sweden, the poultry red mite, Dermanyssus gallinae, is the only haematophagous mite of poultry. After obtaining a blood meal the parasite spends most of its life off the host aggregated in cracks and crevices where mating and reproduction occur. Cardboard traps (1000 mm x 40 mm x 3 mm; 160 mm x 140 mm x 3 mm and 100 mm x 70 mm x 3 mm) containing 2% metriphonate were placed where mites gathered, out of reach of the hens, in two different types of multi-tiered floor systems for layers. In two separate trials, treated traps were replaced every second day for 2 weeks and every week for 8 weeks. In the 2-week trial the whole floor system was treated while in the 8-week trial six of 12 existing compartments studied were treated. The untreated compartments were used as controls. Throughout the study, the parasite populations were monitored by collections of mites with untreated cardboard traps (100 mm x 70 mm x 3 mm). A 95% reduction of mites was recorded in the 8-week trial whereas a 99% reduction of mites was recorded in the 2-week trial. The placement of treated traps near mite aggregation sites was essential for satisfactory control.     

Environmental problems,productivity and innovations in Norwegian salmon aquaculture

Abstract

Environmental issues have been of central importance throughout the history of salmon aquacuiture in Norway. In this paper we will examine some of the issues, and show that while there are still problems, many have also been resolved. A major reason for this is the fact that salmon farmers have internalized many of the environmental effects into their decision‐making due to the relationship between environmental impact and productivity. Another reason, particularly when it comes to treatment of diseases, is that lack of private innovative activity due to different market failures has been compensated for by government‐sponsored research and development.