5%唑啉草酯EC防除大麦田中禾本科杂草药效研究

5%唑啉草酯EC是目前防除大麦田中禾本科杂草十分优秀的茎叶除草剂,冬前制剂用1 200 g/hm2,施药后30 d它对禾本科杂草的株防效可达72.99%,药后120 d它对禾本科杂草的株防效可达91.92%,鲜重防效可达94.89%,明显高于同期用50%异丙隆制剂1 875 g/hm2的株防效和鲜重防效;春季制剂用5%唑啉草酯EC 1 500 g/hm2,施药后30 d它对禾本科杂草的株防效可达82.18%,药后60 d它对禾本科杂草的株防效可达96.26%,鲜重防效可达97.61%,同样明显高于同期用50%异丙隆3 750g/hm2的制剂株防效和鲜重防效.     

百农思对稻田玉米杂草的防除效果

为防除稻田玉米杂草,在湖南省浏阳沙市镇进行了百农思等除草剂防除稻田玉米杂草试验.用百农思等芽前除草剂,在玉米播种后1d按推荐剂量喷雾,每公顷喷药液900kg,施药后第20d和第40d调查各处理的除草效果.结合产量性状,按"意见集中评分模糊决策原理”的方法评价除草效果,结果表明,以施用百农思180g/hm2的防除效果最好,药后40d对稻田玉米杂草的株防效和鲜重防效达80.69%和98.60%;其次为百农思150g/hm2+乙草胺1200mL/hm2混用,药后40d的株防效和鲜重防效78.62%和93.89%.百农思对玉米安全.     

15%麦极对小麦的安全性及防除禾本科杂草药效研究

15%麦极可湿性粉剂是目前防除小麦田中禾本科杂草十分理想的茎叶处理剂,冬前每公顷施用300 g,施药后30 d,它对小麦田中禾本科杂草的株防效可达82.00%,药后90 d,它对小麦田中禾本科杂草的株防效可达92.21%、鲜重防效可达95.86%,高于用900 m l/hm216.9%骠马的同期株防效80.38%、鲜重防效86.33%,并且它对小麦田中禾本科杂草除草速度明显比每公顷用750 m l/hm26.9%骠马除草速度快。     

6%精喹·嗪酸乳油防除花生田杂草

田间试验结果表明,6%精喹.嗪酸乳油作茎叶处理对马唐、牛筋草、稗草、反枝苋、藜等杂草均有较好的除草效果。推荐应用剂量为有效量45~54 g/hm2(商品量750~900 mL/hm2),药后20 d对杂草的鲜重防效在95%以上。在推荐剂量范围内对花生安全,一次施药即能有效防除花生田全生育期的杂草,除草效果好。     

50％吡嘧·二氯喹啉酸WP防除水稻田杂草效果研究

50％吡嘧·二氯喹啉酸WP是目前防除移栽水稻田中一年生杂草十分优秀的茎叶除草剂，制剂用600g／hm2，施药后15d它对一年生杂草的株防效可达92．26％，施药后30d它对一年生杂草的株防效可达92．03％，施药后45d它对一年生杂草的株防效可达91．85％，鲜重防效可达93．28％，比同期用10％吡嘧磺隆WP300g/hm2的株防效分别高12．20％、13．00％、12．80％，鲜重防效高12．75％；比同期用50％二氯喹啉酸WP600g/hm2的株防效分别高59．89％、60．68％、61．83％，鲜重防效高57．47％。     

不同除草剂防除稻田杂草试验

通过对不同药剂防除稻田杂草试验效果研究,结果表明,施药剂的各处理均对水稻安全,并且对杂草均有一定的防除效果,防效为92%～100%。综合分析,于插秧前5～7 d水整地后施入50%瑞飞特70 ml/667 m2,防效最好,并且节约成本,可推广应用。     

60%新马歇特EC防除旱直播稻田杂草药效研究

试验研究结果表明:60%新马歇特EC是当前防除盐城市旱直播稻田中禾本科杂草、阔叶杂草较为理想的除草剂,用60%新马歇特EC 1 800 ml/hm2+10%苄嘧磺隆WP 450 g/hm2施药后30 d,它对旱直播稻田中禾本科杂草、阔叶杂草防效分别为95.71%、98.03%;用60%新马歇特EC 1 800 ml/hm2+10%吡嘧磺隆WP 300 g/hm2施药后30 d,它对旱直播稻田中禾本科杂草、阔叶杂草防效分别为98.30%、98.69%。     

35%丁噁乳油防除夏花生田间杂草效果研究

为明确35%丁噁乳油对夏花生田杂草的防除效果及对花生的安全性和增产效应,采用土壤封闭喷雾法进行了田间试验研究。结果表明,35%丁噁乳油850.0~1312.5g.a.i/hm2对花生田牛筋草、马唐草、稗草、狗尾草等一年生禾本科杂草及阔叶草苋、马齿苋有较好的防除效果。药后40d,总株防效为85.34%~93.51%,鲜重防效为95.93%~97.76%;对花生安全性较好,增产率为2.53%。     

嘧啶肟草醚防除直播稻田杂草试验

2012年进行了嘧啶肟草醚防除直播稻田杂草试验。药后35 d调查结果表明,嘧啶肟草醚对鳢肠防除效果达100%,对千金子株防效、鲜重防效均在60%以下。用药区稻苗表现瘦、黄、矮,叶片出现铁锈斑与出叶慢等药害症状,于施药15 d后开始转绿。施药35 d后稻苗已经全部恢复生长。     

济宁市区夏播大豆田杂草的发生与防除研究

研究结果表明,济宁市夏播大豆田杂草有8科20种,优势种群为马唐和醴肠。田间有二个出草高峰,一峰在大豆播种后的5~15 d,二峰在播种后的40~45 d。茎叶处理方法防除禾本科和阔叶混生的大豆田杂草,以5%盖草双单1 500 ml/hm2为最好,总株防效和鲜重防效均在86%以上。以禾本科杂草为主的大豆田,以8.8%精喹禾灵600 ml/hm2防效最好,株防效在83%以上。以阔叶杂草为主的大豆田,24%克阔乐450 ml/hm2防效最好,株防效在82%以上。     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

Evolutionary aspects of the trade-off between seed size and number in crops

Whereas the concept that availability of resources drives seed production is sound in principle, it is incomplete as there are many solutions to the allocation of resources that derive from the trade-off between number and size. This paper examines evolutionary aspects of this trade-off in annual grain crops. The analysis is centred on the working hypotheses that, for a given species and environment, allocation of resources to reproduction involves (H1) high plasticity in seed number, which allows for variable resource availability, and (H2) a relatively narrow range of seed size that results from evolutionary and agronomic selection. Comparisons between crops and fish are used to highlight common evolutionary elements in taxa where parents provide little or no care to their offspring, with the consequence that both number and early survival of offspring, hence fitness of parents, are partially related to embryo size and reserves.

The plasticity of seed number in relation to availability of resources is analysed against the established relationship between offspring number and parent growth rate during critical stages. The notion that seed size is under stabilising selection is analysed against three conditions: (1) mean seed size is conservative for a given species and environment, (2) seed size affects fitness, and (3) seed size is heritable. Databases from published papers were compiled to analyse the relative variability of seed size and number, and the heritability of seed size. Evidence for and against the link between seed size and parental fitness is revised using the Smith–Fretwell model as framework (Am. Nat., 108, 499–506).

The proposal of high plasticity of seed number and narrow variability of seed size resulting from stabilising natural selection is generally consistent with evolutionary and genetic considerations. Agronomic selection may have reinforced natural selection leading to relatively narrow seed size in species such as wheat and soybean, where cultivated types retained high plasticity for seed number. In contrast, selection for one or few inflorescences in crops like sunflower and maize may have morphologically reduced seed number plasticity and increased variability of seed size and its responsiveness to resource availability in relation to their wild ancestors.     

Citrus Flavonoids in Fruit and Traditional Chinese Medicinal Food Ingredients in China

Flavonoids-enriched tissues of citrus such as peel, immature fruit and flower are consumed as culinary seasonings, tea ingredients in China for centuries. This HPLC quantitative study on the five citrus flavonoids, naringin, hesperidin, neohesperidin, sinensetin and nobiletin on a wide range of Chinese citrus fruits and several Traditional Chinese Medicinal food ingredients in East China, revealed a great diversity in flavonoid composition. Huyou peel (C. paradisi cv. Changshanhuyou) was found to be the best naringin (3.25%) and neohesperidin (2.76%) source; C. aurantium, a major ingredient of several citrus-related TCM, is also a suitable source of naringin and neohesperidin, and a good juice source for flavanone glycosides; the peel of Wenzhoumiju (C. unshiu) is one of the richest local species in hesperidin (up to 6.25%); Zaoju (C. subcompressa) has the highest content of nobiletin (0.59%), a polymethoxylated flavone. LC-ES-MS analysis of Zanthoxylum genus for flavonoids revealed for the first time the presence of significant amounts (0.74%) of hesperidin in the root of Liangmianzhen (Z. nitidum (Roxb.) DC), a relative of Sichuan pepper, which is a spice widely used in China.     

Effect of a continuous hot water treatment of potato tubers on seed-borne fungal pathogens

Summary The viability of five pathogens was decreased by treatment with hot water when tested in vitro.Polyscytalum pustulans was most sensitive andRhizoctonia solani least sensitive. Potato tubers were exposed to 55°C for 5 min in a commercial continuous hot water treatment plant using naturally contaminated seed tubers and tubers which had been inoculated by dipping in comminuted cultures. The frequency of eyes colonised byP. pustulans, Helminthosporium solani, andR. solani was reduced to virtually zero and the effect persisted on tubers subsequently stored at 4°C and at 15°C for up to 16 wk. Results withColletotrichum coccodes were inconclusive. Treatment suppressedPenicillium spp. which, however, rapidly recolonised the eyes during storage, leading to higher contamination levels in the treated than in the untreated tubers. With tubers inoculated withPhoma foveata, good control was achieved when the incubation period before treatment was 10 d but not when the period was 42 d.     

Role of Benzoxazinones in Cereals

Summary

Heterocyclic 1,4-benzoxazin-3-ones and related benzox-azolinones are important natural products of the cereal crops maize, wheat and rye. Much research has focused on the role of these compounds as defensive agents against plant diseases and pests. Studies of a wide variety of biological effects on herbivores and nematodes, plant pathogenic fungi and bacteria are reviewed in this article. Phytotoxic activity of the compounds is also considered with respect to allelopathic interaction with higher plants. Recent investigations of molecular aspects of interactions of cyclic hydroxamic acids and related benzoxazo-linones with acceptor organisms have demonstrated different effective detoxification strategies and tolerance mechanisms. This research has greatly advanced our knowledge about the multiple roles that these allelochemicals play in ecological systems.     

Potential of dry fractionation of wheat bran for the development of food ingredients,part I: Influence of ultra-fine grinding

Wheat bran is an undervalued by-product of white flour and has great nutritional potential due to its high content in fibres and bioactive compounds. Micronized bran could be used as a food ingredient to improve the nutritional potential of cereal products, or be used as a starting material for other processes (bioactive compound extraction or bran fractionation). The aim of this work was to find a way to efficiently decrease the particle size of bran. The influence of the grinding temperature (ambient or cryogenic grinding) on the granulometric distribution of particles, their composition, and their microstructure was studied, at lab-scale and pilot-scale. It showed that the intrinsic characteristics of bran (glass transition within intermediate layers at −46 °C) had more influence on its grinding behaviour than the type of grinding device used: the particles size distributions obtained after grinding at lab-scale and pilot-scale were very similar. At both scales, the granulometric curves were narrow for cryogenic grinding, while for ambient grinding they were spread over the whole particle size range. Ultrafine particles were obtained in both ambient and cryogenic conditions. Negative temperatures, by increasing the material’s brittleness, favoured a fast fragmentation of bran: one step of cryogenic grinding allowed a median particle size of nearly 50 μm to be reached, whereas three successive steps of ambient grinding were needed for the same result. On the other hand, ambient temperature favoured the dissociation of the different constituent layers of wheat bran, and produced less composite particles than cryogenic grinding.     

Multiple use of plants: Studies on selenium incorporation in some agricultural species for the production of organic selenium compounds

The technique of spraying plants with inorganic forms of selenium can be employed for phytochemical production of organic selenium compounds. Fractionation of the plant material makes it possible to produce a highly concentrated and well defined selenium supplement with potential use in animal and human nutrition. The fractionation also gives opportunities to combine production of organic selenium compounds with other products, for example plant fibres. Multiple use of plants can contribute to a more efficient utilization of land area (in comparison to monocultures solely adapted to food production). It also gives the opportunity to develop systems suitable for long term fixation of carbon, as long as the plant material is not reoxidised to carbon dioxide. Plant fibres could provide raw material for the production of paper or building materials in combination with the production of organic selenium compounds preferentially accumulated in another fraction of the processed plant.     

Biological factors influencing the transmission of potato leafroll virus by different aphid species

Summary Macrosiphum euphorbiae, collected in the field from potato plants infected with potato leafroll virus (PLRV), transmitted the virus to fewer potato plants in a field trial than did laboratory-rearedMyzus persicae. In the laboratory,M. persicae was the only efficient vector of PLRV fromPhysalis floridana seedlings, potato sprouts or excised leaves toP. floridana. Two clones ofM. euphorbiae and one clone ofAulacorthum solani transmitted PLRV from infected potato plants toNicotiana clevelandii as effeciently asM. persicae but a clone ofAphis gossypii was an inefficient PLRV vector. An isolate of PLRV, whichM. persicae transmitted inefficiently from potato toN. clevelandii, was also transmitted inefficiently byM. euphorbiae andA. solani.