N.S. El-Mougy, M.M. Abdel-Kader, F. Abdel-Kareem, E.I. Embabi and R. El-Mohamady and H.Abd El-Khair

Transcription

1 Research Journal of Agriculture and Biological Sciences, 7(2): , 2011 ISSN This is a refereed journal and all articles are professionally screened and reviewed 203 ORIGINAL ARTICLES Survey of Fungal Diseases Affecting Some Vegetable Crops and Their Rhizospheric Soilborne Microorganisms Grown under Protected Cultivation System in Egypt N.S. El-Mougy, M.M. Abdel-Kader, F. Abdel-Kareem, E.I. Embabi and R. El-Mohamady and H.Abd El-Khair Plant Pathol. Dept., National Research Centre, Giza, Egypt. ABSTRACT The most reported areas for high production of vegetables under protected cultivation system in ARE were subjected to survey of either root or shoot systems fungal diseases at two growth stages of plant growth. Surveyed vegetable crops, i.e. Cucumber, Pepper, Tomato showing damping-off, root rot and wilt symptoms were subjected to isolation trails for the purpose of isolation the causal organisms. Rhizospheric samples of different healthy and diseased plants were collected at flowering growth stage from the same surveyed plastic houses distributed for determining the frequency occurrence of different fungi and bacteria associated with the root region of healthy and infected roots of cucumber, pepper, tomato and cantaloupe plants. The recorded diseases in surveyed plastic houses were damping-off, root-rot, white rot, wilt, downy & powdery mildews, anthracnose and early & late blights. The root fungal pathogens isolated from rhizospheric soil were Pythium spp., Fusarium spp. Rhizoctonia solani, Macrophomina sp. Sclerotinia spp., Sclerotium rolfsii which recorded in high frequency comparing with other fungal genera Alternaria spp., Aspergillus spp., Penicillium spp. and Trichoderma spp. The genus Fusarium represented in highest records followed by the genus Rhizoctonia and Sclerotium respectively at all assayed samples. Meanwhile, the pathogens referred to genus Pythium, Macrophomina and Sclerotinia were represented in a lesser frequency. Meanwhile the bacterial groups were identified as Bacillus sp., Agrobacerium sp., and non fluorescent Pseudomonas. Key words: Plastic houses, root diseases, foliar diseases, cucumber, pepper, tomato, cantaloupe, soil rhizosphere. Introduction Protected agriculture is considered an important means of increasing the productivity and quality of most vegetable crops. Recently, there has been an increase in interest in protected agriculture (PA) in Egypt. The demand for plastic houses has increased and their use has spread in throughout different regions, where there were protected houses belonging to Governmental agro-research stations and others belonging to public-sector cooperatives. In Egypt, the most common cultivated vegetables under PA system are Cucumber, sweet and hot Pepper, Tomato, Cantaloupe and Eggplant (Anonymous 2008). Under plastic houses conditions such vegetables are reported to be infected with different root and foliar diseases, i.e. damping-off, root rot, white rot, wilt, downy and powdery mildew (Daughtrey & Horst 1990; Simone & Momol 2001 and Hochmuth 2003). The impact of plant pests on the aspiring producer of greenhouse vegetables is direct and significant. The prospective producer must understand that the greenhouse condition is a paradise for both the crop and the accompanying pests that afflict it. Plastic houses have led to changes in the microclimate of protected crops. Restricted air exchange results in the atmospheric humidity being much higher inside insulated greenhouses than conventional ones which encourage several plant diseases and cause physiological disorders. Climate change could alter stages and rates of development of the pathogen, modify host resistance, and result in changes in the physiology of hostpathogen interactions (Coakley et al. 1999). The aim of the present work was designed to monitor the diseases infection and associated rhizospheric microorganisms of some vegetables grown under protected cultivation system at different Governmental agro-research stations plastic houses located at different locations throughout Egypt. Corresponding Author: N.S. El-Mougy, Plant Pathol. Dept., National Research Centre, Giza, Egypt. nehal_nrc@yahoo.com

2 204 Material and Methods Surveying of Vegetable Fungal Diseases Throughout Different Protected Cultivation Locations: The most reported areas for high production of vegetables under protected cultivation system in ARE were subjected to survey of either root or shoot systems diseases at two growth stages of plant growth, i.e. seedling (30-60 days after transplanting) and maturity ( days after transplanting). The percentage of different diseases incidence was recorded at different commercial greenhouses distributed in five governorates, i.e. Giza, Cairo, Kalubia, Ismaelia and Behiera. The average percentages of root and foliar diseases infections were calculated as the number of infected plants in relative to the total number of examined plants. Crop monitoring is the continually on-going surveillance to detect the presence of a pest or disease at the very early stages of development of the disease or pest population, before economic damage has occurred. Therefore, the research team involved in working the crop monitoring are enough qualified of the common disease problems and what to look for to detect the presence of disease symptoms in certain crop. Collecting Different Soil and Rhizospheric Samples: Soil microorganisms, fungi and bacteria, associated with the root region of healthy and infected roots of Cucumber, Pepper and Tomato plants were isolated following the method developed by Louw and Weblely (1959) for studying the microflora of the root region. The plate count technique according to Allen (1961) was followed for both total fungal and bacterial counts. Rhizospheric samples of different healthy and diseased plants were collected at flowering growth stage from the same surveyed plastic houses distributed in five governorates as previously mentioned. The frequency occurrence of different fungi in assayed rhizospheric soil samples were recorded. The total bacterial count and common bacterial groups was also determined using dilution method. Identification of common bacterial groups was made according to cultural and morphological characters (Schaad, 1988), on selective media and ability of maceration of potato slices. Vegetable crops, i.e. Cucumber, Pepper, Tomato showing damping-off, root rot and wilt symptoms were subjected to isolation trails for the purpose of isolation the causal organisms. The isolated fungi were firstly purified using single spore or hyphal tip techniques (Mundkur 1959) then identified according to the cultural morphological growth and microscopical characters as described by Gilman (1957), Barnett and Hunter (1972) and Nelson et al. (1983). Results and discussion Surveying of Vegetable Diseases Throughout Different Protected Cultivation Locations: Results of surveyed different vegetable crops, i.e. Cucumber, Pepper, Tomato and Cantaloupe grown under PA in different governorates in Egypt for diseases incidence are shown in Tables (1,2,3,4,5). The recorded diseases were damping-off, root-rot, white rot, wilt, downy & powdery mildews, anthracnose and early & late blights. The obtained results revealed that the surveyed plants at early stages (30-60 days after transplanting) showed root infections expressed at highest records with wilt infection followed by root-rot and damping-off. The foliar infection as powdery and downy mildews was detected in lesser records and going up with the increasing of plant age to reach their maximum at days. Meanwhile, damping-off and root-rot infections were not observed at the late growth stage of surveyed plants. Cantaloupe infection with damping-off, root rot and wilt diseases was only recorded at plastic houses located at Al-Kasasen region of Ismaelia governorate. Tomato early and late blights were recorded at both stages of plant growth wherever surveyed plastic houses located at Giza and Cairo governorates. It is observed that the recorded data indicate that all cultivars of various surveyed vegetable crops grown under protected cultivation system are susceptible to disease infection with both soilborne and airborne plant pathogens at all surveyed locations. In this regard, it was recorded that the most important root diseases in greenhouses systems are caused by fungi of various species of Pythium and Phytophthora. These fungi are known collectively as water moulds and are important pathogens in soils in field (Simone and Momol 2001). Moreover, disease organisms, insects, and nematodes can cause serious problems in plastic houses. Without a real winter period, populations of pests continue to build, and many are sustained throughout the year. With this mild climate comes the adaptability of both temperate and tropical pests, thus presenting a large number of potential problems for greenhouse crops (Daughtrey and Horst 1990). These reports are in a harmony with the present results of our study. Surveyed production areas were examined for the initial symptoms of disease during routine crop maintenance activities, whereas, the earlier a disease is found and identified.

3 205 The most recorded common diseases affecting greenhouse vegetables were also previously reported in Florida (Simone and Momol 2001; Hochmuth, et al., 2001; Jovicich et al., 2004; Rich et al., 2005; Hochmuth 2005). It is very interesting to note that during survey processes, a sever Sclerotinia foliage blight disease symptoms were observed on sweet and hot pepper plants grown in the Protected Cultivation Station, Ministry of Agriculture located at Tookh, Kalubia governorate. The percentage of disease incidence recorded as 3.4% for sweet pepper (Khyrratte cv.) and 3.2% for hot pepper (Kaha cv.). The causal fungus was isolated and identified as Sclerotinia minor Jagger. According to the available literature, this is thought to be the first report of Sclerotinia minor Jagger causing Sclerotinia foliage blight disease of pepper in Egypt (El-Mougy et al., 2011). Also, at the same location, a sever Sclerotinia blight disease symptoms was observed on cucumber plants grown under the same conditions. The percentage of disease incidence recorded as 2.4, 2.8 and 3.1% for Hisham, D.P. 162 and Hykal cultivar varieties. The causal fungus was isolated and identified as Sclerotinia sclerotiorum (Lib.) de Bary. According to the available literature, this is thought to be the first report of Sclerotinia sclerotiorum (Lib.) de Bary causing Sclerotinia blight disease of Cucumber in Egypt (Imbabi et al., 2011). Isolation Different Soilborne Microorganisms, Associated with Healthy and Infected Vegetable Plants: Soil microorganisms, fungi and bacteria, associated with the root region of healthy and infected roots of Cucumber, Pepper and Tomato plants were isolated following the method developed by Louw and Weblely (1959) for studying the microflora of the root region. The plate count technique according to Allen (1961) was followed for both total fungal and bacterial counts. Rhizospheric samples of different healthy and diseased plants were collected at flowering growth stage from the same surveyed plastic houses distributed in five governorates as previously mentioned. The frequency occurrence of different fungi in assayed rhizospheric soil samples were recorded. The total bacterial count and common bacterial groups was also determined using dilution method. Identification of common bacterial groups was made according to cultural and morphological characters (Schaad, 1988), on selective media and ability of maceration of potato slices. The obtained results (Table 6 and Figure 1) showed the frequency occurrence of different fungi in assayed rhizospheric soil samples. The root fungal pathogens e.g. Pythium spp., Fusarium spp. Rhizoctonia solani, Macrophomina sp. Sclerotinia spp., Sclerothium rolfsii were recorded in high frequency comparing with other fungal genera Alternaria spp., Aspergillus spp., Penicillium spp. and Trichoderma spp. The genus Fusarium represented in highest records followed by the genus Rhizoctonia and Sclerotium respectively at all assayed samples. Meanwhile, the pathogens referred to genus Pythium, Macrophomina and Sclerotinia were represented in a lesser frequency. The obtained data interestingly indicate that the frequency occurrence of the root pathogens confirm the previously recorded data (Tables 1 to 5) concerning the percentages of root infection with damping-off, root rot and wilt diseases and could be considered as parallel decline shape. Vegetable crops, i.e. Cucumber, Pepper, Tomato showing damping-off, root rot and wilt symptoms were subjected to isolation trails for the purpose of isolation the causal organisms. The isolated fungi were firstly purified using single spore or hyphal tip techniques then identified according to the cultural morphological growth and microscopical characters as described by Gilman (1957), Barnett and Hunter (1972) and Nelson et al. (1983). The isolated fungi were identified as Pythium sp., Fusarium solani, F. oxysporum, Rhizoctonia solani, Macrophomina phaseolina, Sclerotinia sclerotiorum, Sclerotinia minor, Sclerotium rolfsii, Alternaria solani as well as Trichoderma harzianum, T. viride and T. hamatum. The isolated fungi were previously recorded as the main causal of root diseases of surveyed vegetables (Langston, D.B. Jr. 1999; Matheron and Porchas 2000; Jones 2001; Jude and Richard 2001; Elizabeth et al., 2001; Pernezny et al., 2003; Momol and Pernezny 2005). Concerning the total bacterial counts, results in Table (7) showed that the rhizosphere samples of cucumber, pepper, tomato and cantaloupe were differed in their total bacterial counts. Results also revealed that the four main bacterial groups were common in most plants rhizosphere. The groups were named as group (A), group (B), group (C) and group (D) according to cultural characters. In rhizospheric samples collected from Dokki plastichouses showed a high records of bacterial count in cucumber rhizosphere, compared to the bacterial count in pepper and tomato samples, respectively. The bacterial group (A) was common dominant in all rhizospheric samples followed by group (B) and (D), respectively. Meanwhile the group (C) represented at least records. Results showed that the groups (A & B) were isolated from all rhizospheric samples collected from the all governorates. The isolated bacteria are shown in Table (8). They revealed that the cultural and morphological characters, specific characters on selective media and ability of potato slices macerations of four main bacterial groups. The colonies of group (A) were circular, convex, entire, smooth, opaque, butyrous and creamy white and their cells were Gram positive and rods. The colonies of group (B) were circular, raised, entire, smooth, translucent, butyrous and white and their cells were Gram negative and short rods.

4 206 Fig. 1: Frequency occurrence of isolated fungi from the rhizosphere of different vegetable crops grown under protected cultivation system at various regions, located at five governorates.

5 207 Table 1: (A and B) Survey of soilborne and foliar diseases of different vegetable crops grown under protected cultivation system at Dokki and Haram locations at Giza governorate. A- During the period of days from transplanting (January-February) Dokki Cucumber Safa Kasabtan Sweet pepper Khyrratte Godiun Hot pepper Sina Tomato Agyaad Lora Al-Haram Cucumber Safa Kasabtan Sweet pepper Khyrratte Godiun Hot pepper Sina Tomato Agyaad Lora Table 2: (A and B) Survey of soilborne and foliar diseases of different vegetable crops grown under protected cultivation system at Gazirat Al-Dahab location at Cairo governorate. A- During the period of days from transplanting (January-February) 2011 plant variety surveyed Gazirat Cucumber Hisham Al-Dahab Safa Kasabtan Sweet pepper Khyrratte Godiun Hot pepper Sina Tomato Agyaad Lora plant variety surveyed Gazirat Cucumber Hisham Al-Dahab Safa Kasabtan Sweet pepper Khyrratte Godiun Hot pepper Sina Tomato Agyaad Lora Table 3: (A and B) Survey of soilborne and foliar diseases of different vegetable crops grown under protected cultivation system at Tookh location at Kalubia governorate. A- During the period of days from transplanting (January-February) plant variety surveyed Tookh Cucumber Hisham D.P Hykal Sweet pepper Khyrratte Hot pepper Kaha Tomato

6 208 plant variety surveyed plastic house Damping Root Sclerot wilt Powdery Downy Early Late off rot iniablight mildew mildew blight blight Tookh Cucumber Hisham D.P Hykal Sweet pepper Khyrratte Hot pepper Kaha Tomato Not cultivated Table 4: (A and B) Survey of soilborne and foliar diseases of different vegetable crops grown under protected cultivation system at different locations at Ismaelia governorate A- During the period of days from transplanting (January-February) Al-Tal- Cucmber Hisham Alkabeer Pepper Spanish Tomato Abu-Soaer Cucmber Hisham Pepper Spanish Tomato Al-Kassasen Cucmber Hisham Pepper Spanish Tomato Cantaloupe Al-Tal- Cucmber Hisham Alkabeer Pepper Spanish Tomato Abu-Soaer Cucmber Hisham Pepper Spanish Tomato Al-Kassasen Cucmber Hisham Pepper Spanish Tomato Cantaloupe Not cultivated. Table 5: (A and B) Survey of soilborne and foliar diseases of different vegetable crops grown under protected cultivation system at Nubaria location at Biehera governorate. A- During the period of days from transplanting (January-February) Nubaria Cucumber Hisham Hykal Sweet pepper Khyrratte Hot pepper Kaha Tomato Nubaria Cucumber Hisham Hykal Sweet pepper Khyrratte Hot pepper Kaha Tomato Not cultivated.

7 209 Table 6: Occurrence of isolated fungi from the rhizosphere of different vegetable crops grown under protected cultivation system at different locations in five governorates. Frequecy occurrence of rhizospheric fungi % Governorate Location Host Phythium Fusarium R. Solani Macrophomin Seclerotinia S. rolfsii Alternaria Aspergillus Penicillium Trichderma Others plant spp. spp. spp. spp. spp. spp. spp. spp. Giza Dokki Cucmber Pepper Tomato Al-Haram Cucmber Pepper Tomato Cairo Gazirat Cucmber Al-Dahab Pepper Tomato Kalubia Tookh Cucmber Pepper Ismaelia Al-Tal- Cucmber Alkabeer Pepper Abu-Soaer Cucmber Pepper Al-Kassasen Cucmber Pepper Cantaloupe Biehera Nubaria Cucmber Pepper Table 7: Occurrence of isolated bacteria from the rhizosphere of different vegetable crops grown under protected cultivation system at different locations in five governorates. Governorate Location Host plant Total bacterial Frequency % of common bacterial groups Count (cfu/g) Group A Group B Group C Group D Others (Bacillus sp.) (Agrobacterium Non- (Bacillus sp.) sp.) fluorescent pseudomona Giza Dokki Cucmber Pepper Tomato Al-Haram Cucmber Pepper Tomato Cairo Gazirat Cucmber 1.3x Al-Dahab Pepper Tomato Kalubia Tookh Cucmber Pepper Ismaelia Al-TalAlkabeer Cucmber 4.5x Pepper Abu-Soaer Cucmber 1.7x Pepper Al-Kasasen Cucmber Pepper Cantaloupe Biehera Nubaria Cucmber Pepper Table 8: Cultural specific and morphological characters of common bacteria groups isolated from rhizosphere of different vegetable crops grown under protected cultivation system. Characteristics of bacterial groups Group A Group B Group C Group D (Bacillus sp.) (Agrobacterium sp.) (Non-fluorescent Pseudomonas) (Bacillus sp.) 1-Cultural characters on nutrient Circular Irregular Rhizoid glucose 2% agar medium Circular Convex Raised Raised Flat Entire Smooth Entire Smooth Lobate Smooth Lobate Smooth Opaque Translucent Translucent Translucent Butyrous Butyrous Butyrous Butyrous creamy white White White White 2- Morphological characters Gram positive Rods Gram negative Gram negative Short rods Gram positive Short rods Short rods Rods 3- Specific characters on selective media* - Colonies YDC medium. White White White White - Colonies on M&S medium. Orange White White White - Fluorescent pigment on KB Negative Negative Negative Negative medium - Growth on D-1 medium No growth Growth No growth No growth 4-Mecearation of potato slices Negative Negative Negative Negative *YDC =Yeast extract-dextrose Caco 3 medium, M&S = Miller and Schroth medium, and KB = King s medium agar.

8 210 The colonies of group (C) were irregular, raised, lobate, smooth, translucent, butyrous and white and their cells were Gram negative and short rods. The colonies of group (D) were rhizoid, flat, lobate, smooth, translucent, butyrous and white and their cells were Gram positive. According to the above specific characteristics, the four bacterial groups were identified as follows ;group (A) as Bacillus sp., group (B) as Agrobacerium sp., group (C) as non fluorescent Pseudomonas and group (D) as Bacillus sp. In this regards, plant pathogenic bacteria are dominant soilborne microorganisms which cause many serious diseases of plants throughout the world (Vidhyasekaran 2002) causing relatively damage and economic cost (Kennedy and Alcorn 1980). Vidaver and Lambrecht (2004) reported that s`urvival of plant pathogenic bacteria in nature occurs most commonly in plant debris left on the soil surface, in and on seeds, in soil, and in association with perennial hosts. Knowledge of survival is usually essential to intervene in dissemination and for disease management. They added that Dissemination commonly occurs by windblown soil and sand particles that cause plant wounding, particularly during or after rains or storms. Conclusion: Because plant population densities in greenhouses are usually very high and closely confined by the greenhouse walls, some virus diseases, foliar blights, leaf spots, stem and fruit rots, root rots and other diseases can become severe very quickly. Use strict sanitation procedures for germinating seed and growing transplants. Prior to setting transplants, the growing medium (soil, soil-less mix, or hydroponic solution) should be checked for nutrients, then monitored weekly for hydroponic culture or every two weeks for soil and soil-less mix culture until the crop has been harvested. Diagnose all problems promptly. These include diseases, insect, nutritional, and growth problems. Promptly remove all diseased leaves, fruits, or entire plants to avoid spread of disease. These procedures are recommended for all greenhouse vegetable and herb growers to minimize the risk of introducing plant pathogens, reduce disease severity if pathogens are present, and to lessen dependency on labeled fungicides and nematicides. Pesticides, including biological control agents that may be commercially available in the future, must be used. Acknowledgement This work was supported financially by the Science and Technology Development Fund (STDF), Egypt, Grant No References Allen, O.N., Experiments on Soil Bacteriology. Burgess Publishing Co., Minnesota, USA, pp: 214 Anonymous, Yearbook of statistics of Ministry of Agriculture. (Agricultural Economical and Statistical Department, Arab Republic of Egypt: Cairo., pp: 137 [In Arabic]. Barnett, H.L. and B.B. Hunter, Illustrated genera of imperfect fungi. Burgess Publishing Company. Minneapolis, Minnesota, pp: 241. Coakley, S.M., H. Scherm and S. Chakraborty, Climate change and plant diseases management. Annual Review of Phytopathology. 37: DOI: /annurev.phyto Daughtrey, M.L. and P.K. Horst, Biology and management of diseases of greenhouse florist crops. In 1991 Recommendations for the integrated management of greenhouse florist crops. Part II. Management of pests and crop growth. New York State College of Agr. And Life Sci., Cornell Univ., Ithaca, NY Elizabeth M., Lamb, N. Erin, F. Rosskop and M. Ronald Sonoda, Fusarium Stem Rot of Greenhouse Peppers. In "Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. at ` El-Mougy, N.S., M.D.I.H. Aly, E.I. Imbabi and M.M. Abdel-Kader, First Record of Sclerotinia Foliage Blight Disease on Pepper under Protected Cultivation System in Egypt. Proc. 12 th Egyptian Phytopathological Society, 3-4. ARC, Cairo, Egypt. Gilman, J.C., A manual of soil fungi. Iowa State University Press, Ames, Iowa, U.S.A. pp: 450. Hochmuth, G., Vegetable Crops. "Vegetable crops service programs", Institute of Food and Agricultural Sciences, University of Florida. at Hochmuth, R.C., Greenhouse Cucumber Production. In the Florida Greenhouse Vegetable Production Handbook. Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. at `

9 211 Hochmuth, G.J., W.D. Homas, M.S. Sweat and R.C. Hochmuth, Financial Considerations - Florida Greenhouse Vegetable Production Handbook, In the Florida Greenhouse Vegetable Production Handbook. Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. at ` Imbabi, E.I., N.S. El-Mougy, M.M. Abdel-Kader and S.M. Lashin, First Record of Sclerotinia Blight Disease on Cucumber under Protected Cultivation System in Egypt. Proc. 12 th Egyptian Phytopathological Society, 3-4. ARC, Cairo, Egypt. Jones, P.H., Preconstruction Considerations - Florida Greenhouse Vegetable Production Handbook, the Florida Greenhouse Vegetable Production Handbook. Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. at ` Jovicich, E., D.J. Cantliffe, S.A. Sargent and L.S. Osborne, Production of Greenhouse-Grown Peppers in Florida. The Department of Horticultural Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. at ` Jude, B.T. and A.A. Richard, Northeast Pepper Integrated Pest Management (IPM) Manual. University of Connecticut, Cooperative Extension System., pp: 136. Kennedy, B.W. and S.M. Alcorn, Estimates of U.S. crop losses to prokaryote plant pathogens. Plant Dis., 64: Langston, D.B. Jr., Squash and cucumber diseases. Pages in: Commercial Production and Management of Squash and Cucumbers. W.T. Kelly, ed. University of Georgia Cooperative Extension Service Bulletin, 1178 Louw, H.A., D.W. Weblely, The bacteriology of root region of cat plant grown under controlled pot culture conditions. J. Appl. Bacteriol., 22: Matheron, M.E. and M. Porchas, Comparison of Five Fungicides on Development of Root, Crown, and Fruit Rot of Chile Pepper and Recovery of Phytophthora capsici from Soil. Plant Dis., 84: Momol, T. and K. Pernezny, Florida Plant Disease Management Guide: Tomato. Plant Disease Management Guide, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. at Mundkur, B.B., (Ed.), Fungi and plant diseases. Macmillan and Co. Ltd, London. pp: 246. Nelson, P.E., T.A. Toussoun and W.F.O Marasan, Fusarium spp. An illustrated manual for identification. The Pennsylvania Univ. Press, press, park., pp: 218. Pernezny, K., P.D. Roberts, J.F. Murphy and N.P. Goldberg, Compendium of Pepper Diseases. APS Press, St. Paul, MN., pp: 63. Rich, J.R., M.T. Momol, S.E. Webb and F.A. Johnson, Considerations for Managing Greenhouse Pests - Florida Greenhouse Vegetable Production Handbook. Plant Disease Management Guide, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. at Schaad, N.W., Laboratory Guide for Identification of Plant Pathogenic Bacteria., pp: Ammeric. Phytopathol. Soc., St. Paul, Minnesota. Simone, G.W. and M.T. Momol, Vegetable Disease Recognition and Management. Florida Greenhouse Vegetable Production Handbook at: Vidaver, A.K. and P.A. Lambrecht, Bacteria as plant pathogens. The Plant Health Instructor. DOI: / P H I - I a t : Vidhyasekaran, P., Bacterial disease resistance in plants. Molecular biology and biotechnological applications. pp: 452. The Haworth Press, N.Y. Binghamton.