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The brown rot fungi of fruit crops (Monilinia spp.): III. Important features of disease management (Review paper)
31-49.Views:292In the third part of this review, important features of disease management are summarised for brown rot fungi of fruit crops (Monilinia fructigena, Monilinia laxa, Monilinia fructicola and Monilia polystroma). Several methods of brown rot disease management practices were collected and interpreted in five main chapters. In these chapters, details are given about the legislative control measures, the cultural, physical, biological and chemical control methods. Chemical control is divided into two parts: pre-harvest and post-harvest chemical control. In addition, host resistance and fungicide resistance statuses are also included in this part of the review. Finally, future aspects of brown rot disease control are discussed.
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Apple powdery mildew caused by Podosphaera leucotricha: some aspects of disease management
29-33.Views:525Apple 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. This review focuses on the control of apple powdery mildew. The first part of the study provides details of novel aspects of non-chemical control approaches, including agronomic measures, mechanical and biological control options as well as essential features of apple cultivar resistance. After this, developments in chemical control options are described sperately for integrated and organic apple orchards.
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Improving the postproduction quality of Rose cut flowers
109-114.Views:120In order to improve the post production quality of cut flowers of Rosa hybrida L. cv. Baroness, the effect of 8-hydroxyquinoline sulfate (8-HQS), silver thiosulfate (STS) and 1-methylcyclopropene ( I-MCP) were investigated. 8-HQS was used at 200 and 400 ppm with or without sucrose at 50 g LI. STS was used at 0.2, and 0.4 mM with or without sucrose at 50 g 1-I. l-MCP was used at 0.3, 0.5 and 0.7 g in-3 for 6h.
The postproduction quality was improved as a result of using any chemical treatment comparing with untreated control. All the treatments of 8-HQS increased the vase life and minimized the percentage of weight loss of rose cut flowers compared to the control. The vase life was lorger when 8-HQS was combined with sucrose. The best treatment of 8-HQS was 400 ppm 8-HQS + 50 g 1-1 sucrose. STS treatment led to prolong the vase life and minimized the percentage of weight loss compared to the control. In addition, the effect was better when sucrose was added to STS. The treatment of STS at 0.4 mM + 50 g 1-1 sucrose was the best one. l -MCP treatment prolonged the vase life and lowered the percentage of weight loss at any level compared with untreated control. The best treatment in this concern was l -MCP at 0.5 g m-3 for 6h. The chlorophyll content (chl.a and chid)) of the leaves for the best treatment of each chemical was higher than the control. The treatment of STS at 0.4 mM + 50 g 1-1 sucrose gave the best results in this respect.
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Chemical communication with volatile semiochemicals in Phyllotreta species (Coleoptera, Chrysomelidae): a minireview
93-100.Views:148Phyllotreta species (Coleoptera, Chrysomelidae, Halticinae) rank among the most important horticultural pests in the Northern Hemisphere. Leaf damage caused by flea beetles upsets the water balance, blocks plant growth and sometimes causes a high level of mortality of seedlings. Several species are known to act as vectors of numerous pathogens as well. Chemical communication plays an important role in the host finding, feeding and oviposition behaviour of flea beetles. In the first phase volatile mustard oils (isothiocyanates and thiocyanates) are released from the host plants through the decomposition of non-volatile glucosinolates (chemicals specific to Cruciferae) by myrosinase, and beetles are attracted to the source of release from a distance. Among the isothiocyanates, allyl isothiocyanate is the longest known and widespread compound utilized in the host-plant location of Phyllotreta species, but some species may have a stronger preference to other isothiocyanates or thiocyanates. The attractive effect of the plant volatiles is enhanced by the emission of a male-produced aggregation pheromone. The presence of such a pheromone was first demonstrated in Phyllotreta cruciferae Goeze. In this species R5R,5aS)-1,1,5,8-tetramethy1-1,2,3,4,5,6,5a-heptahydrobenzo[1,2-a][7]annulene] was found to be the main pheromone component. Significant attraction by the pheromone was recorded only in the presence of ALLYL ITCN. The biological activity of the pheromone compound was connected to the plus (+) chirality. The same component seems to be occurring also in the pheromones of several other Phyllotreta spp. as well, suggesting a wider occurence in the genus. Once attracted by the joint effect of plant volatiles and aggregation pheromone, the presence of the non-volatile glucosinolates in the plant tissues is necessary for continuous feeding. Aggregations of flea beetles on suitable host plants, which result from the joint effects of plant-derived and pheromonal chemical cues detailed above may also be good rendez-vous occasions, increasing the probability of encounters with the opposite sex and mating in the vicinity of the optimal oviposition site. Due to the horticultural importance of Phyllotreta spp., deciphering details of their chemical communication has considerable significance in the development of new methods of integrated control.
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Postharvest features of chrysanthemum cut flowers as affected by different chemicals
127-131.Views:144Cut flowers of Chrysanthemum morifolium RAM cv. Suny Reagan were treated with different concentrations of 8- hydroxyquinoline sulfate (8-HQS), silver thiosulfate (STS) and 1-methylcyclopropene (1-MCP) in order to improve the post production quality. 8-HQS was used at 200 and 400 ppm with or without sucrose at 50 O. STS was used at 0.2, and 0.4 mM with or without sucrose at 50 g/1 1-MCP was used at 0.3, 0.5 and 0.7 g/m3 for 6h.
All the treatments of 8-HQS prolonged the vase life and minimized the percentage of weight loss of chrysanthemum cut flowers compared to the control. The vase life was larger when sucrose not combined with 8-HQS. The best treatment of 8-1-IQS was 400 ppm 8-HQS without sucrose. STS treatment led to prolong the vase life and minimized the percentage of weight loss comparing to the control. In addition, the effect was better when sucroseas was added to STS. The treatment of STS at 0.4 mM + 50 g/I sucrose was the best one. 1-MCP treatment increased the vase life and lowered the percentage of weight loss at any level comparing with untreated control. The best treatment in this concern was 1-MCP at 0.5 g/m3 for 6h. The chlorophyll content (chl.a and chl.b) of the leaves for the best treatment of each chemical was higher than that of the control. The treatment of 1-MCP at 0.5 g/m3 6h gave the best results in this respect.
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Prolonging the vase life of cut Carnation 'GIOKO' by using different chemicals
65-68.Views:175Cut flowers of Dianthus caryophyllus L. cv. GIOKO were treated with different concentrations of sucrose and in combination with 1methylcyclopropene (1-MCP) to compare the effect of these treatments with floral preservative (`Spring') on the longevity of flowers. Distilled water was used for preparing all solutions. The control flowers were held in distilled water. Clorox at 2 mL- I was added to all treatments containing sucrose and it was also applied as a separate treatment. The vase life of cut carnations was significantly prolonged due to the use of chemical treatments, as compared to the untreated control. The longest vase life (18.33 days) was obtained by using 1-MCP 0.5 g m-3 for 6 h treatment. All concentrations of sucrose had a positive effect on flower diameter. The best treatment in this respect was 1 -MCP with 30 gL-I sucrose. 1-MCP treatment significantly increased the chlorophyll content, as compared to the control or the "Spring" treatment. The highest values in this respect were obtained by 1 -MCP treatment alone or with the lowest level of sucrose. The effect of these treatments on the pH of solutions is discussed.
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Seed protectant potential of Mitracarpus villosus and Phyllanthus fraternus extracts on germinative capability of stored food grains
7-10.Views:322Seed storage is an essential post-harvest operation that decides the success of seeds viability and germination in next generation. The study explored Mitracarpus villosus and Phyllanthus fraternus extracts as bio-insecticides seed treatments on stored wheat and green gram seeds viability and germination. M. villosus and P. fraternus plants powder were sequentially extracted with solvents of increasing polarity (Petroleum ether, hexane, ethyl acetate, acetone, chloroform and methanol), concentrated and tested for insecticidal activity by fumigant toxicity. The extract which showed maximum activity, was selected for seed viability and germination test. Five replications each were made for the treatment and the control. The plant extracts strengthen the non-phytotoxic nature of plant products against seed viability and germination. Seeds treated with extracts (50-400 μg seed-1) did not lose their viability as it resulted in successful and normal germination within the range of 90 – 97.67% irrespective of the extracts concentration. While, seeds in control recorded 95.55 and 100% germination which were not significantly different (P>0.05) compared to the treated seeds. Based on findings from the study, potential exploitation of M. villosus and P. fraternus as food grains protectant in insect pest management strategies is recommended for the resource poor farmers. However, further investigations are suggested on biosafety and effects of the extracts on the organoleptic contents of the grains prior to consumption.
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Role of hydrogen peroxide and Pharmaplant-turbo against cucumber powdery mildew fungus under organic and inorganic production
39-44.Views:411Cucumber leaves have been sprayed with a solution of hydrogen peroxide (H202) or Pharmaplant-turbo combined with organic or inorganic fertilizers under plasic house. Under the influence of H202, leaves exhibited resistant against Podoshaera fusca fungus, the causal agent of cucumber powdery mildew. H202 (15 mM) was able to decrease the disease severity from 90.4% to 12% in two experiments conducted in two seasons. Pharmaplant-turbo (Turbo) is new chemical compound and used as an antifungal compound. Turbo in 1 ml/L was able to decrease the disease severity from 90.4% to 11.5% in the both experiments as well. Both of H202 and Turbo were combined with organic treatment (compost + compost tea + seaweed extracts) which showed significant effect against cucumber powdery mildew fungus and strongly suppressed it as compared to control leaves. Organic treatment produced higher vegetative growth characters and greater early and total yields as compared to inorganic treatment, also organic fruits produced the lower nitrate content and the higher ascorbic acid content as compared to inorganic fruits. Our study have indicated that, H202 and Turbo combined with organic fertilizers play a role in the resistance of cucumber against powdery mildew by decreasing the disease severity. We suggest to give more attention to the direct application of H202 in low concentration and Turbo against powdery mildew diseases and other plant diseases.
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Field trials with non-bactericide products to control fire blight in apple orchards
55-60.Views:132Recently, novel strategies and chemical agents for prophylactic protection against the bacterial (Erwinia amylovora) disease fire blight are being sought. Resistance-inducing compounds, such as prohexadione-Ca represent promising alternatives. Prohexadione-Ca is the active ingredient of the bioregulator Regalis, currently being introduced in several European countries and overseas. Another product used in this study was Biomit Plussz, a leaf fertiliser providing harmonic supply of nutrient elements, the complete supply is assumed to improve the tolerance against diseases.
Treatments' effects of both of these products were compared to the effectiveness of treatments with antibiotics repeated twice, three or four times a season.
In the years of 2001 and 2002, the effectiveness of both Regalis and Biomit Plussz in reduction of incidence of shoot blight was similar, or proved to be superior to the check treatments consisting of repeated sprayings of antibiotics. Last year (2003) treatments of streptomycin resulted — although within the same magnitude — in a somewhat better control of shoot blight than sprayings with the other compounds.
As regards severity of blossom blight, inconsistent results were recorded concerning both Regalis and Biomit Plussz.
In general, prohexadione-Ca is less efficient for controlling flower infection by E. amylovora as compared to shoot infections, since successful prophylactic treatments are difficult to carry out early in the season. The highest effectiveness in fire blight management can, therefore, be achieved by using prohexadione-Ca (as preventive protection) in combination with streptomycin or other suitable antibiotics (as curative protection).
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Efficacy of ethrel (2-chloroethyl phosphonic acid) as a chemical hybridizing agent in red pepper (Capsicum annuum L. var. Pusa jwala)
41-44Views:163A field experiment was conducted during 2003-2004 and 2004-2005 to study the effect of foliar sprays of ethrel or ethephon (2- chloroethyl phosphonic acid) on pollen sterility and yield parameters in Capsicum annuum var. Pusa jwala. Effect of treatments was also studied in F1 hybrids raised from treated male sterile plants crossed with the control plants. Plants sprayed with 0.1, 0.2 and 0.3% (v/v) ethrel exhibited 93.1-100% pollen sterility. This was associated with significant reduction in yield parameters (number of flowers, fruits/plant, fruit size, number of seeds/fruit and total yield/plant). However, the plants sprayed only once with 0.1% ethrel at pre-meiotic stage showed 93.1% pollen sterility without any significant reduction in yield parameter. The F1 hybrids obtained by crossing the 100% male sterile treated plants with the pollen of untreated (control) plants exhibited only insignificant reduction in the number of flowers/ plant, fruits/plant, fruit size, number of seeds/fruit and total yield/plant. However, these parameters in F1 hybrids were significantly higher over the treated plants.
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Selectivity of the oriental fruit moth sex pheromone trap in peach and apricot orchards
17-20.Views:168One of the most important pests of the stone fruit orchards is the oriental fruit moth (Grapholitha 1110/esta B.). Chemical control targeted against the young larvae is the most effective way of protection. so the ti ming of treatments has to be based on the observation of emergence. Emergence may be monitored with sex pheromone traps. It is already known from former publications, that the traps for oriental fruit moth are also effective in the case of the plum moth (Grapholitha f1111ebra11a Tr.), which external morphology is very similar to the oriental fruit moth. As the emergence of the oriental fruit moth in peach and apricot orchards has not been observed in detaib in Hungary, we started a s1Udy in this field. Our aim was to measure the selectivity of the sex pheromone traps. On the basis of examining more than 5000 males caught and the investigation of male genital ia. it could be established that the pheromone traps. Csalomon and Deltastop, for oriental fruit moth, caught the plum moth in the same ratio. The ratio of the oriental fruit moth and the plum moth trapped in the peach orchards was I: I . while in the apricot orchards the number of the caught plum moth males was seven times as many as that of the oriental fruit moths. Consequently, it can be established that data based on oriental fruit moth trap catches can not be used without additional investigations of genitalia for the prediction of larval hatch. The selectivity of the plum moth trap. used as a control. was acceptable in both orchards.
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Extending the vase life of Solidago canadensis cut flowers by using different chemical treatments
83-86.Views:182In order to increase the vase life as well as quality of leaves of goldenrod (Solidago canadesis), the effect of 8-hydroxyquinoline sulphate (8-HQS), silver thiosulphate (STS) and l-methylcyclopropene (l-MCP) were investigated. 8-HQS was used as a continuous treatment at 400 ppm with or without sucrose at 50 g/l. The treatment of STS was used by putting the flower bases at 0.4 mM for 6h with or without sucrose at 50 g/l. l -MCP was used at 0.5 g/m3 for 6h dry or in water. Except the treatment of l -MCP in water, the chemical treatments, which were used, led to the increase vase of life of leaves as well as to the inflorescence of cut solidago spikes compared to the control. The best treatment in this concern was 8-HQS at 400 ppm without sucrose, which resulted in longest vase life of leaves as well as inflorescences and lowest percent loss of fresh weight of initial.
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Eco-friendly methods to control infection of Botrytis cinerea during propagation of grapevines
53-56.Views:268Grey mould (Botrytis cinerea Pers.) is a pathogenic fungus which causes damage to the production of grapevine nursery plant materials especially on the stored canes or on graftings during the callusing period. The conditions, increased temperature and humidity, are ideal for the pathogen during the pre-forcing stage and in the storage Botrytis cinerea can easily infect the outbursting buds as large amounts of grapevine canes are stored in a relatively small place. The fungicide-based management is general in the prevention of gray rot infection but the palette of authorised chemical compounds is narrowed year by year due to the regulations of the European Union. Our aim is to develop an eco-friendly method which combines the use of natural materials with techniques used in organic farming. Effect of the ultraviolet-c light on the Botrytis cinerea was studied. The development characteristics of the pathogen were examined under daylight and dark conditions and experiments were set up with cow’s milk and acetic acid. UV-C light destroyed the developed conidia, however, the radiation stimulates the development of immature propagules. Larger quantities of conidiophores and conidia were formed in daylight compared to culture in the dark, while different conditions did not signifi cantly change the mycelial growth characteristics. The developed bacteria prevented the spread of pathogen mycelia during the test with cow’s milk in Petri dishes, although the smooth development of propagules that occurred did not change the vitality of the fungal colony. Furthermore the growth of Botrytis cinerea fungus mycelia was strongly inhibited by acetic acid.
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Top-dressing of paprika transplants in trays with fertilizers of phosphorus- and nitrogen surplus
47-49.Views:117By our experiments, we wished to answer the question: may top-dressing with nitrogen and phosphorus fertilizers, respectively, improve the quality of transplants grown in trays on a substrate enriched by 2 kg/m3 of retarded fertilizers?
The experiments started in spring and autumn 2002, in a large volume plastic house. The seedlings were grown in trays. Seed was sown directly into KITE trays of 187 cells (28 cm3 volume per cell, 779 seedlings per square meter). The trays were filled by "loose filling" (without packing) with the following soil mixture: 50% Baltic highmoor peat, 50% 'Nitrite lowmoor peat, 1,5 kg/m3 feed chalk, 2 kg/m3 slow acting chemical fertilizer of phosphorus overweight, 2 kg/m3 superphosphate. The test plant was the vegetable paprika variety `Tizenegyes'.
The trials were made in order to clear up if top-dressing done once or twice improves the quality of the seedlings. For this purpose, perfectly soluble fertilizers of phosphorus or nitrogen surplus were used. 3 I fertilizer solution of 0.2% concentration was given per square meter on every single occasion. The control plots received no top-dressing.
The following parameters were registered: stem diameter, plant height, fresh weight of the top, dry matter content of the top, fresh weight of the root system per plant, dry matter content of the roots.
The experimental results with top-dressing have clearly proved the insufficiency of mixing 2 kg/m3 of retarded fertilizer into the substrate, as usual in raising paprika seedlings in trays, because of the long period of transplant raising. According to our experiments the additional nitrogen fertilization influences positively the development of green parts of plants, while the multiple application of fertilizers with higher phosphorus-content helps to develop a strong root system. We suppose, that the more often applied additional fertilizers, maybe the combination of fertilizers with nitrogen and phosphorus amount could give use even better results.
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Possibilities of blossom and twig blight management in organic stone fruit production
103-105.Views:198In this study, possibilities of environmentally-benign plant protection against blossom and twig blight were summarized for organic stone fruit orchards. Symtomps of Monilinia laxa (Aderh. & Ruhl.) Honey) were described and then cultivar susceptibility to blossom and twig blight was discussed. Several sustainable plant protection methods were selected and discussed in details such as mechanical, agrotechnical, biological, and other non-chemical control possibilities (stone powders, plant extracts and restricted chemical materials).
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The relationship of the plant protection and the applied technology in the integrated apple production
11-14.Views:258The indirect elements of the integrated plant protection can infl uence the effectiveness of the chemical control, however their significance are often extenuated. The characteristic of the plants are almost completely disregarded at the protection decisions. The condition can determinate basically the rate of the damages caused by the pests. The plant in good conditional state has higher tolerance and lower susceptibility against the pests. With the optimal general and annual condition we can establish and maintain the harmony between the growth and the bearing, what is the basis of effective plant protection.
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Effects of Foliar Nutrition on Onion Seed Storage under Controlled Atmosphere
101-110.Views:203Storage of fresh fruits and vegetables prolongs their usefulness. The principal goal of storage is to preserve the commodity in its most useable form for the consumer. The extension of storage life and the improvement of quality of fresh fruits and vegetables can be supplied by harvesting at proper maturity, control of post-harvest diseases, chemical treatments, refrigeration, controlled and modified atmospheres. Two successive winter seasons of 2008/2009 and 2009/2010 were conducted under sandy soil conditions to study the effect of spraying with 12 commercial compounds on onion seeds and storage under controlled atmosphere. The germination percentages were 85.50, 86.85, 83.75 and 82.15 for CA1, CA2, CA3 and CA4, respectively. Water content of onion seeds was significantly increased with decreasing storage temperature in all controlled atmospheres. Water content values were 4.48, 4.40, 4.55 and 4.54 for CA1, CA2, CA3 and CA4, respectively. There were significant decreases in water content with increasing exposure periods. The lowest water content was recordednfor the exposure periods of 120 and 240 days. Catalase and peroxidase activities were decreased with the decreasing of storage temperature, whereas malondialdehyde content was increased. The exposure for 120 days recorded the highest catalase activity. The highest value of peroxidase (11.72) was recorded for CA2. Peroxidase activity increased as exposure period increased until 120 days and then decreased. Cold storage temperature (5°C) showed the highest malondialdehyde content followed by room temperature. The CA2 showed the lowest malondialdehyde content compared with other controlled atmospheres. The exposure period of 120 days had the lowest malondialdehyde content.
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Susceptibility of European pear cultivars to Venturia pirina Aderh. infection at a variety collection in Hungary
41-47.Views:253Field sensitivity of 271 European pear genotypes were evaluated in a large variety collection of pear in Hungary during a nine years survey. Substantial differences were detected in the rate of pear scab infection of leaves and fruits. Some 18 per cent of the inspected genotypes remained completely free of infection even in the years with weather favouring to the disease. On the other hand, 78 % of the inspected genotypes were infected in some or more extent. The rate of infection was generally higher on leaves than on fruits. 18.6 % of the genotypes inspected were tolerant to leaf infection and their majority (81.1 %) were tolerant to fruit infection. Some one fi fth of the genotypes (19.7 %) were highly susceptible to leaf infection but only minor rate of them (2.2 %) were highly susceptible to fruit infection. There were 44 genotypes that could be regarded as tolerant to pear scab leaf and fruit infection under fi eld conditions. Some of these genotypes may be suitable to commercial pear growing with highly reduced chemical control against pear but their yield capacity and fruit quality should be evaluated.
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Allelopathic effect of the Cladonia verticillaris lichen extracts and fumarprotocetraric acid on the early growth of germinating seeds and seedlings in Allium cepa L.
31-35.Views:152The allelopathic activity of the different extracts of the lichen Cladonia verticillaris and fumarprotocetraric acid on the early growth of A cepa (IPA 6) seedlings depends on their chemical composition and concentration, respectively. It was observed that the length of the radicle was significantly stimulated by fumarprotocetraric acid at high concentrations and by the total extract of C. verticillaris thalli, which contained a high level of fumarprotocetraric, acid confirmed by HPLC-technique. In addition, it was found, that the phosphate buffer extract, which contained high level of methyl (3-orcinol carboxilate measured by HPLC, reduced the length of the hypocotyls significantly. Under our experimental conditions there was no influence of the different types of extract and fumarprotocetraric acid on the ratio of seed germination, in relation to the control. From the study of HPLC it was found that fumarprotocetraric acid and methyl 13-orcinol carboxilate were present in all extracts at different concentrations, depending on the method of extraction.
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Fire blight in Hungary between 1996 and 2003
67-70.Views:109Shoot blight of pome fruits caused by Erwinia amylovora, i.e. fire blight, is present in numerous countries of Europe. The disease must have entered into Hungary in the middle of the 1990's and it was first noted and, respectively, identified in 1996 (Bacs-Kiskun county). The losses caused by the pathogen appeared — in orchards and scattered sites of production — in four counties, namely Bacs-Kiskun, Baranya, Bekes and Csongrad at the beginning. From June 1996, a process of eliminating infected parts started in the course of a large action performed under the control of the Department of Plant Protection and Agro-Environmental Economy of the Ministry of Agriculture, under the direction of the plant protection inspectors of the then existing Stations of Plant Health and Soil Conservation. The 'operation' against the disease commenced by cutting back out the infected parts of the canopy and, grubbing them out, respectively. As for the spread of the pathogen (1996-1998) it could be observed that the disease entered into Hungary from the south, south-east and then it also spread into the middle part of the country. As a result of adequate official action and efforts as well as of adequate chemical and antibiotic treatments, moreover because of the introduction of more modern technologies of plant cultivation and those of plant protection it can be reported on that the pathogen hardly appears or does not occur at all on the northern, north-western part of the country. The infection also appears mainly on the parts east of the Danube. Cultivars less susceptible or non-susceptible to the disease are planted in recently established orchards what is also a considerable factor in respect of preventing spread of the pathogen.