Manganês na nutrição e na produção de massa seca do capim-mombaça

Abstract

There are few studies that relate the micronutrient manganese nutritional status and production of fodder. The objective was to evaluate the application of manganese in the nutrition and growth of Mombaça grass. The completely randomized design was used with five manganese levels (0, 15, 30, 60, 120 mg dm -3) and four replicates. Each experimental unit consisted of a pot filled with 3.5 dm -3 of soil from Oxisol (Mn = 0.6 mg dm -3), containing four plants. Two harvests were set, the first 44 days after sowing and the second 38 days after the first cut. The concentration of manganese in the soils, the manganese content of leaves, number of tillers, plant height, shoot dry mass in each slice and the root system of Mombaça grass were evaluated. The applied rates of manganese resulted in increased accumulation of Mn in the plant, and there was an increase in dry mass of Mombaça grass, with maximum production, obtained from derivation, of 5.9 and 6.3 g plant -1 for levels of 121 and 71 mg dm -3 of Mn in the first and second cut respectively. The Mombaça grass has showed high manganese's tolerance, the critical level of toxicity was 841 mg kg -1 in the second cut.