Abstract

                                The importance of plant diseases as factors responsible for limiting crop production cannot be overestimated. Crop diseases have heen recorded from the earliest times and have exercised a profound influence on human affairs. In India, the losses caused by plant diseases are enormous and there is no doubt, that if adequato measures are taken to keep them in check, the level of our crop production can be considerably increased. In the year 1946, the rust disease of wheat was responsible for almost wholesale destruction of the crop throughout the country, cultivators finding it difficult to gather even enough seed for their next sowing. The blast disease of paddy which breaks out off and on in an epiphytotic scale in the districts of Tanjore, Nellore and Chittoor has been known to cause damage extending up to 70 percent in certain years.

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