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• The brown rot fungi of fruit crops (Monilinia spp.): II. Important features of their epidemiology (Review paper)

  17-33.

  I. J. Holb

  Views:

  246

  Plant disease epidemiology provides the key to both a better understanding of the nature of a disease and the most effective approach to disease control. Brown rot fungi (Monilinia spp.) cause mainly fruit rot, blossom blight and stem canker which results in considerable yield losses both in the field and in the storage place. In order to provide a better disease control strategy, all aspects of brown rot fungi epidemiology are discribed and discussed in the second part of this review. The general disease cycle of Monilinia fructigena„M. laxa, M. fructicola and Monilia polystroma is described. After such environmental and biological factors are presented which influence the development of hyphae, mycelium, conidia, stroma and apothecial formation. Factors affecting the ability of brown rot fungi to survive are also demonstrated. Then spatio-temporal dynamics of brown rot fungi are discussed. In the last two parts, the epidemiology of brown rot fungi was related to disease warning models and some aspects of disease management.

• Some biological features of cherry leaf spot (Blumeriella jaapii) with special reference to cultivar susceptibility

  91-93.

  I. J. Holb

  Views:

  612

  In this review, some important features of biology are summarised for cherry leaf spot (Blumeriella jaapii). In the first part of the review, the geographical distribution of the pathogen and the causal organism are described. Disease symptoms and disease cycle of cherry leaf spot are also shown. Special attention is given to hosts and then several cherry cultivars.are described in relation to their susceptibility to cherry leaf spot.

• Apple powdery mildew caused by Podosphaera leucotricha: some important features of biology and epidemiology

  45-51.

  I. J. Holb

  Views:

  433

  In this review, some important features of biology and epidemiology are summarised for apple powdery mildew (Podosphaera leucotricha). In the first part of the review, the geographical distribution or the pathogen are discussed, then the morphology and taxonomy of the causal organism are described. Disease symptoms or apple powdery mildew are also shown and then host susceptibility/resistance is discussed in relation to durability of resistance. In the second part of this review, the general disease cycle of powdery mildew on apple are demonstrated and some basic features of powdery mildew epidemiology (such response of the pathogen to temperature, relative humidity, and rain as well as spore production, spore dispersal, diurnal patterns and temporal dynamics of the pathogen/disease) are also given on apple host.

• Apple powdery mildew caused by Podosphaera leucotricha: some aspects of biology

  19-23.

  I. Holb

  Views:

  389

  Apple powdery mildew (Podoshphaera leucorticha) occurs wherever apples are grown. One of the most important fungal disease of apple which causing severe econimic loss on susceptible apple cultivars. Biology of the pathogen is widely investigated all over the world in the past 100 years. In this review, a summary from this enormous research is made for biology of apple powdery mildew in the following aspects: geographical distribution, morphology, taxonomy of the causal agent, symptoms, host susceptibility, resistance durability and disease cycle.

• Brown rot blossom blight of pome and stone fruits: symptom, disease cycle, host resistance, and biological control

  15-21.

  I. J. Holb

  Views:

  901

  In this paper, important features of symptoms, biology and biological disease management are summarised for brown rot blossom blight fungi of pome and stone fruit crops (Monilinia laxa, Monilinia fructicola and Monilinia mali). Firstly, European brown rot caused by Monilinia laxa is discussed highlighting the blossom epidemiology features, then host susceptibility of the most important stone fruit species including several Hungarian and international cultivars. At the end of this chapter, recent biological control possibilities against Monilinia laxa are also included. Secondly, American brown rot caused by Monilinia fructicola is discussed. Symptoms, biological features of blossom blight and host susceptibility of flowers to Monilinia fructicola are demonstrated. Finally, the symptoms and the biology of the least frequent species, Monilinia mali are shown.

• Effect of dry and wet years on primary inoculum source, incubation period and conidial production of Venturia inaequalis

  53-58.

  I. J. Holb

  Views:

  229

  The present study focuses on the characteristics of epidemics caused by the selected model-pathogen, Venturia inaequalis in relation to weather elements, with special respect to the increasing or decreasing effects of the specific weather elements. First, those weather elements are discussed which have a role in the development of scab epidemics. Subsequently, by accepting the thesis that climate change includes also weather extremes, an extremely hot and dry year (2003) and a colder year of higher than average precipitation (2004) were chosen as models. The presented examples verified that the variability of weather elements had had an undoubtable effect on the development of epidemics. The variability of weather elements manifests in the unusual behaviour of the pathogen, resulting in no or extreme disease epidemics. The extremities are well demonstrated by the fact, that in a year of drought an efficient protection can be achieved by considerably less applications than average, while in the next rainy year, the susceptible cultivar cannot be protected effectively even with such a high number of applications as is usual under humid Western-European climate conditions. It can also be noted, that the pathogen has a very good adaptability under unfavourable weather conditions. Consequently, more efficient management strategies should be developed for protection against the effects of extremities. However, it should be emphasized that it is very difficult to adapt to the variability and extremities of weather in the practice, because no long-term, accurate and reliable information is available about the variability of these elements.