Productivity and management of rice–wheat cropping systems: issues and challenges

Rice (Oryza sativa L.) and wheat (Triticum aestivum L.) are now grown in sequence on the same land in the same year over 26 Mha of South and East Asia to meet the food demand of a rapidly expanding human population. This rice–wheat (R–W) system brings together conflicting and complementary practices. Much of the system operates at low yield because of inadequate nutrients and inappropriate water management. The challenge to research is to understand crop responses to the required combination of practices so that management systems can be devised for high and sustainable combined yield. The repeated transitions from anaerobic to aerobic to anaerobic growing conditions affect soil structure, nutrient relations, the growth of the component crops, and their associated pests and diseases. This review establishes realistic yield targets and discusses strategies and tactics to improve complementarity of the two crops by choice of cultivar, sowing time, mechanization, soil and water management, choice and combination of organic and inorganic fertilizers, management of weeds, pests and diseases, and the inclusion of other crops into the system, especially legumes. While research must attend to existing problems and improve resource-use efficiency of existing practices, the review suggests the need to look for new production strategies that might avoid existing constraints in some areas of the R–W region. In particular, soil, water and nutrient management strategies, such as reduced tillage and use of raised beds, that avoid the deleterious effects of puddling on soil structure and fertility, improve water- and nutrient-use efficiencies, and increase crop productivity, may be appropriate.     

Amylases and bread firming – an integrated view

Despite much research, bread crumb firming during storage and amylase anti-staling properties are still ill understood. We present a coherent view on the topic based on literature, experimental data, and food polymer science-related concepts. During bread storage, the gelatinised starch (amylopectin) network, present in soft, fresh bread, is gradually transformed into an extensive, partially crystalline, permanent amylopectin network, with amylopectin crystallites acting as junction zones. This network increasingly accounts for the bulk rheological behaviour of aging bread crumb. Furthermore, as amylopectin retrogradation proceeds, moisture migration within the crumb structure occurs, and more and more water is immobilised within amylopectin crystallites. The crystalline hydrate water can no longer plasticise the different networks, which goes hand in hand with increased crumb firmness and decreased crumb resilience, due to a less flexible gluten network. The efficiency of anti-staling amylases can be related to the extent they limit the formation and the strength of the permanent amylopectin network, and the water immobilisation. Conventional alpha-amylases weaken the amylopectin network by cutting the long polymer chains connecting the crystalline regions, but have little effect on amylopectin recrystallisation. In contrast, maltogenic alpha-amylase primarily shortens the amylopectin side chains, thus hindering amylopectin recrystallisation, and the concomitant network formation and water immobilisation.     

Amylases and bread firming – an integrated view

Despite much research, bread crumb firming during storage and amylase anti-staling properties are still ill understood. We present a coherent view on the topic based on literature, experimental data, and food polymer science-related concepts. During bread storage, the gelatinised starch (amylopectin) network, present in soft, fresh bread, is gradually transformed into an extensive, partially crystalline, permanent amylopectin network, with amylopectin crystallites acting as junction zones. This network increasingly accounts for the bulk rheological behaviour of aging bread crumb. Furthermore, as amylopectin retrogradation proceeds, moisture migration within the crumb structure occurs, and more and more water is immobilised within amylopectin crystallites. The crystalline hydrate water can no longer plasticise the different networks, which goes hand in hand with increased crumb firmness and decreased crumb resilience, due to a less flexible gluten network. The efficiency of anti-staling amylases can be related to the extent they limit the formation and the strength of the permanent amylopectin network, and the water immobilisation. Conventional alpha-amylases weaken the amylopectin network by cutting the long polymer chains connecting the crystalline regions, but have little effect on amylopectin recrystallisation. In contrast, maltogenic alpha-amylase primarily shortens the amylopectin side chains, thus hindering amylopectin recrystallisation, and the concomitant network formation and water immobilisation.     

DNA and the chromosome – varied targets for chemotherapy

The nucleus of the cell serves to maintain, regulate, and replicate the critical genetic information encoded by the genome. Genomic DNA is highly associated with proteins that enable simple nuclear structures such as nucleosomes to form higher-order organisation such as chromatin fibres. The temporal association of regulatory proteins with DNA creates a dynamic environment capable of quickly responding to cellular requirements and distress. The response is often mediated through alterations in the chromatin structure, resulting in changed accessibility of specific DNA sequences that are then recognized by specific proteins. Anti-cancer drugs that target cellular DNA have been used clinically for over four decades, but it is only recently that nuclease specific drugs have been developed to not only target the DNA but also other components of the nuclear structure and its regulation. In this review, we discuss some of the new drugs aimed at primary DNA sequences, DNA secondary structures, and associated proteins, keeping in mind that these agents are not only important from a clinical perspective but also as tools for understanding the nuclear environment in normal and cancer cells.     

Effect of plant fruits – Indian gall nut,bedda nut and gooseberry – on hypercholesterolemic rats

The effect of supplementation of three fruits, Indian gall nut, bedda nut and gooseberry, on serum lipid levels and excretion of bile acids was investigated. Rats made hypercholesterolemic by feeding hypercholesterolemia inducing diet (HID) for a period of 30 days were used as the test model. Feeding of a dried powder of these fruits along with the HID resulted in significant (p<0.01) reduction in total cholesterol, LDL cholesterol and triglycerides. HDL cholesterol remained unchanged in groups fed gall nut and bedda nut. However, the levels were significantly (p<0.01) higher in groups fed mixed and gooseberry diets in comparison to the control diet. Excretion of bile acids was found to be significantly (p<0.01) higher in animals receiving the three fruits in combination in comparison to those receiving the individual fruits.     

Collaboration and distances between German immunological institutes – a trend analysis

Background

The hypothesis that distance matters but that in recent years geographical proximity has become less important for research collaboration was tested. We have chosen a sample–authors at German immunological institutes–that is relatively homogeneous with regard to research field, language and culture, which beside distance are other possible factors influencing the willingness to co-operate. We analyse yearly distributions of co-authorship links between institutes and compare them with the yearly distributions of distances of all institutes producing papers in journals indexed in the Science Citation Index, editions 1992 till 2002. We weight both types of distributions properly with paper numbers.

Results

One interesting result is that place matters but if a researcher has to leave the home town to find a collaborator distance does not matter any longer. This result holds for all years considered, but is statistically most significant in 2002. The tendency to leave the own town for collaborators has slightly increased in the sample. In addition, yearly productivity distributions of institutes have been found to be lognormal.

Conclusion

The Internet did not change much the collaboration patterns between German immunological institutes.

     

Genetics and chemistry of pigments in wheat grain – A review

Cereal grains contain many phytochemicals, some of which significantly influence the grain colour. Anthocyanins are accumulated in the aleurone or pericarp layer and give blue, purple or combination of these colours. Flavonoids, such as yellow C-glycosides of flavones, flavonols, flavanonols, proanthocyanidins and reddish-coloured phlobaphenes are mainly present in the outer layer of grains while carotenoids that are responsible for yellow grain are in the endosperm. Therefore, accumulation of these pigments in the grain can represent an important target in breeding programmes aimed at increasing the concentrations of bioactive components in grain and products. This review therefore summarises our current knowledge of anthocyanin and carotenoid pigments, their genetic control and variation in levels in different wheat lines.     

Fatty acids of maize pollen – Quantification,nutritional and morphological evaluation

The aim of this work was to identify and quantify fatty acids presented in pollen samples collected from six different Serbian maize hybrids by GC capillary method. Due to great importance of fatty acids as food component potential nutritional value of maize pollen as food supplement in human diet was determined. It has been shown that pollen is a great source of different fatty acids, especially unsaturated fatty acids. In total, twenty eight fatty acids were quantify - the most abundant saturated FAs were palmitic and henicosanoic acid; the most prevalent monounsaturated FAs were oleic, elaidic and cis-10-heptadecenoic acid. Linoleic and cis-11,14-eicosadienoic acid were the most abundant polyunsaturated fatty acid. Also, it was found that FAs composition was significantly influenced by the type of maize hybrids. According to nutritional recommendations, four of six pollen samples had good nutritional quality with unsaturated/saturated fatty acids ratio higher than 1.6, but there is unsatisfied distribution of ω-6 and ω-3 fatty acids as the most important type of unsaturated fatty acids.     

New winter oilseed rape varieties – seed quality and morphological traits depending on sowing date and rate

Many studies have focused on research about impact of time and density of sowing on the agronomic characteristics of different crops. However, the number of studies investigating such a response on the qualitative composition of different types of winter oilseed rape varieties is still limited. The aim of the research was to determine the effect of sowing date and density on yield, protein and oil content and quality of winter oilseed rape varieties: open-pollinated, a typical hybrid of traditional type of growth and a new semi-dwarf hybrid, which biology and yielding have not been thoroughly established. This experiment was conducted applying four sowing dates (August 14, August 25, September 4, September 15), three winter oilseed rape cultivars (PR45D03 -semi-dwarf hybrid, PR46W31 – hybrid, Californium – open-pollinated) and four sowing rates (30, 40, 50, 60 seeds/m²). Among the compared sowing dates, August 25 proved to be optimal for yielding of the tested winter oilseed rape cultivars. Semi-dwarf variety contained less protein and glucosinolate in seeds, but more oil in comparison to other studied varieties (hybrid and open-pollinated). The yields did not differ significantly within a density of 40, 50, 60 seeds/m², so it is important result, especially for the agricultural practice.     

Selenium Biofortification of Agricultural Crops and Effects on Plant Nutrients and Bioactive Compounds Important for Human Health and Disease Prevention – a Review

Plant Foods for Human Nutrition - Selenium supplementation in humans has been suggested for the prevention of chronic diseases including cardiovascular disease, cancer, and neurodegenerative...     

Cool Farm Tool – Potato: Model Description and Performance of Four Production Systems

The Cool Farm Tool – Potato (CFT-Potato) is a spreadsheet programme that allows the calculation of the amount of CO₂ equivalents that it costs to produce 1 t of potato. The spreadsheet was adapted from an original generic version of the tool, and completed for potato production in diverse production areas in the world applying different levels of technology. The CO₂ embedded in chemicals during their production and released from the soil after nitrogen fertilization in the CFT-Potato has been updated to consider more recent products and production methods. Energy costs of the operations in the original version taken from generic data provided by the American Society of Agricultural and Biological Engineers Standard, however, were altered (usually increased) where there was evidence from practical sources that the original figures did not apply. For example, the figure of around 16 l of diesel per ha for potato harvesting in the original version was corrected to 60 l of diesel per ha based on observational data. Figures for typical potato operations such as windrowing were supplied. Irrigation with pumps powered by diesel or electricity from the grid, with a centre pivot, a rain gun, drip irrigation and flooding and energy cost for extracting water from deeper sources were also added. We added data for grading, washing, store loading and unloading, the application of a sprout suppressant and storage with ventilation of ambient air or forced refrigeration. The CFT-Potato can be used by growers to calculate the actual costs of 1 t of potato in terms of kilograms CO₂ and explore the repercussion of altered management options. Here the comparison of four potato production systems in the Netherlands is shown: seed potatoes (115 kg CO₂/t), table potatoes (77 kg CO₂/t), starch potatoes (71 kg CO₂/t) and organic potato (82 kg CO₂/t). Based on potato dry matter, however, starch potato has the lowest footprint mainly due to the extensive use of pig slurry of which the production and transport CO₂ costs are attributed to the pig production chain.     

Traditional production,consumption and storage of Kunu – a non alcoholic cereal beverage

A survey of the production, consumption and storage ofKunu was carried out. Some of the information included consumption rate, processing techniques andequipment, producer's status and grains used. About73% consume Kunu daily, 26% occasionally; 1% knowit is produced but may or may not be consuming it. Millet (Pennisetum typhoideum), sorghum (Sorghum vulgare), maize (Zea mays), rice (Oryza sativa) and acha (Digitalis exilis) wereused in its production in decreasing order ofpreference. The grains were used singly or combined;sorghum/millet was the most common combination in aratio of 1:2 (w/w). Steeping was done in ordinary water for 12–72 h, depending on the grain type, in localclay pots, plastic buckets, calabashes or basins or5–7 h in warm water (60–70 ^°C). The grainswere dry or wet milled with or without spices such asginger, red pepper, black pepper, clove and garlic.Other ingredients introduced included: sweet potatoes,malted rice, malted sorghum and Cadaba farinosacrude extract. Both dry and wet milling was done withgrinding mills, mill stones or mortar and pestle,depending on locality. The product was then cookedinto a thin free flowing gruel. The various types ofkunu were: Kunun zaki, Kunun gyada, Kunun akamu, Kununtsamiya, Kunun baule, Kunun jiko, Amshau and Kunungayamba. Kunun zaki was the most commonly consumed. Production and consumption cut across all socialclasses of the society.     

Long-term frozen storage of wheat bread and dough – Effect of time,temperature and fibre on sensory quality,microstructure and state of water

The objective of this study was to determine effect of storage time, storage temperature and addition of fibre on sensory quality, state of water, microstructure and texture of bread and dough.     

Effect of genotype, environment and agronomic management on β-glucan concentration of naked barley grain intended for health food use

(1,3:1,4)-β-d-Glucan is an important bioactive that contributes to the ability of barley foods to help prevent type-2 diabetes. Realisation of these benefits requires understanding of genotype and environment effects on β-glucan concentration and how this variation affects biological activity of barley foods. Field experiments showed genetic variation in β-glucan concentration (3.0-7.0 g/100 g DM), but also considerable variation between environments. β-Glucan concentrations were lower in the wet summer of 2007 than 2006 or 2009; and slightly less in the dry summer of 2006 than 2009. β-Glucan was not diluted by higher grain yields. The role of β-glucan as an assimilate buffer adds complexity to interpreting the effects of environment during grain filling. Autumn sowing and fungicide increased the duration of grain filling, decreased β-glucan concentration but increased environmental stability; possibly due to lower demand for assimilate buffering. Lodging and foliar disease decreased β-glucan concentration, by decreasing assimilate supply leading to remobilisation of carbohydrate from β-glucan, so that fungicide increased β-glucan in some disease-susceptible accessions. Sequential harvesting starting at GS 91 suggested an optimum harvest window for maximum β-glucan concentration. The variability in β-glucan reported here between genotypes and environments was sufficient to affect control of post-prandial blood glucose in healthy volunteers.     

Triticale extrudates – Changes of macrostructure,mechanical properties and molecular water dynamics during hydration

The effect of hydration (in the range of aw 0.981–0.090) on changes of macroscopic and mechanical features of triticale snacks produced in different conditions (feed moisture - 16 and 20%; extrusion temperature - 135 and 175 °C) was analysed. Changes of snacks depended both on the hydration level and the extrusion process conditions.As a result of storage at the highest hydration level (aw = 0.981) contraction of snacks was observed. The shrinkage was more pronounced in case of extrudates obtained from raw material containing 16% of water regardless of the extrusion temperature. The hardness of extrudates depended both on the feed moisture and hydration. Samples obtained from the raw material containing 20% moisture were harder than those prepared at the feed moisture of 16%. Based on the results of molecular dynamics study by low field NMR technique, a model of hydration was developed and critical hydration value of extruded snacks was calculated. Higher values of the critical hydration were obtained for snacks extruded at temperature 135 °C than for those obtained at 175 °C. The feed moisture level affected critical hydration values to a lesser extent. Obtained results suggest that the state of water in extrudates depends on extrusion process conditions.     

Endogenous redox agents and enzymes that affect protein network formation during breadmaking – A review

During breadmaking, wheat gluten proteins form a continuous network which is stabilized by disulfide bonds and modified by thiol/disulfide interchange reactions. This gluten network results in visco-elastic dough that holds together the other dough components and assists in retaining carbon dioxide. Wheat flour contains several components, enzyme co-factors and enzymes which can affect the formation and properties of the gluten network and, hence, the dough and bread characteristics. We present a brief overview of our current knowledge of the fate of gluten proteins during breadmaking, and how they are affected by endogenous wheat components (e.g. glutathione, cysteine and NAD(P)(H)) and enzyme systems (e.g. tyrosinase, peroxidase, the NADP-dependent thioredoxin and glutathione enzyme systems, protein disulfide isomerase, lipoxygenase, catalase and dehydrogenases).     

St. John’s Wort Herbal Teas – Biological Potential and Chemometric Approach to Quality Control

Plant Foods for Human Nutrition - St. John’s wort has been used for centuries in traditional medicine of many cultures, and nowadays it is well-known as a clinically important antidepressant...