Plant protection equipment in glasshouses1

The use of pedestrian equiprnent such as sprayers, blast sprayers and fogging machines in glasshouses of dilferent size is still very common. Hand-held sprayers or those carried by straps on the back or on one shoulder are well known. Fogging machines are in use as pedestrian or stationary equipment. For pedestrian sprayers, the quality of distribution and the accuracy ofdosing depend very much on the qualification of the operator. As to the use of stationary cold fogging, a summary is given of a research programme to investigate various influences on the quality of distribution and recovery. To guarantee reproducible results in distribution quality, the model of the cold-fogging machine has to be adjusted to the size of the glasshouse. In big cold houses, it is important to have sufficient circulation of the airstream. The force of the circulating airstream depends on droplet size and on the size of the glasshouse. Good distribution quality and high recovery rate cannot be achieved at the same time.     

The problem of bacterial canker of hazelnut in Greece caused by Pseudomonas syringae pv. avellanae1

The present situation of the disease in Greece and its main aspects, causal agent, symptomatology, epidemiology and control measures are described. The characteristics differentiating the pathogen from some other Pseudomonas species are also reported.     

Ozonated water electrolytically generated by diamond-coated electrodes controlled phytonematodes in replanted soil

Journal of Plant Diseases and Protection - Phytonematodes cause severe yield losses in horticulture, partly because they are difficult to manage. Compact, energy-efficient generators that...     

Collar rot caused byPhytophthora citrophthora on pear trees in Greece

A severe crown rot of pear trees of cultivar ‘Kondoula’ grafted on quince rootstock was observed in Greece. Isolations from the affected tissues repeatadly yielded aPhytophthora sp. that was determined by morphological and physiological characteristics to beP. citrophthora. The pathogenicity of two of theP. citrophthora isolates was tested by inoculating trunks of 2-year-old pear trees by mycelial agar disks. Thirty-two days after inoculation all inoculated trees were infected. Although the pear isolates could not be differentiated from isolates ofP. palmivora orP. nicotianae based on isozyme profiles of α-esterase or lactate dehydrogenase, RAPD profiles with one selected primer differentiated the pear isolates from the other species and revealed an electrophoretic banding pattern similar to that of aP. citrophthora standard. This is the first report ofP. citrophthora on pear trees in Greece.     

Present problems of meteorological services for plant protection in the Czech Republic1

Agriculture in the Czech Republic and its supporting services have been influenced during the last four decades by: (1) heavy pollution of the environment; (2) structural changes in the agricultural sector, i.e. collectivization in the fifties and privatization in the nineties; (3) global climate changes. Further destruction of the environment must be avoided, and methods of integrated plant protection, including biological methods, must be used whenever possible.     

Olive knot disease in Greece1

Olive knot disease caused by Pseudomonas syringae subsp. savastanoi is widespread all over Greece where olive is grown and its severity varies from heavy in some areas and cultivars to very mild in others. Hypertrophied enlargements (galls or knots) more or less spherical in shape and up to 2.5 cm in diameter develop mostly on shoots, twigs, branches and trunks. Fruit infection, as roughly circular brown spots of 0.5-2.5 mm in diameter, is another form of disease which develops during wet summers. All olive cultivars are equally susceptible to the pathogen. However, the differences in disease distribution and severity observed between cultivars and areas are directly related to the degree of wounding from whatever cause (frost, hailstorm, harvesting injuries), especially when they are accompanied by rainy and wet weather or moist winds. Harvesting by beating the trees with sticks is an important epidemiological factor for disease incidence in Greece. Suggested control measures are summarized.     

Occurrence of a new powdery mildew of greenhouse tomato in Greece, caused by Erysiphe sp.

An epiphytic pathogen causing powdery mildew on greenhouse-grown tomato (Lycopersicon esculentum) appears for the first time in Greece and is identified as belonging to the genus Erysiphe.     

Mycocentrospora cladosporioides on olive in Greece1

Mycocentrospora cladosporioides has been recorded as present and widely distributed on olive fruits and leaves in Greece since 1972. The fungus frequently appears on the lower surface of the older leaves, growing like a dark olivaceous mould. The disease, known as cercosporiosis, sometimes causes severe defoliation. Green and mature olives are occasionally attacked. The severity of fruit infection seems to be related to mild humid weather in the 3 months prior to harvest. Diseased fruits show superficial slightly sunken irregular dry spots often covered by the characteristic fructifications of the fungus. Infection of artificially inoculated detached olives starts with the appearance of slow-growing brown lesions surrounding the lenticels. Cultivars producing large fruits for table use (e.g. Conservolia) are more susceptible. The fungus grows very slowly in culture and forms only a few conidia. Epidemiology and control have been little studied. Copper-based fungicides used for olive scab control are not always effective against cercosporiosis.     

推广植保技术要有市场化观念

近年来,四川省植保系统在探索市场经济环境下如何搞好植保技术推广,不断壮大自身实力方面有了一些收获,其中最重要的就是在市场观念指导下,植保技术的推广注重了创新。1解放思想,观念要创新1)推广植保技术要有市场化的观念。目前我国广大农村,农民既是生产者,也是生产资料和技术服务的消费者,在农业生产中他们最需要的就是病虫防治技术,他们的需求就是市场。但是在“谁服务好就相信谁”的基本消费观支配下,农民有选择服务者的主动权。因此,我们不能再以命令或施与者的身份出现在他们面前,而是作为掌握着各种新技术的“供应商”身份为他们所…     

Plant waste-based composts suppressive to diseases caused by pathogenic Fusarium oxysporum

The suppressive ability of three plant residue-based composts that could serve as components of soilless media for several vegetable crops was tested on four different formae speciales of Fusarium oxysporum: melonis, basilici, radicis-lycopersici and radicis-cucumerinum. The composts were prepared under controlled conditions from a mixture of separated cow manure (SCM) with orange peels (OP), wheat straw (WS), or dried tomato plants that had been removed from the greenhouse after the end of the season (TP). Disease development in melon, tomato and cucumber seedlings growing in the three composts was significantly less than that observed in peat. Plant inoculation was achieved by conidia produced in culture, conidia naturally produced on infected stems and soil inoculum produced by enriching the soil with infected tissues. Pathogen colonization of the roots and stems of infected melon plants grown in TP–SCM and OP–SCM composts was significantly lower than that of peat-grown plants. Sterilization by gamma irradiation reduced the suppressive capability of TP–SCM and OP–SCM composts, whereas it did not affect the disease development and final disease incidence in peat. Tested formae speciales exhibited differing decline rates of the conidia incorporated in the composts, compared with the rate in the peat control, which suggests that different mechanisms may be involved in the suppression of the different pathogens. The present study shows that composts based on plant-waste residues suppress diseases caused by different formae speciales of Fusarium oxysporum.     

加入《国际植物保护公约》后植物保护科研工作面临的挑战

概述我国加入并接受的<国际植物保护公约>1997年修订文本的核心内容,并从有害生物风险分析、检疫技术与方法以及监测与控制能力等方面阐述了我国加入公约后植物保护科研工作面临的机遇和挑战.     

Olive sickle leaf symptoms widespread in Greece1

Symptoms of olive sickle leaf, a disorder of olive considered to be of virus or virus-like etiology, have been observed in Greece since 1980. Surveys at many places in Attiki, Peloponnisos and Makedonia regions showed symptoms in all cases, on cultivars Kalamon, Koroneiki, Manaki and Megaritiki. The frequency of symptom occurrence in individual trees and the intensity of symptoms varied from year to year, and 1981 was the year with the most frequent and strongest expression of the disorder. The proportion of affected shoots per tree usually varies between 5 and 90%.     

神府煤田采煤塌陷引起的生态问题探讨

通过野外定位观测和室内分析,研究了神府煤田风沙区采煤塌陷1-2年后地表颗粒组成、土壤水分和植被群落的动态变化及引发的生态问题.结果表明:非塌陷区(对照)沙丘,地表颗粒组成以细砂和极细砂为主,占整个组成的63.76％,而采煤塌陷1-2年后,颗粒组成以粗砂和中砂为主,占整个组成的65％以上,呈现粗化现象,潜在可风蚀性程度加强;形成的塌陷裂缝和地表破损,增加了土壤蒸发面,导致土壤水分降低,和对照相比,地表层(O-20cm)范围内的土壤水分流失量最大,达151％,中间层(30-70cm)流失139％,深层(70cm以下)流失101％,整个沙丘典型位置的累积土壤水分流失量达392％,且随着剖面深度的增大而减小,直接加剧了沙质土壤的旱化;采煤塌陷引起的塌陷裂缝、地表破损、地表颗粒粗化以及土壤水分的流失等因素,促使植被大量死亡,植被的死亡率加大又直接反作用于塌陷地表,在风的作用下引发严重风蚀.     

Almond protection in relation to good plant protection practice 1

The EPPO programme on‘good plant protection practice’(GPP) is presented and its purpose explained. An EPPO standard on GPP in stonefruits is in preparation, and the elements which will appear in this for almond provide a brief review of the main pests of almond in Mediterranean countries, their importance, and how they can best be controlled and managed.     

Serious fungal and bacterial diseases of almond in Greece 1

The main fungal and bacterial diseases of almond in Greece are reviewed, with particular attention to phytophthora collar rot and verticillium wilt.