Harmfulness of economically important diseaes in sugar beet
2008
Tanova, K., Institute of Agriculture, Shumen (Bulgaria)
During the 19952004 period at the Agricultural Institute Shumen studies have been conducted researches on the harmful action of the economically important diseases: powdery mildew, Cercospora leaf spot and Phoma leaf spot on the quality of the sugar beet raw material. On an infectious background of the agents of the diseases field trials were made by the block method, with variants “plants with symptoms of the respective disease (diseased)” and “plants without symptoms, preserved with fungicides from the diseases (healthy)”. While harvesting the trials, samples were taken for technological analysis, made by a modified method. Soluble ashes, harmful nitrogen, potassium and sodium were analyzed. The yield of roots, the sugar content and dry matter were determined in the trial with the agent of Phoma leaf spot. As a result of the analyses the following conclusions are made: The agents of powdery mildew and cercospora leaf spot increase the content of soluble ashes, respectively with 0.06% and 0.09%; of the harmful nitrogen with 1.8 mg and 0.98 mg, and decrease the content of potassium, respectively with 0.59% and 0.45%; The agent of Phoma leaf spot decrease the root yield up to 16.3%, and the sugar content with 1.2 points.
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