智利小植绥螨商品化生产与应用

智利小植绥螨Phytoseiulus persimilis是叶螨的专食性捕食者,国内外用于防治叶螨的重要天敌.本文总结了智利小植绥螨产品研发背景、商品化生产与保存、单独及与其他防治方法的协调应用等,对智利小植绥螨产品的应用技术进行了展望,以推动国内智利小植绥螨产业化得到更大发展.     

Significance of leaf infection by Botrytis cinerea in stem rotting of tomatoes grown in non-heated greenhouses

The most serious symptom of Botrytis cinerea in tomatoes grown in greenhouses is stem rotting. Lesions on the stem may result from direct infection or from progression of the rot along infected leaves, until infection approaches the stem. In a set of experiments conducted in commercial greenhouses, an experimental greenhouse and growth chambers, the significance of the two types of stem infections was studied. In non-heated greenhouses most of the stem lesions originated from progression of the pathogen along infected petioles. The rate at which B. cinerea had progressed on infected petioles was 0.3–0.5 cm/day, an average of ca. 6 weeks was needed for a leaf infection to approach the stem. Application of Trichoderma harzianum T39 extended this time by 1–2 weeks and application of chemical fungicides by 3 weeks. Influence of the environment on the progression of B. cinerea along infected petioles was then determined. Within range of 5–30 °C, the higher the temperature, the more rapid was the rate of disease progression. The fungus progressed more rapidly on tomato petioles incubated at high vapour pressure deficit (VPD) rather than at low VPD. The source-sink relationship of the plant governed the rate of B. cinerea progression along the petioles as well: it was more rapid when the source was restricted (by shading) and slower when the sink was restricted (by removal of flowers and small fruits). The possibility that sanitation of infected leaflets would reduce the incidence of stem rotting was examined in two experiments. In plots not treated with a fungicide, the sanitation treatment substantially decreased the incidence of stem lesions and this treatment was as effective as weekly application of chemical fungicides.     

香港有机高尔夫球场的草坪管理研究实施

OGC启德高尔夫球场为香港首个有机高尔夫球场,本文提出了有机高尔夫球场的管理标准,并以有机农业方式作出高尔夫球场草坪的水肥等栽培管理及病虫草害的综合生态防治方法,为今后有机高尔夫球场的发展提供参考。     

Deterrence of oviposition of adult Ostrinia nubilalis Hubner (Lepidoptera: Pyralidae) by a natural enemy food supplement Envirofeast on maize in France

Oviposition deterrent activity of a natural enemy food supplement, Envirofeast, against Ostrinia nubilalis Hubner females was studied in choice and no-choice tests under laboratory conditions. Maize plants treated with Envirofeast at 25-40 g a.i./l had significantly fewer egg masses per leaf and eggs per egg mass laid on them compared with the untreated control plants in both choice and no-choice tests. However, maize plants treated with Envirofeast concentrations of 10-20 g a.i./l did not significantly deter the insect's oviposition. The optimum rate at which Envirofeast could deter oviposition was 25 g a.i./l. Increasing the rate of Envirofeast application from 25 g to 40 g a.i./l did not significantly increase its oviposition deterrent activity against O. nubilalis. However, reducing the rate from 25 to 20 g a.i./l resulted in a significant reduction in the oviposition deterrent activity of Envirofeast. The egg masses laid by O. nubilalis on Envirofeast treated plants were essentially (80%) located on the lower leaf surfaces in contrast to untreated (control) plants where only 40-60% of the egg masses were deposited on the lower leaf surfaces. The egg masses on the Envirofeast-treated plants were found at sites which did not receive sprays, indicating the importance of good spray coverage when the product is used in the field. The study has demonstrated the oviposition deterrent activity of Envirofeast against O. nubilalis on maize and this indicates that Envirofeast may have the potential to be integrated into programmes to assist in the control of O. nubilalis on maize.     

TEAM Leafy Spurge: An Areawide Pest Management Program

The Ecological Areawide Management (TEAM) Leafy Spurge project is a United States Department of Agriculture and Agricultural Research Service (USDA–ARS) regional, Integrated Pest Management (IPM) program focused on the Little Missouri River drainage in the states of North and South Dakota, Montana, and Wyoming, U.S.A. TEAM Leafy Spurge project represents the first large-scale, systematic study and demonstration of weed management alternatives under USDA–ARS's Areawide Pest Management Program. The other three projects previously approved under the program targeted insect pests. TEAM Leafy Spurge's primary goal has been to demonstrate the use of ecologically based IPM strategies to achieve effective, affordable leafy spurge control. TEAM Leafy Spurge is co-chaired and overseen by the USDA–ARS in cooperation with the USDA–Animal and Plant Health Inspection Service. Both agencies have many years of experience in research and implementation of leafy spurge control tactics as well as valuable contacts and resources. Together those federal partners make a powerful team to address the leafy spurge problem on a multi-state basis. Additional federal agencies participating in TEAM Leafy Spurge include: Bureau of Land Management, U.S. Forest Service, National Park Service, Bureau of Indian Affairs, Bureau of Reclamation, and U.S. Geological Service. State partners include: state departments of agriculture and other state agencies, Cooperative Extension Services, land grant universities, and county weed managers, while private sector representatives include landowners and ranchers. A non-partisan ad hoc committee consisting of state and federal researchers, land managers, representatives from local, state, and federal entities, and private landowners/ranchers provides guidance and helps to ensure the quality and applicability of the program. The extensive partnerships are of particular importance because they help to ensure continued dissemination of information past the limited life span of TEAM Leafy Spurge, which is set to expire in 2003.The five components of TEAM Leafy Spurge research and demonstration project are: (1) Program management; (2) Operations; (3) Assessment; (4) Supporting research, and (5) Technology transfer. As of this writing, the bulk of the research work has been completed and now TEAM Leafy Spurge is focusing its energies on assessment and technology transfer projects. Where available, brief outlines of research results are included here in addition to discussion of the program's key components, overall structure and general operation.     

Organochlorine pesticide residues - a review of some recent findings

Investigations to determine the optimum timing and placement of a supplementary food spray, Envirofeast® on the abundance of predatory insects on cotton was conducted in irrigated commercial cotton fields at Yarral near Narrabri, New South Wales, Australia, in 1998 v - v 99. Plots treated with the supplementary food product at the four-true leaf stage recorded a significantly higher number of predatory beetles, bugs and lacewings per metre compared with plots treated at two, six and eight-true leaf stages and unsprayed (control) plots. The cumulative total number of predatory beetles, bugs and lacewings recorded throughout the season in both treated and control plots was 23.81 per m. Of this total, plots treated at four true leaf stage recorded the highest (7.15 per v m) (i.e 30.03%), followed by two true leaf (5.81 per m) (24.41%), six true-leaf (4.31 per v m (18.12%), eight true-leaf stage (4.63 per v m) (i.e. 19.44%) and the unsprayed (control) plot recorded the lowest (1.91 per m (8.03%). The number of spiders per metre were not significantly different ( p v > v 0.05) among treatments and the control plots. The number of predators recorded in cotton crops treated with the supplementary food product as a band spray (33 v - v 50% band) or skip row spray (i.e. to every second row) was not significantly different ( p v > v 0.05) from plots where the product was applied as a solid spray to the entire crop (no skip row and/or no banding). Thus, tailoring Envirofeast® treatment in this way will ultimately reduce the quantity of product used, the cost of the product and allow cotton growers to adopt a multiple-use pattern for the product to support integrated pest management programmes in cotton.     

Improved Resistance Management for Durable Disease Control: A Case Study of Phoma Stem Canker of Oilseed Rape (Brassica napus)

Specific resistance loci in plants are generally very efficient in controlling development of pathogen populations. However, because of the strong selection pressure exerted, these resistances are often not durable. The probability of a resistance breakdown in a pathosystem depends on the evolutionary potential of the pathogen which is affected by: (i) the type of resistance (monogenic and/or polygenic), (ii) the type of reproduction of the pathogen (sexual and/or asexual), (iii) the capacity of the pathogen for dispersal, (iv) the resistance deployment strategy (pyramiding of specific resistances, mixture of cultivars, spatio-temporal alternation), (v) the size of the pathogen population, which is affected by control methods and environmental conditions. We propose the concept of Integrated Avirulence Management (IAM) to enhance the durability of specific resistances. IAM involves a strategy to limit the selection pressure exerted on pathogen populations and, at the same time, reduce the size of pathogen populations by combining cultural, physical, biological or chemical methods of control. Several breakdowns of resistance specific to Leptosphaeria maculans, the causal agent of phoma stem canker have occurred in Europe and in Australia. This review paper examines control methods to limit the size of L. maculans populations and discusses how this limitation of population size can enhance the durability of specific resistances. It proposes pathways for the development of a spatially explicit model to define IAM strategies. Simulation results are presented to demonstrate the potential uses of such a model for the oilseed rape/L. maculans pathosystem.