Residues of pyrethroid treatments,alone or with foliar urea,on tomato

Phytoparasitica - The effect of foliar urea treatments on the persistence of synthetic pyrethroid residues on tomato was studied. Fenvalerate was found to persist more and deltamethrin less than...     

几种除草剂和助剂对苜蓿Medicago sative出苗和生长的影响

在温室条件下研究了几种苗前除草剂单用或混用对苜蓿出苗和生长的影响,以及不同叶龄苜蓿对苗后除草剂的反应及添加助剂对药效的影响。结果表明:咪唑乙烟酸在60~120 g/hm2剂量下,于苗前施用,对苜蓿出苗和幼苗生长都有明显的抑制作用。咪唑乙烟酸(30 g/hm2)与二甲戊灵(495 g/hm2)混用,对苜蓿的药害显著降低。苗后施用除草剂对苜蓿的安全性与叶龄密切相关。咪唑乙烟酸以30~60 g/hm2剂量在苜蓿3叶期施用,对苜蓿安全;在120 g/hm2用量下,对5叶期的苜蓿无明显药害。乳氟禾草灵(130~260 g/hm2)和丙炔氟草胺(75~150 g/hm2) 无论是3叶期还是5叶期施用,对苜蓿幼苗都有严重的药害。与咪唑乙烟酸单用时比较,药液中添加1.0 mL/L 的平平加-15和AM-100及5.0 mL/L的SDP,对苜蓿幼苗生长无明显影响。     

Seed production and subsequent seed germination of Senecio vulgaris (groundsel) grown alone or in autumn-sown crops

Senecio vulgaris is a common weed of agriculture in the UK, but is also of food value to invertebrates and birds. Thus, it may be beneficial to retain it within agricultural ecosystems to enhance overall biodiversity. A less intensive approach to weed management requires a sound understanding of weed population dynamics so as to avoid unacceptable population growth. Experiments were carried out in 2003 and 2004 to assess seed production, and subsequent germination, by S. vulgaris growing alone, in winter wheat, or in winter field beans. Plant and seed samples were collected during May and June. There was a strong allometric relationship between capsule number and plant weight, irrespective of the year or the presence of crop competition. Numbers of seeds/capsule varied slightly from 51 to 66 seeds per capsule. Plants growing alone were estimated to produce 8471 to 12 887 seeds per plant, whilst those in wheat only 923 to 2156. Germination tests in Petri dishes in incubators showed that virtually all seeds were viable and germinated under daily alternating light:dark conditions within 10 days. Seeds in continuous dark germinated less readily, reaching only 30% after 21 days. On the basis of this and other published work, it would appear that the retention of S. vulgaris in arable fields will not pose a major threat to the long-term viability of crop production.     

Control of Galium aparine (cleavers) in winter cereals with mecoprop alone or with ioxynil plus bromoxynil

A series of eleven field experiments over two seasons investigated the control of Galium aparine (cleavers) with mecoprop and a proprietary mixture of ioxynil plus bromoxynil. Applications of mecoprop (2?4 kg a.e. ha^?1) between December and March gave variable results but a mixture of ioxynil + bromoxynil (0?6 kg a.i. ha^?1) and mecoprop improved control up to at least 90%, at most sites. Applications of mecoprop alone in April were most effective and frequently achieved more than 90% control. In May, when the G. aparine plants were very large, it was less successful. The reasons for the environmental effects on performance are discussed. Preliminary examination of the effect of soil temperature on mecoprop activity indicates that the reliability of control increases with increasing temperature (0–12°C). An average of 94% control was achieved when soil temperatures were greater than 6°C. La destruction de Galium aparine (Gaillet) dans les cereales d'hiver avec du mecoprop seul ou avec ioxynil plus bromoxynil     

Antifungal activity of sodium propylparaben alone or in combination with low doses of imazalil against Penicillium decay on citrus fruit

The performance of postharvest treatments with sodium propylparaben (SPP), alone or combined with low doses of the fungicide imazalil (IMZ), against citrus green (GM) and blue (BM) molds was evaluated on several citrus species and cultivars artificially inoculated with Penicillium digitatum and P. italicum, respectively, and incubated at 20 °C or cold-stored at 5 °C. Effectiveness of 100 mM SPP dips at 20 °C for 60 s was higher on oranges than on mandarins, with GM and BM incidence reductions of up to 60–90 % after 7 days at 20 °C. Irrespective of citrus cultivar and storage condition, SPP generally improved the curative action of 25 μl l^?1 IMZ to control Penicillium molds. In additional tests, 100 mM SPP dips at 20 °C for 60 s only prevented GM on ‘Valencia’ oranges inoculated 24 h after treatment when combined with IMZ. It can be concluded that postharvest SPP treatments show promise as an effective alternative to be considered in citrus postharvest disease control programs.     

The effect of single, binary, and tertiary combination of few plant derived molluscicides alone or in combination with synergist on different enzymes in the nervous tissues of the freshwater snail Lymnaea (Radix) acuminata (Lamark)

The effect of single, binary, and tertiary combination of few plant derived molluscicides alone or in combination with synergist on different enzymes (acetylcholinesterase—AChE, lactic dehydrogenase—LDH, and acid/alkaline phosphatase—ACP/ALP in the nervous tissue of the freshwater snail Lymnaea acuminata were studied. Sublethal in vivo 24 h exposure to 40 and 80% of LC₅₀ of Azadirachta indica oil (AI), oleoresin of Zingiber officinale (OL), Cedrus deodara oil (CD), Allium sativum (AS), and Polianthes tuberosa (PT) bulb powder singly, their binary combination of AI + OL, AS + CD, AS + PT, CD + OL, CD + PT, OL + PT, and tertiary combination of these binary combinations with the synergist piperonyl butoxide (PB) or MGK-264 significantly altered the activity of these enzymes. Tertiary combination with PB or MGK was very effective. Combination of CD + PT + MGK was more effective against AChE whereas, the combination of CD + OL + PB, CD + AS + PB, and CD + PT + PB were more effective against LDH, ACP, and ALP, respectively.     

Effects of barley yellow dwarf and ryegrass mosaic viruses alone and in combination on the productivity of perennial and Italian ryegrasses

Moderately severe strains of barley yellow dwarf virus (BYDV) and ryegrass mosaic virus (RMV) significantly reduced the heights and yields of perennial ( Lolium perenne ) and Italian (L. multifiorum) ryegrasses. BYDV caused greater reductions in perennial ryegrass than in Italian, whereas the converse was true of RMV. Both viruses together rarely caused greater damage than the most damaging virus on its own. BYDV reduced the aggressiveness of perennial ryegrass more than of Italian, whereas with RMV the converse was true. In mixtures of perennial and Italian ryegrasses, the perennial was suppressed by the Italian when only BYDV was present, the Italian was suppressed by the perennial when only RMV was present, and the status quo was maintained when both viruses were present, even though they reduced the yield of the mixture by over 16%.     

基于AHP法的城市现代化水平综合评析——以鄂尔多斯市为例

城市现代化是现代化在城市这个特定空间地域上的投影,是城市化的进一步延伸,也是城市化发展的高级形态。根据城市现代化的概念与内涵,构建了鄂尔多斯市城市现代化评价指标体系与测度模型;运用AHP法,从经济、社会、人口、市场、科技五个方面构建了评价指标体系;最后对鄂尔多斯市2000-2008年的城市现代化水平进行了综合评析。结果表明:从2000年到2008年,鄂尔多斯市城市现代化综合水平呈上升趋势,但是总体水平仍然较低。     

Unusual or interesting records of plant pathogenic Oomycetes

The following records from the UK are discussed: Peronospora grisea on Hebe gauntlettii (forming oospores), H. elliptica x pimelioides cv. Carl Teschner and H. hulkeana ; Peronospora fragariae on Potentilla recta ; Peronospora hariotii on Buddleia davidii cv. Pink Delight and B. globosa ; Pythium tracheiphilum on Lactuca sativa . The following records from other countries are discussed: Phytophthora erythroseptica var. erythroseptica on Cymbidium sp. in Western Australia; Phytophthora palmivora on Zizyphus jujuba in Taiwan (a new record on this host); Plasmopara halstedii on Arctotis sp. in New Zealand (a new record of this species for Australasia).     

Bacterial leaf streak or black chaff of cereals

The literature related to bacterial leaf streak of cereals, due to various pathovars of Xanthomonas campestris , is confusing and dispersed. This review presents a synthesis of the knowledge that has been accumulated on the disease in cereals since the early reports on barley and wheat. The aim is to present the current status on geographical distribution of the disease, to explain possible confusions in symptoms, and to show the limited quantitative information available on losses and on host/pathogen interactions. Disease etiology and means of control are also reviewed. The objective is to define the present situation of black chaff in wheat, barley and triticale, and to delineate the major research needs in these crops. Difficulties in controlling bacterial leaf streak arise as a result of limited epidemiological knowledge and of the absence of satisfactory seed treatment permitting the eradication of the bacterium. There is an urgent need for a seed certification scheme and for more information on genetic resistance, with a view to limiting outbreaks of this sporadic but devastating disease.     

Induction of pathogenesis-related (b) proteins in Phaseolus vulgaris upon fungal or viral infection or after chemical injury

European Journal of Plant Pathology -     

含嘧啶氧基和一氟甲氧基的吡唑邻甲酰氨基苯甲酰胺的合成及杀虫活性

以取代邻氨基苯甲酸和取代吡啶基吡唑羧酸为原料,合成了10个结构新颖的含嘧啶基和一氟甲氧基的吡唑邻甲酰氨基苯甲酰胺类化合物,其结构通过1H NMR和MS表征。盆栽法试验表明,在500 mg/L 质量浓度下,部分化合物对小菜蛾 Plutella xylostella 和苜蓿蚜 Aphis medicaginis的相对防效达100%。     

Mitochondrial changes during storage of untreated or CIPC-treated potatoes

During storage of potato tubers (Solanum tuberosum L., var. Bintje), important changes appear which affect respiratory control, $\text{ADP}\text{O}$, intensity of O₂ consumption in the presence of different substrates, and NAD⁺ dependence, In mitochondria extracted under strictly similar conditions, from patato tubers stored at 4°C, the respiratory control (RC) maintains a value near 4 for 4 to 5 months. It then declines progressively to low values. At 20°C, a stable RC of 4 can be observed for several months, which then decreases at the end of dormancy. Then, the RC increases sharply; at this stage, $\text{ADP}\text{O}$ are abnormally low, and, some time later, NAD⁺ dependence disappears. Mitochondria treated with 250 μM chlorpropham show a 50% inhibition of the electron transfer with exogenous NADH as substrate. After tuber treatment with 1% chlorpropham, sprouting is inhibited for several months. The activities of mitochondria extracted from such tubers remain unaffected by the treatment. The use of this phenylcarbamate for potato tuber treatment permits obtaining functional mitochondria from tubers after a slightly longer period of storage.     

Synergistic antifungal interactions of zinc or copper with anilazine

Two isolates of Botrytis cinerea and one of Colletotrichum coccodes were used to test for synergistic or antagonistic interactions (a) between pairs of 11 common fungicides and (b) between mixtures of individual fungicides with components of foliar fertilisers. Two screening assays monitored the effects with time of inhibitor combinations on spore germination and subsequent mycelial growth. The combinations that gave positive results for interaction in the screening assays were further investigated by a third quantitative assay, which compared the observed inhibition of mycelial growth with the net inhibition predicted by a non-interaction model. This model assumed that the components of a combination of substances each inhibited the test fungus independently of one another. Only mixtures of anilazine with zinc or copper resulted in appreciable deviation from the predicted behaviour based on a non-interaction model. The inhibition of mycelial growth by combinations of anilazine with Zn²⁺ (inorganic salt or formulated with urea) was consistently greater than predicted for each of three fungi on either of the two test media. Similar effects were observed with Cu²⁺, although the synergism was less marked.