Grass scorch due to pot ale

Grass scorch sometimes occurs when pot ale, a waste product of malt whisky distilling, is used as a liquid fertiliser. Experiments performed on grass turves show that a high concentration of solids in the pot ale, and a large amount of foliage on the sward result in higher amounts of scorch, as determined by visual assessment. Sward yield is independent of the amount of leaf scorch but appears to be linked to the proportion of dead tillers or plants in the sward. It is suggested that leaf scorch itself does not limit yield, but if the scorching compound runs off foliage and acts against roots then tiller or plant death may occur, accompanied by a yield loss. This interpretation may help to explain some conflicting evidence on scorch effects in the literature.     

A further study of the anaerobic biotreatment of malt whisky distillery pot ale using an UASB system

Pot ale from a pilot-scale malt whisky distillery was treated using a mesophilic upflow anaerobic sludge blanket (UASB) digester. Stable operation was observed at organic loading rates (OLRs) of 5.46 kg COD/m3 day or less when the pot ale was diluted with tap water. Digester failure occurred when undiluted pot ale was used, even though OLR was less than 5 kg COD/m3 day. Overall performance was worse than that observed previously when UASB digesters were used to treat pot ale from a different source supplemented with trace elements. A substantial proportion of effluent chemical oxygen demand (COD) was present as volatile fatty acids (VFA), particularly during periods of reactor stress, indicating that overall performance was limited by the rate of VFA conversion. Wastewater alkalinity rose during digestion. The sludge which developed in the reactor was flocculent but did not form compact granules.     

The application of genetic engineering to oilseed crops

Increasing attention is being given to the prospects for the genetic engineering of oilseed crops, both in the industrial and academic sectors. The process of creating genetically stable new crops with desirable vegetable oil composition and content is necessarily complex. The modification of seed storage lipids appears to be feasible and there exists a broad knowledge base on lipid biosynthetic enzymes, but applied research and product development will depend on gaining a better understanding of the biochemical bases of lipid biosynthesis.     

Coastal lowland vegetation of eastern Saudi Arabia

This study assesses the plant communities and environmental factors that govern species richness and distribution in the coastal lowlands of eastern Saudi Arabia using TWINSPAN, DCA and regression analyses. Thirty-four vegetation groups were identified, some of these occur in only one habitat: Juncus rigidus and Aeluropus lagopoides-Phragmites australis in the high saline flats, Plantago boissieri-Savignya parviflora, Panicum turgidum-Plantago boissieri-Moltkiopsis ciliata and Panicum turgidum-Haloxylon salicornicum in the non-saline flats, and Bassia eriophora-Launaea mucronata in the depressions between dunes. Some other groups are represented in at least four out of six studied habitats: Zygophyllum qatarense-Launaea capitata-Plantago boissieri, Zygophyllum qatarense-Plantago boissieri and Haloxylon salicornicum-Zygophyllum qatarense. Among 20 examined soil and community variables, regression analysis indicates that only six are influential in the stand ordination process (K, lime, sulphates, pH, plant cover and species richness). Some human impacts (e.g. grazing and cutting intensities) also play an important role. The nature of soil surface and salinity are the main factors that affect the species richness. This revised version was published online in November 2006 with corrections to the Cover Date.     

Effect of distillery effluent on seed germination in some vegetable crops

A laboratory experiment was conducted to study the effect of different concentrations (0%, 5%, 10%, 15%, 20%, 25%, 50%, 75% and 100%) of distillery effluent (raw spent wash) on seed germination (%), speed of germination, peak value and germination value in some vegetable crops: tomato, chilli, bottle gourd, cucumber and onion. The distillery effluent did not show any inhibitory effect on seed germination at low concentration except in tomato, but in onion the germination was significantly higher (84%) at 10% concentration as against 63% in the control. Irrespective of the crop species, at highest concentrations (75% and 100%), complete failure of germination was observed. The speed of germination, peak value and germination value also followed a similar trend. We found that a concentration of 5% was critical for seed germination in tomato and bottle gourd, and 25% in the rest of the crops. Based on the tolerance to distillery effluent, the crops studied have been arranged in the following order: cucumber > chilli > onion > bottle gourd > tomato. We conclude that the effect of the distillery effluent is crop-specific and due care should be taken before using the distillery effluent for pre-sowing irrigation purposes.     

Models of vegetation dynamics in semi-arid vegetation: Application to lowland Central Otago, New Zealand

Predictions from three conceptual models of the dynamics of semi-arid vegetation (Clementsian succession, alternative stable states and annuation/pulse phenomena) are used to review the available evidence on changes in the vegetation of semi- arid lowland Central Otago, New Zealand. Evidence is presented from Central Otago that corresponds with Clementsian succession and with annuation/pulse phenomena, although there is so far no formal evidence of alternative stable states. A declining- productivity model, which combines aspects of the other models, is also shown to fit the process of vegetation change in vegetation dynamics in Central Otago are insufficient for the employment of management frameworks such as degradation gradient assessment and the state-and-transition model.     

Environmental conditions and fen vegetation in three lowland mires

The abiotic conditions and fen vegetation in three lowland mires were analysed. Two of these mires are in the Netherlands. They have deteriorated considerably as a result of human pressure. One mire complex is in Poland. Its hydrology is almost undisturbed. The variation in the water composition in the fens was associated with the variation in the amount of regional groundwater discharge originating from the uplands, and to a lesser extent by the infiltration of polluted water pumped into the fens.The 26 vegetation types ranged from poor fen to eutrophic reedland. Most types were typical for only one region.There were clear differences between the three regions. Both the species composition and the water quality for the vegetation types indicated that the fens in the Vecht river plain are eutrophicated, whereas the fens in Northwestern Overijssel suffer from acidification. The Biebrza valley fens are well developed and are mainly fed by fresh calcareous groundwater.Stepwise logistic regression performed on 28 fen species revealed that the hydrochemical variables explained only a part of the variance: the regional variable area explained a considerable amount of the variance for most species. In 27% of the cases it was possible to fit an optimum curve for the species response to relevant hydrochemical variables. Monotonic curves could be fitted in 64% of the cases; mostly they described the response to variables in a way that is supported by ecological literature. It was concluded that the dataset should be constructed differently to enable the calculation of generally applicable standards.     

Exploratory pot experiments on sensitiveness of different crops to sodium: D. Barley

Summary The effect of sodium on barley has been investigated by means of three pot experiments, of which one was on a humic sandy soil and two on an artificial soil complex (dusarit/quartz-sand mixture).In two of these experiments the effect of sodium — as nitrate of soda — was studied by comparison with calcium nitrate. At low potassium levels sodium was found to excercise a positive effect, but with an ample supply of potassium no differences between the effects of the two nitrate fertilizers were observed.In the third experiment a wide variation in the potassium and sodium levels was introduced by the application of these elements adsorbed to dusarit, all treatments receiving nitrogen in the form of calcium nitrate. Little influence was exercised by the total level of monovalent ions (10, 20 and 40 per cent respectively, of the adsorbed bases). Three-quarters, or possibly seven-eights of the potassium was found to be replaceable by sodium without causing significant changes in the yields of grain and straw.From a survey of the available literature it cannot yet be concluded whether the importance of sodium for barley is limited to a beneficial effect resulting from its mere replacement of potassium, when too little of the latter is available, or whether this importance may be regarded as essential in the sense that sodium has a yield-increasing effect, even in the presence of a sufficiency of potassium.     

Exploratory pot experiments on sensitiveness of different crops to sodium: A. Spinach

Summary In orientating pot trials, carried out partly on soil and partly on an artificial soil-mixture, spinach showed a pronounced ability to take up sodium when dressed with sodium nitrate. The crop benefited much by this type of fertilizer both in yield and outward appearance, as compared with controls receiving calcium nitrate.In spinach sodium can replace potassium to a large extent, but it appears that, when receiving an equal supply of sodium and potassium, this plant prefers potassium. The use of sodium, supplied as a secondary constituent of nitrate fertilizers, is found to have economic importance, because it reduces the plant's need of potassium and improves the yields, even in presence of adequate potassium.In pot experiments with soil the dressing of potassium chloride in combination with Chilean nitrate gave negative results. Chilean nitrate alone, however, produced the highest yields of the series. Combined with nitrate of lime, potassium chloride initially depressed the growth, but showed in the end a slight increase of yield. As the water supplying power of this soil was more or less deficient, it is deemed possible that the negative effect of potassium chloride is due to the action of salt-concentration.It is pointed out that the normally grown spinach from the market-gardening centres destined for consumption may contain very high contents of potassium.These experiments were commenced at the Laboratory for Agricultural Chemistry of the Agricultural College at Wageningen, in concert with Prof. Ir. J. Hudig, Director of the Institute. The experiments could not be finished there owing to interference of war conditions.     

Exploratory pot experiments on sensitiveness of different crops to sodium: C. flax

Summary In three pot experiments the effect of sodium on the development of flax and its fibre quality was investigated. Sodium, applied either in the nitrate form or as dusarit in an artificial soil complex, stimulated the vegetative development, even in the presence of an ample K-supply. It also had a favourable effect on the quality of the fibre, which was greatest when 6 percent of the exchangeable bases were in form of sodium but gradually decreased at higher percentages. Overdosage of sodium, especially in combination with high potassium, induced a condition of calcium deficiency as diagnosed by the drooping of the heads (wilting of the apex), and resulted in lower grain yields.     

Exploratory pot experiments on sensitiveness of different crops to sodium: B. Oats

Summary Two pot experiments with oats are described: 1. on an artificial soil complex (sand-dusarit mixture) and 2. on a humic sandy soil, in which the Na effect of nitrate of soda was studied by comparison with calcium nitrate. On the Na-free sand-dusarit mixture a positive Na effect on grain and straw was obtained at all K levels. On the other hand, the Na effect in the soil experiment was confined to the pots without K dressing. The soil itself however, had an appreciable K content and a high Na content.A further study of the literature on pot experiments with oats leads to the conclusion that the Na effect was incorrectly interpreted in the past as a K-replacing effect, whereas the results point mostly to an independent function of Na by itself (positive yield effects in the presence of sufficient potassium). Out of 12 available examples, only 3 turn out to be in favour of a mere K-replacing action. Moreover, 2 of them cannot be called conclusive, because of unmistakable presence of fairly large amounts of Na in the growing medium.     

Climate changes and virgin vegetation dynamics in the Northern Caspian lowland

A wavy trend toward increasing vegetation biomass in desert, semidesert, and steppe communities growing on solonetzic soils was discovered in the Northern Caspian region over a 60-year observation period (1952–2013). The trend is caused by warming during winter months (due to redistribution of soil moisture) and the improvement of hydrothermal conditions in spring months (the period of most active plant vegetation).     

Invertebrates and vegetation of field margins adjacent to crops subject to contrasting herbicide regimes in the Farm Scale Evaluations of genetically modified herbicide-tolerant crops

The effects of management of genetically modified herbicide-tolerant (GMHT) crops on adjacent field margins were assessed for 59 maize, 66 beet and 67 spring oilseed rape sites. Fields were split into halves, one being sown with a GMHT crop and the other with the equivalent conventional non-GMHT crop. Margin vegetation was recorded in three components of the field margins. Most differences were in the tilled area, with fewer smaller effects mirroring them in the verge and boundary. In spring oilseed rape fields, the cover, flowering and seeding of plants were 25%, 44% and 39% lower, respectively, in the GMHT uncropped tilled margins. Similarly, for beet, flowering and seeding were 34% and 39% lower, respectively, in the GMHT margins. For maize, the effect was reversed, with plant cover and flowering 28% and 67% greater, respectively, in the GMHT half. Effects on butterflies mirrored these vegetation effects, with 24% fewer butterflies in margins of GMHT spring oilseed rape. The likely cause is the lower nectar supply in GMHT tilled margins and crop edges. Few large treatment differences were found for bees, gastropods or other invertebrates. Scorching of vegetation by herbicide-spray drift was on average 1.6% on verges beside conventional crops and 3.7% beside GMHT crops, the difference being significant for all three crops.     

基因枪转化技术及其在禾谷类作物遗传转化中的应用

基因枪转化法广泛用于禾谷类作物的遗传转化研究,是目前禾谷类作物遗传转化的有效方法。简要介绍了基困枪转化法的产生与发展、转化的特点以及影响转化频率的主要因素;系统地概述了基因枪法在禾谷类作物遗传转化的应用。     

图位克隆技术在农作物基因分离中的应用与评价

图位克隆(Map-based cloning)作为分离基因的有效方法, 已在小基因组作物的基因分离中得到了广泛应用和发展, 而在具有大量重复DNA序列的大基因组作物中的应用仍存在挑战。基于图位克隆在基因分离中的重要性, 文章就图位克隆技术的基本内容及发展做简要概述, 着重对图位克隆技术在大基因组作物中的应用进行分析和评价, 同时对它今后可能的发展方向进行了讨论, 以期为大基因组作物基因的分离提供借鉴。