Manganese content of certain Connecticut soils and its relation to the growth of tobacco
1932
Jacobson, H.G.M. | Swanback, T.R.
The above report gave evidence to the following conclusions regarding Connecticut soils: A high amount of active manganese in a soil was toxic to tobacco and manifested itself by producing plants with definite abnormalities. Manganese toxicity symptoms occurred in tobacco plants when grown in solution cultures when the concentration of manganese was as low as 1 p.p.m. When tobacco was grown in sand cultures, the application of 80 p.p.m. of manganese indicated toxicity in early stage of growth. In field tests 486 pounds of manganous sulfate to the acre failed to cause injury, which was probably due to the degree of acidity in the field soil. Tobacco is a luxury feeder of active manganese. Increased acidity of soils resulted in larger amounts of active manganese present and a greater intake of manganese by tobacco plants. Total and active manganese content decreased in amount toward the east of Connecticut. Leachates (water-soluble manganese) increased in manganese content with acidity increase. The greatest percentage of manganese was found in the middle leaves and the least in the upper leaves of a manganese-injured tobacco plant.
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