A Critical Appraisal of Methods of Sucrose Analysis in Sugar Beets

Although the parent of the present sugar beet was probably known and used before the building of the pyramid of Cheops (22), it was as recent as 210 years ago that Marggraf obtained the first crystalized sucrose from the root. It was 40 years later before Achard claimed its potentialities as an efficient industry. The product rapidly passed from the status of a luxury to a vital necessity, until today sugar beet production receives some protection or preference in every country where sugar beets are grown. Throughout its 174-year history it has probably been beset with a greater variety of problem and more failures than any other industry before or since. One of the greatest problems has been the actual means of sucrose extraction and determination. The determination of sucrose in sugar beets is the most important function in a beet sugar factory laboratory (3). This value is necessary as the basis for calculations of sugar yields and losses, for fixing the value of beets in factories where these are bought on the basis of their sugar content and for other purposes. Sugar content determinations are also for vital importance to the plant breeder, soil scientist, plant physiologist, and other researchers concerned with sugar beet analysis. Values of such importance should be determined by methods of corresponding accuracy. However, in 1927 Stanek and Vondrak (3) stated that there is no routine method as yet which permits the determination of the sugar in the beet to within an accuracy of 0.1 per cent. It is doubtful that the fundamental accuracy of the saccharimetry methods has improved much since this time. Numerous methods of sucrose analysis are used and are being recommended for use both in sugar beet factory and research laboratories. Although most methods now used are based on the principle of aqueous digestion and single polarimetry, there are wide variations in actual procedures. The available literature is deficient in adequate comparative studies into this problem. It would be of considerable value to researchers in sugar beet production and analysis to know the relative accuracy and precision of these methods and the effects of the several variables now prevalent

Herbicide Resistance in Plants

Economic effects of herbicide resistance. How resistance develops and how its pathways can be used for crop improvement

The Battle for a Sustainable Food Supply

Since the time that Homo sapiens took up farming, a battle has been waged against pests and diseases which can cause significant losses in crop yield and threaten a sustainable food supply. Initially, early control techniques included religious practices or folk magic, hand removal of weeds and insects, and “chemical” techniques such as smokes, easily available minerals, oils and plant extracts known to have pesticidal activity. But it was not until the early twentieth century that real progress was made when a large number of compounds became available for testing as pesticides due to the upsurge in organic chemistry. The period after the 1940s saw the introduction of important families of chemicals, such as the phenoxy acid herbicides, the organochlorine insecticides and the dithiocarbamate fungicides. The introduction of new pesticides led to significant yield increases, but concern arose over their possible negative effects on human health and the environment. In time, resistance started to occur, making these pesticides less effective. This led agrochemical companies putting in place research looking for new modes of action and giving less toxic and more environmentally friendly products. These research programmes gave rise to new pesticide families, such as the sulfonylurea herbicides, the strobilurin fungicides and the neonicotinoid insecticide classes