Mineral nutrition of tropical forrag grasses III: macronutrients deficiencies in millet plants

Abstract

Seeds of Pennisetum americanum cv. Bulk 1 were sowed in pots containing fine quartz as substract and moist with water several times a lay. Two days after germination the young plants were irrigated twice a day with complete nutrient solution diluted (1:5) during 22 days. After these period the pots containing each 3 plants were percolated with distill water several times. After these period the treatments began and consisted of: complete solution, -N, -P, -K, -Ca, -Mg, -S. The nutrient solutions were changed every 10 days. With the appearence of the bad nutrition symptoms the plants were harvested with 52 days old, died, weighed and analyzed for the elements by the conventional methods. The authors concluded: The omission of N, P and K from the nutrient solutions reduce the dry weight of the plants. The omission of N, P, K and Mg from the nutrient solutions prevent the formation of ears by the plants. The range in dry matter from normal and leaves showing deficiency symptoms are: N% - 3.21-2.07; P% - 0.38-0.09; K% - 2.19-0.54; Ca% - 0.52-0.16; Mg% - 0.48- 0.04; S% - 0.24-0.12. A clear picture of the visual symptoms of the deficiencies was obtained.