1 Components of plants disease management
Transcript
Hello! I welcome you to the second week of this course. In this particular week we’ll be talking about principles of plant disease management. Initially we will be talking about the components of plant disease management and then we will be discussing each component separately in the subsequent talks. So let us start with the components of plant disease management. So traditional principles of plant Disease Control implies to certain principles and those are Avoidance then Exclusion, Eradication, Protection Resistance and Therapy. So what are these terminologies? Avoidance is prevention of disease by selecting a time of the year or a site where there is no inoculum or where environment is not favorable for infection. So we can avoid the occurrence of the disease by opting for a site or time of an year to avoid the disease so that the susceptible condition of the host does not contact with the favorable environmental condition of the pathogen. Exclusive means prevention of entry of the inoculum. Here we can take certificate sheets because certified sheets are free from infested pathogen infestation and thereby we can eradicate the pathogen from entry into a new area.
Next is eradication which is elimination basically by destroying and in activating the inoculum. We can eradicate the pathogen by eliminating, destroying and in activating the inoculum that is present on the plant bodies. Protection basically it is the prevention of infection by means of a toxicant which is normally a chemical compound. So protection is the application of chemical toxic compounds to prevent infection by a pathogenic organism. Resistance it is the utilization of cultivars which have resistance towards certain races or certain pathogens and this is a inherent characteristics of the particular plant variety. Then Therapy – it is basically curing of the plants after an infection has been established so these are the traditional principles which are followed for plant disease control. The principles are basically in absolute term can be defined in excluding, preventing and eliminating that imply a goal of zero disease. So plant disease control in this sense is practical and in most cases is not even possible. Indeed we need not eliminate a disease we merely need to reduce its progress and keep disease development below an acceptable level. This is the actual goal of our plant disease control. Very hardly we are able to eradicate or control the pathogen rather we manage the pathogen to a level where the economic injury level is not there. So this is the objective of plant pathologist or crop protectionist to attain in their longer run. So integrated disease management what it is basically? So Integrated Disease Management (IDM) is the selection of a variety of control methods based on economic ecological and social consequences. So it integrates several practices considering the economical, ecological and social aspects of plant disease management. IDM practices remove all alter conditions that attract conducive to pathogens infestations and therefore IDM can better cure existing infections and prevent future ones.
So IDM basically gives us the opportunity to lower down the pathogen infection in a cumulative way. So IDM have different components and among the major components they are Agronomical, Biological, Host-resistance, Physical, Chemical and certainother control measures that depends on the particular pathogen. So agronomicalpractices includes cultural practices like ploughing, rowing and many other practices that helps us to reduce the inoculum level from the field. Similarly biological is the implications of or applications of biological organisms for management of or lowering down the inoculum of pathogenic populations. Host resistance is the inherent characteristics of a particular crop variety that poses resistance against the infection or infestations of the plant pathogens. There are different physical methods, chemical methods and other techniques that are used to achieve the IDM successfully. Now what is the necessity to develop IDM practices because IDM utilizes the Best Management Practices to reduce plant disease with least disruption to the environment. We all know that chemicals are posing a serious threat to the environment and because of this serious threat to the environment every life-form including human being are getting affected. So IDM basically integrates the best management practices to deal with the pathogen. Considering the environment health condition is not deteriorated further from the existing one. It combines best scientific research output with practical application. So IDM is a concept that is developed or that has come out with a lot of research activities and only the best practices are adopted for IDM practices. It also protects against hazards to human, animals, plants and the environment which is not possible with the chemical management. So IDM is the most preferred way of tackling plant pathogens and that is the way ahead also to go for future Plant Disease Management practices. Now coming to the Principles of IDM.
What are the Principles of IDM? IDM allows tolerable disease development in contrast to the chemical disease management IDM practices allowed a little amount of disease but this amount of disease does not cause economic damage to the growers. Similarly, IDM utilizes natural control measures which is very very significant. It collectively integrates all the natural resources to manage the disease or the pathogen in comparison to the absolute use of chemical compounds. It also considers the environment and the natural ecosystem which is most important because when we apply only synthetic chemicals we all know that it harms or it pollute the environment. So IDM principles mostly focus to save or to protect the environment at the same time to tackle the plant pathogen or plant diseases. So what are the Implications of IDM then? So simultaneous management of multiple pathogens. So IDM practices is although targeted only one pathogen at a particular time but these practices include all components in a way that it also tackles some other pathogens which may be present in that particular area or in that particular field. So regular monitoring of pathogen effects and their natural enemies an antagonists is also a part of the IDM practices. So it also help us to become aware about the available diseases that are around in the particular area though monitoring is a very important component of IDM practices. Similarly, use of economic or treatment thresholds when applying chemicals. IDM practices does not recommend to advocate to exclude chemical practices but IDM incorporates chemicals to only in a limited manner. So that the limited amount of chemical applications does not harm the environment in contrast to the absolute application of chemical pesticides. So integrated use of multiples and suppressive tactics is also a part of principles of IDM. So IDM also integrate multiple and suppressive tactics. So that helps us to minimize the load of chemical compounds in management of plant pathogens. So what are the difference between the Traditional and IDM practices? So IDM practices basically required a greater knowledge. So unlike traditional practices which mostly go with one particular type of management strategy IDM practices, integrate a number of strategies and therefore it requires a greater knowledge of the different techniques. Similarly, it utilizes less toxic and more targeted techniques and that is why it is more preferred because the IDM principles based on non toxic or less toxic methods in comparison to the traditional disease control tactics. So that is why IDM practices are more effective, they are they cost less and effective for a longer time, which is also very important. At the same time it poses less risk in terms of development of resistance by pests and pathogens because, IDM utilizes multiple tactics to suppress a pest or pathogen. Then it also requires collective effort to realize its potential. This is another challenge for IDM practices. It is mostly successful in those places where it is taken as a community rather than a single person effort. So whatever the optional control measures that are included in IDM practices. It includes cultural, physical, biological and chemical as well. So cultural practices includes sight and plant selection and sanitation. Physical methods include pruning, mulching, barriers and weeding. Biological matters include applications or introduction of microparasites, hyper parasites and antagonists and Chemicals include application of insecticide, fungicide, herbicide and so on. At the same time IDM practices target to prevent, avoid, monitor pathogens and suppression of pathogens. So all these tactics are integrated in IDM practices stepwise for successful management of a plant pathogen. Now what are the terms, strategies and tactics defined? In dictionary language they both term look similar Strategies and Tactics. But if we just focus on these two term we will come out with the objective that strategy is reaching of a particular objective. This is what we call it as strategy. Whereas, specific means of implementing a given strategy is called tactics. So, this is the difference between the terms strategy and tactic strategy is reaching of a particular objective and how we are reaching that objective is the tactic. So tactics for reduction of initial inoculum based on again the principles of plant disease components Avoidance, Exclusion Eradication, Protection, Resistance and Therapy. So all these principles of traditional plant disease management is important for reduction of initial inoculum. Similarly, at the same time if we talk about ‘Reduction of Infection Rate’ then again all these principles of Avoidance, Exclusion, Eradication, Protection, Resistance and Therapy. This all apply to concept of reduction of infection rate as well. But when we talk about Tactics for Reduction of the Duration of the Epidemic. So here mostly two principles of plant disease management applies that is avoidance and exclusion. So ultimate objective is the reduction in pathogen suppression. But how we are going to achieve it, is dependent on the tactics that we are adopting to manage to incorporate different practices. So altogether we can say that there are different components of Plant Disease Management and these components has to be applied tactically to reach a permanent solution or to at least to a acceptable solution for plant disease management where inoculum load is reduced, rate of infection or rate of spread is reduced along with the duration of epidemic can be lowered down. So these principles are very very important and these are essential component for Plant Disease Management and these needs to be incorporated in a tactical manner to IDM practices of a particular pathogen which has to be managed.
Thank you
