The induction of flowering in swedes

Early sowing of swedes increases yield but also increases the risk of bolting. The aim of the study was to investigate vernalisation, that is, low temperature flower induction, of swedes.In a series of experiments, plants of different ages and cultivars were given low temperature treatments of varying duration and tem­perature.Swedes were vernalised by temperatures of 11° and below, the optimum being around 5° to 6° for Wilhelmsburger and 3° to 6° for Doon Major. High temperatures following low temperature treatment and interruptions of treatment with periods at higher temperature were devernalising, reducing the numbers of plants flowering and decreasing the rate of flowering. Stem extension and response of stem growth to gibberellic acid were less affected by devernalisation than flowering.Plants grown at around 15 were found to have a juvenile stage of under A days, some cultivars having a shorter stage of 2 days or less.Low light intensities during vernalisation reduced the number of plants flowering but mature swedes could be vernalised in the absence of light.There was considerable variation in susceptibility to vernalisation in the cultivars used in the experiments. In order of decreasing susceptibility they were Pentland Harvester, Della, Wi1nelmsburger and Marian, Harrietfield, Doon Major and Ruta Otofte. There was evidence of differences in within cultivar variation, early and late flowering selected Wilhelmsburger lines differing more from the parent population in susceptibility to vernalisation than selected Doon Major lines.The longer the duration of low temperature the more plants flowered and the earlier they flowered.The normal site of vernalisation was found to be the growing point although axillary buds could be vernalised in the presence and absence of the growing point. There was no evidence of a trans- locatable flowering stimulus.Methods of selection and shortening the reproductive cycle are described

Nanoelectrodes : energy conversion and storage

Nanosized materials are known to take on peculiar properties compared to the bulk material. Their electronic and mechanical properties are known to improve e.g. higher electrical conductivity and greater strength. Their electrochemical redox properties can change dramatically, e.g. in the case of Ag&deg;, the E&deg; value for Ag&deg; &rarr; Ag+ + e can change by up to half a volt as the particle size decreases. Nanodimensional materials also have an extraordinarily high surface area to volume ratio. All of these properties would bring beneficial effects if they could be retained when the material is assembled into a structure capable of being used as an electrode &ndash; nanostructured electrodes.Here we consider selected examples illustrating the importance of nanostructured electrodes in energy conversion (organic solar cells and fuel cells) and storage (batteries and capacitors). These examples involve the use of inorganic as well as organic conducting and semiconducting materials.<br /