Plant Pathology
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Plant Terminology
PLANT TERMINOLOGY Plant terminology for the identification of plants is a necessary evil in order to be more exact, to cut down on lengthy descriptions, and of course to use the more professional texts. I have tried to keep the terminology in the database fairly simple but there is no choice in using many descriptive terms. The following slides deal with the most commonly used terms (more specialized terms are given in family descriptions where needed). Professional texts vary from fairly friendly to down-right difficult in their use of terminology. Do not be dismayed if a plant or plant part does not seem to fit any given term, or that some terms seem to be vague or have more than one definition – that’s life. In addition this subject has deep historical roots and plant terminology has evolved with the science although some authors have not. There are many texts that define and illustrate plant terminology – I use Plant Identification Terminology, An illustrated Glossary by Harris and Harris (see CREDITS) and others. Most plant books have at least some terms defined. To really begin to appreciate the diversity of plants, a good text on plant systematics or Classification is a necessity. PLANT TERMS - Typical Plant - Introduction [V. Max Brown] Plant Shoot System of Plant – stem, leaves and flowers. This is the photosynthetic part of the plant using CO2 (from the air) and light to produce food which is used by the plant and stored in the Root System. The shoot system is also the reproductive part of the plant forming flowers (highly modified leaves); however some plants also have forms of asexual reproduction The stem is composed of Nodes (points of origin for leaves and branches) and Internodes Root System of Plant – supports the plant, stores food and uptakes water and minerals used in the shoot System PLANT TERMS - Typical Perfect Flower [V. -
1 Principles of Plant Pathology Path
PRINCIPLES OF PLANT PATHOLOGY PATH 271 (1+1) Prepared By DR. P. KISHORE VARMA, ASSISTANT PROFESSOR, DEPARTMENT OF PLANT PATHOLOGY AGRICULTURAL COLLEGE, ASWARAOPET 507 301 1 LECTURE 1 INTRODUCTION TO PLANT PATHOLOGY Why Plant Pathology? Plants are essential for maintenance of life. Plants not only sustain the man and animals, they are also the source of food for multitudes of micro-organisms living in the ecosystem. Thus, while man has been able to subjugate plants and animals for his own use, the competing micro-organisms still defy his efforts and claim a major share of resources which man would like to use for himself. It is in this context that the need for fighting the competing micro-organisms and other agencies that lack loss of productivity has been felt. The attack on plants by these micro-organisms changed the appearance and productivity of the crop and this observed change was called a disease. Plant diseases have been considered as stubborn barriers to the rapid progress of food production. We call a plant healthy only so long as it continues to perform all its normal physiological activities and give the expected yield according to its genetic potentiality. Physiological activities of a healthy plant 1. Normal cell division, differentiation and development. 2. Uptake of water and nutrients from the soil. 3. Synthesis of food from sunlight by photosynthesis. 4. Translocation of water and food to the sites of necessity through xylem and phloem. 5. Metabolism of synthesized material 6. Reproduction A diseased plant fails to perform one or more of these functions. -
Cherry Leaf Spot
CHERRY LEAF SPOT 695 maturely defoliated produced fewer blossoms the following year, the flowers were poorly developed and slower in opening, fewer cherries ripened, and the cherries were smaller. Many fruit spurs died, and the crop was greatly reduced on the spurs that survived. By reducing shoot growth and spur Cherry development, the defoliation lowered the yield for several years. Following the worst outbreak of Leaf Spot cherry leaf spot on record in the Cum- berland-Shenandoah Valley in 1945, thousands of sour cherry trees died and F. H. Lewis many others had severe injuries. In Virginia on trees defoliated in Cherry leaf spot, caused by the para- May and June of 1945, the average sitic fungus Coccomyces hiemalis^ is one of weight of the buds in late summer was the major factors that determine the 90 milligrams.' The buds on trees that cost of producing cherries and the had retained their foliage averaged 147 yield and quality of the fruit. milligrams in weight. The smaller buds The disease occurs on the sour did not have enough vitality to survive cherry, Prunus cerasus, sweet cherry, P, the winter. All unsprayed trees died. avium, and the mahaleb cherry, P, None of the trees died in one orchard mahaleb, wherever they are grown where sprays had delayed defoliation under conditions that favor the sur- 4 weeks or more. vival of the fungus. That includes our Heavy early defoliation in West Vir- eastern and central producing areas ginia in 1945 stimulated the produc- and the more humid areas in the West. tion of secondary growth on 64 percent Because it has been most serious on of the terminals about 2 weeks after sour cherry in the Eastern and Central harvest. -
Plant-Parasitic Algae (Chlorophyta: Trentepohliales) in American Samoa1
Plant-Parasitic Algae (Chlorophyta: Trentepohliales) in American Samoa1 Fnd E. Erooks 2 Abstract: A survey conducted betweenJune 2000 and May 2002 on the island of Tutuila, American Samoa, recorded filamentous green algae of the order Tren tepohliales (CWorophyta) and their plant hosts. Putative pathogenicity of the parasitic genus Cephaleuros and its lichenized state, Strig;ula, was also inves tigated. Three genera and nine species were identified: Cephaleuros (five spp.), Phycopeltis (two spp.), and Stomatochroon (two spp.). A widely distributed species of Trentepohlia was not classified. These algae occurred on 146 plant species and cultivars in 101 genera and 48 families; 90% of the hosts were dicotyledonous plants. Cephaleuros spp. have aroused worldwide curiosity, confusion, and con cern for over a century. Their hyphaelike filaments, sporangiophores, and as sociated plant damage have led unsuspecting plant pathologists to misidentify them as fungi, and some phycologists question their parasitic ability. Of the five species of Cephaleuros identified, C. virescens was the most prevalent, followed by C. parasiticus. Leaf tissue beneath thalli of Cephaleuros spp. on 124 different hosts was dissected with a scalpel and depth of necrosis evaluated using a four point scale. No injury was observed beneath thalli on 6% of the hosts, but full thickness necrosis occurred on leaves of 43% of hosts. Tissue damage beneath nonlichenized Cephaleuros thalli was equal to or greater than damage beneath lichenized thalli (Strig;ula elegans). In spite of moderate to severe leaf necrosis caused by Cephaleuros spp., damage was usually confined to older leaves near the base of plants. Unhealthy, crowded, poorly maintained plants tended to have the highest percentage of leaf surface area affected by TrentepoWiales. -
Effect of Foliar Fungicides on Relative Chlorophyll Content, Green Leaf Area, Yield and Test Weight of Winter Wheat
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by SHAREOK repository EFFECT OF FOLIAR FUNGICIDES ON RELATIVE CHLOROPHYLL CONTENT, GREEN LEAF AREA, YIELD AND TEST WEIGHT OF WINTER WHEAT By NATHALIA GRAF-GRACHET Bachelor of Science in Agricultural Engineering Universidade Federal de São Carlos Araras, São Paulo, Brazil 2012 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE May, 2015 EFFECT OF FOLIAR FUNGICIDES ON RELATIVE CHLOROPHYLL CONTENT, GREEN LEAF AREA, YIELD AND TEST WEIGHT OF WINTER WHEAT Thesis Approved: Dr. Robert M. Hunger Thesis Adviser Dr. John Damicone Dr. Jeffrey Edwards Dr. Mark Payton ii ACKNOWLEDGEMENTS I express my immense gratitude to my adviser, Dr. Robert Hunger. I am not able to describe the impact his guidance has had in my life. It is certainly beyond everything I ever deserved. I am very fortunate for having such an extraordinary mentor. For her guidance, I express my sincere gratitude to Dr. Carla Garzon, who kindly offered me incredible opportunities at OSU. A special thank you to all faculty and staff members of the Department of Entomology and Plant Pathology. I extend this special thank you to all the friends I have made here in the US, and to my dearest friends in Brazil. I am extremely lucky for having such amazing people in my life. Finally, I express my simple gratitude to my parents and sister, Mario, Roseli and Marina, who are the most important people in my life. -
Studies on Seed Germination, Seedling Growth, and in Vitro Shoot
HORTSCIENCE 44(3):751–756. 2009. plantlets are detached from the mother plant that are dried and planted. However, seed propagation is more feasible and recommen- Studies on Seed Germination, Seedling ded for survival of rare species (Van Wyk and Smith, 1996). If this species has to be Growth, and In Vitro Shoot Induction propagated on a large scale by means of seed or tissue culture methods, then currently there of Aloe ferox Mill., a Commercially is no basic information available on these aspects. Aloes are succulent and warm-cli- mate plants, where both temperature and Important Species water play an important role in establishing Michael W. Bairu, Manoj G. Kulkarni, Rene´e A. Street, Rofhiwa them. This study was therefore conducted to B. Mulaudzi, and Johannes Van Staden1 examine 1) the effects of different temper- atures, growth-promoting substances, and Research Centre for Plant Growth and Development, School of Biological watering frequencies on seed germination and Conservation Sciences, University of KwaZulu-Natal Pietermaritzburg, and seedling growth of A. ferox; and 2) to Private Bag X01, Scottsville 3209, South Africa assess the applicability of an in vitro propa- gation protocol developed for other Aloe spp. Additional index words. cytokinins, growth regulators, multiplication rate, smoke solutions, temperature, tissue culture Materials and Methods Abstract. A study was done to investigate the effects of some physical and chemical factors on growth and development of Aloe ferox ex vitro and in vitro. The effects of light, Seed collection. Dried seeds of A. ferox temperature, and smoke–water on seed germination, ex vitro seedling growth require- were collected between the middle to the end ments, and effect of germination medium and cytokinins on shoot induction and of August from the Botanical Garden, Uni- multiplication in vitro were investigated. -
Chapter 5: the Shoot System I: the Stem
Chapter 5 The Shoot System I: The Stem THE FUNCTIONS AND ORGANIZATION OF THE SHOOT SYSTEM PRIMARY GROWTH AND STEM ANATOMY Primary Tissues of Dicot Stems Develop from the Primary Meristems The Distribution of the Primary Vascular Bundles Depends on the Position of Leaves Primary Growth Differs in Monocot and Dicot Stems SECONDARY GROWTH AND THE ANATOMY OF WOOD Secondary Xylem and Phloem Develop from Vascular Cambium Wood Is Composed of Secondary Xylem Gymnosperm Wood Differs from Angiosperm Wood Bark Is Composed of Secondary Phloem and Periderm Buds Are Compressed Branches Waiting to Elongate Some Monocot Stems Have Secondary Growth STEM MODIFICATIONS FOR SPECIAL FUNCTIONS THE ECONOMIC VALUE OF WOODY STEMS SUMMARY ECONOMIC BOTANY: How Do You Make A Barrel? 1 KEY CONCEPTS 1. The shoot system is composed of the stem and its lateral appendages: leaves, buds, and flowers. Leaves are arranged in different patterns (phyllotaxis): alternate, opposite, whorled, and spiral. 2. Stems provide support to the leaves, buds, and flowers. They conduct water and nutrients and produce new cells in meristems (shoot apical meristem, primary and secondary meristems). 3. Dicot stems and monocot stems are usually different. Dicot stems tend to have vascular bundles distributed in a ring, whereas in monocot stems they tend to be scattered. 4. Stems are composed of the following: epidermis, cortex and pith, xylem and phloem, and periderm. 5. Secondary xylem is formed by the division of cells in the vascular cambium and is called wood. The bark is composed of all of the tissues outside the vascular cambium, including the periderm (formed from cork cambium) and the secondary phloem. -
Cephaleuros Species, the Plant-Parasitic Green Algae
Plant Disease Aug. 2008 PD-43 Cephaleuros Species, the Plant-Parasitic Green Algae Scot C. Nelson Department of Plant and Environmental Protection Sciences ephaleuros species are filamentous green algae For information on other Cephaleuros species and and parasites of higher plants. In Hawai‘i, at least their diseases in our region, please refer to the technical twoC of horticultural importance are known: Cephaleu- report by Fred Brooks (in References). To see images of ros virescens and Cephaleuros parasiticus. Typically Cephaleuros minimus on noni in American Samoa, visit harmless, generally causing minor diseases character- the Hawai‘i Pest and Disease Image Gallery (www.ctahr. ized by negligible leaf spots, on certain crops in moist hawaii.edu/nelsons/Misc), and click on “noni.” environments these algal diseases can cause economic injury to plant leaves, fruits, and stems. C. virescens is The pathogen the most frequently reported algal pathogen of higher The disease is called algal leaf spot, algal fruit spot, and plants worldwide and has the broadest host range among green scurf; Cephaleuros infections on tea and coffee Cephaleuros species. Frequent rains and warm weather plants have been called “red rust.” These are aerophilic, are favorable conditions for these pathogens. For hosts, filamentous green algae. Although aerophilic and ter- poor plant nutrition, poor soil drainage, and stagnant air restrial, they require a film of water to complete their are predisposing factors to infection by the algae. life cycles. The genus Cephaleuros is a member of the Symptoms and crop damage can vary greatly depend- Trentepohliales and a unique order, Chlorophyta, which ing on the combination of Cephaleuros species, hosts and contains the photosynthetic organisms known as green environments. -
Principal Types of Vegetative Shoot Apex Organization in Vascular Plants1
PRINCIPAL TYPES OF VEGETATIVE SHOOT APEX ORGANIZATION IN VASCULAR PLANTS1 RICHARD A. POPHAM Department of Botany and Plant Pathology, The Ohio State University, Columbus 10 Before progress can be made in research, a problem must be recognized. Once the problem has been perceived, a research program may be directed toward a solution. The problem of how and where a shoot grows and the organization of the shoot apex was apparently first conceived by Kaspar Friedrich Wolff (1759). Although his observations on the structure, formation, and growth of cells were fantastically inaccurate, he made a great contribution to our knowledge of the growing plant by setting forth a new and important problem. In a very real sense, Wolff is the father of developmental plant anatomy. Disagreement is the life blood of many research problems. Strenuous opposition is often engendered by a dogmatic statement or a theory which is proposed as a universal truth. Opposition to Wolff's (1759) original proposition regarding the organization and growth of shoot apices prompted plant anatomists, some 85 years later, to investigate the truth of the statement. The factual solution of the problem of shoot apex organization had its beginnings in the work of Nageli (1845). Following this work on many lower cryptogams, Nageli concluded that the cells of all tissues of the shoot of cryptogams and higher plants have their genesis in a single apical cell. The new-born apical cell theory supported by Hofmeister (1851) and others provided the impetus for a renewed, vigorous attack on the problem of shoot apex organization. A little later a new proposal, Hanstein's (1868) histogen theory was born of more careful observations and in a mind unfettered by the prevailing fanaticism of the apical cell theorists. -
Etiology,Loss, Symptoms and Control of Diseases
Phytopathology is a branch of Botany that deals with causal organism,etiology,loss, symptoms and control of diseases. ETIOLOGY:-Science of cause of disease. Pathology (Greek word‘Pathos’ and ‘Logos’.) Pathos =Suffering Logos=Study “Study of Plant Sufferings” Or “Study of Plant Diseases”. FATHER OF PLANT PATHOLOGY- ANTON de Bary. Aims of plant pathology } To make a survey of the living as well as non- living causes of the diseases. } To study the different types of mechanisms by which the diseases are developed in plants. } To elucidate the interaction mechanism among plants,pathogen and the environment. } Minimize the loss of useful plants through application of the principles of plant disease prevention. } To prevent plant disease epidemics or to delay their onset until the harvest time is over. DISEASE Disease in a plant involves a number of harmful Physiological processes which leads to a lot of irregularities in the morphology and anatomy of the host. SYMPTOMS The altered and disadvantageous differences of the host from the normal plant are referred to as Symptoms of the disease. 1. Host : An organism that harbours or supports the activities of a parasite . 2.Suscept :An organism that is susceptible or prone to disease. 3.Susceptibility :It is the inability of a plant to resist the effect of a pathogen or any other damaging factor. 4.Parasite :It is an organism or virus existing in an intimate association with another living organism from which it derives an essential part of the materials for its existance. 5.Pathogen :A pathogen is an organism or virus capable of causing disease in a particular host. -
Angular Leaf Spot of Cucumber in Japan
Angular Leaf Spot of Cucumber in Japan YASUMASA WATANABE* and AKIRA OHUCHI** * National Institute of Agricultural Sciences (Yatabe,Ibaraki, 305 Japan) * Hokuriku National Agricultural Experiment Station (Inada, Joetsu,Niigata, 943-01 Japan) Cucumber angular leaf spot is one of the culture, Forestry and Fisheries organized a most prevalent diseases of cucumber (cucur co-operative research program "Studies on bit) in Japan. The affected fields covered the integrated control of bacterial diseases in 6,240 hectares in 1980, accounting for about cucurbits"23> which lasted four years from a half of the total cucumber-planted area in 1976 to 1979, in order to establish a combined cluding plastic house cultivation. cultural and chemical control procedure. The The first incidence of cucumber angular authors will describe outline of the results leaf spot in Japan was reported by Tominaga obtained in this research program. & TsuchiyaH> in 1957. Since Mukoo et al.OJ recognized its severe incidence in Kanto dis Causal bacterium trict in 1971, it has spread throughout Japan. The causal bacterium not only produces Ohuchi et al.O> examined more than one spotted lesions on cucumber leaves ( Plate 1) hundred isolates collected from affected cu but also affects cucumber fruit (Plate 2) , fol cumber plants which were distributed in the lowed by entire decay of the fruit. various parts of Japan and identified 110 The disease was so severe in cucumber isolates as Pseuclomonas syringae pv. Zachry growing districts that the Ministry of Agri- mans (Smith & Bryan 1915) Young, Dye & Plate 1. Typical symptom of cucumber angular leaf spot on leaf 113 isolates by needle pricking on cucumber fruit segments and incubating in moist chamber at 24 °C. -
Red Shoot Disease of Cranberry
Cranberry Pest Management Red Shoot Disease of Cranberry Red shoot, caused by the fungus Symptoms and spindly with red or yellow Exobasidium perenne, is a rela- leaves that are slightly more tively minor disease of the culti- Signs round than typical oblong cran- vated American cranberry Symptoms Þrst appear in the berry leaves (Figures 1Ð3). By (Vaccinium macrocarpon) and the spring on current yearÕs shoots mid summer the lower surfaces wild small cranberry (Vaccinium that occur singly or as a cluster of leaves become covered with oxycoccus). The red shoot fun- arising from a node on a buried white, powdery fungal spores. gus is related to the fungus that runner. Affected shoots do not Shoots wither after the fungus causes red leaf spot. Red shoot produce ßowers but rather are has shed its spores. Diseased has been reported in Wisconsin, shoots break off easily from the Massachusetts, the PaciÞc Northwest, and in the Atlantic maritime provinces of Canada. Red shoot is not an economi- cally important disease, and speciÞc control recommenda- tions have not been developed. However, the distorted, red or yellow shoots have sometimes been misidentiÞed as a weed, making growers think that an herbicide should be applied. The fact that red shoot is a dis- ease has been conÞrmed by tak- ing fungal spores from infected plants and inoculating them Figure1. Clusters of red shoot in a bed of ‘Searles’. The orangish-rust col- onto healthy plants; the inocu- ored shoots to the left are not affected by red shoot, but rather a different lated plants then developed red problem such as upright dieback.