THE UTILIZATION OF GRASS FED INDOORS TO YOUNG BEEF CATTLE, WITH OR WITHOUT SUPPLEMENTARY BARLEY

An experiment was carried out in which grass was cut and fed indoors, with or without supplementary barley. Seven animals were allocated to each of the following treatments: (1) grass ad lib . without supplementary barley; (2) grass ad lib . with supplementary barley at the rate of 0.5 lb/100 lb bodyweight; (3) grass ad lib . with supplementary barley at the rate of 1 lb/100 lb bodyweight. Supplementary barley increased total dry-matter intake and improved daily liveweight gain and food conversion rate. The mean daily liveweight gains for the 17-week experimental period were 1.60, 1.91 and 2.20 lb and the corresponding feed dry-matter conversion ratios were 6.18, 5.67 and 5.55 for Treatments 1, 2 and 3, respectively.
The dry-matter digestibility of the diets was slightly higher when the grass was supplemented with barley than when grass alone was given. Although barley depressed the digestibility of protein, the absolute and the proportionate retention of nitrogen was increased. This was particularly marked on Treatment 3, presumably because of the higher net energy value of the diet containing the greater amount of barley. The N-retention data corresponded to the rates of liveweight gain obtained.     

Experimental hybridization in certain diploid mexican solanum species

S. bulbocastanum is highly interfertile with S. cardiophyllum. Through the F₁ to F₅ little breakdown due to sterility or lack of plant vigour occurred. F₁ plants of a 5-species hybrid involving S. pinnatisectum, S. trifidum, S. jamesii, S. bulbocastanum, and S. cardiophyllum could also be intercrossed. One-way compatibility was frequently expressed in progenies of these interspecific crosses. It appears to be cytoplasmically controlled, although nuclear factors may be present which interact with cytoplasmic factors. The group of Mexican diploid potatoes represented by these species is potentially interbreeding and shows evidence of introgression throughout its range in central and Western Mexico.Contribution No. 169, Canada Department of Agriculture Research Station, Fredericton, New Brunswick, Canada     

III. Buchbesprechungen

Ohne Zusammenfassung     

Virus infection in South American potatoes

Summary Methods used to test for virus infection in potato samples from South America are described and the incidence of infection in the samples is recorded. Samples were classified according to provenance, ploidy, altitude of collection, and as weed or cultivated forms to investigate the influence of these factors. The advantages of maintenance of potato collections as seed lines are discussed with special reference to prevention of spread of introduced viruses.

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Zusammenfassung Die bei der Untersuchung auf Virusbefall bei Kartoffelmustern aus Südamerika angewendeten Methoden werden beschrieben. Es wird über den Umfang der Infektion durch die Kartoffelviren X(PVX), S(PVS) und Y(PVY) und den nekrotischen Tabakrippenbr?une-Stamm von Virus Y(TVN) in 784 Mustern berichtet, ebenso über das Auftreten von Blattroll in 241 Mustern (Tabelle 1). Um den Einfluss verschiedener Faktoren zu untersuchen, wurden die Muster eingeteilt nach Herkunft (Tabelle 1), Ploidiestufe (Tabelle 2), H?henlage der Herkunftsorte (Tabelle 3) oder nach dem Gesichtspunkt, ob es sich um wilde beziehungsweise unkrautartige oder kultivierte Formen handelte (Tabelle 4). Die Vorteile der Aufrechterhaltung von Kartoffelsammlungen als Samen-Familien werden besprochen, besonders in bezug auf die Verhütung der Ausbreitung von eingeschleppten Viren.

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Résumé L’auteur décrit les méthodes utilisées pour détecter les infections virologiques dans les échantillons de pommes de terre en provenance de l’Amérique du Sud et rapporte l’importance de l’infection par les virus X (PVX), S (PVS), Y (PVY) et par la souche du virus Y causant la nécrose nervienne du tabac (TVN), dans 784 échantillons, et en même temps l’importance de l’infection par le virus de l’enroulement dans 241 échantillons (Tableau 1). Pour déterminer l’influence de ces facteurs, les échantillons ont été classés suivant la provenance (Tableau 1), l’état plo?dique (Tableau 2), l’altitude du prélèvement (Tableau 3), et le fait qu’il s’agit de formes cultivées ou sauvages et adventices (Tableau 4). L’auteur discute de l’opportunité de conserver les collections de pommes de terre sous forme de lignées en semences dans le but particulier d’empêcher l’extension des virus introduits.

     

Beiträge zur phänometrie der kartoffel

Ohne Zusammenfassung Vortrag anl?sslich der 1. Dreijahrstagung der E.G.K.F. in Braunschweig-V?lkenrode in der Sektion “Physiology” am 14. 9. 1960. Saatzuchtleiter, VEG Saatzucht Malchow auf Poel/Kr. Wismar.     

Das Rechnungswesen der Bundesforstverwaltung der USA

Ohne Zusammenfassung     

Triple-cross hybrid kale

A triple-cross method is described as an alternative to the double-cross method for the production in kale of 100 per cent hybrid seed. This new method would reduce the labour involved and improve yields in the early stages of seed multiplication. These advantages would justify slightly lower yields of forage from triple-cross hybrids than from double-crosses.     

Johann Heinrich v. Thünen

European Journal of Forest Research -