Tillering and biomass partitioning of Mombasa grass under nitrogen fertilization during regrowth

Américo Fróes Garcez Neto,Janielen Da Silva,Tiago Machado Dos Santos,Kátia Fernanda Gobbi

doi:10.1590/s1516-35982012000800004

Abstract

Biomass partitioning in forages is highly variable during plant development and with the rate of nutrient supply. This study was carried out with the objective to evaluate the tillering pattern and biomass partitioning of Mombasa grass (Megathyrsus maximus cv. Mombaça) subjected to rates of nitrogen (N) during regrowth. The treatments consisted of three weekly rates of N: control (without N supply), 25 and 50 mg dm-3 of N, which were evaluated by 1, 2, 4, 8, 16 and 32 days after defoliation. The design was of completely randomized blocks in a 3 × 6 factorial arrangement with three replicates. The number of tillers was measured and harvesting and weighting of the following morphological components were performed: leaf (leaf blades), pseudostem, stem base and root. Interaction between N rates and regrowth times was found for all variables analyzed. The N supply increased the number and weight of tiller (up to 117.3 and 167.6%, respectively), as well as the shoot dry matter yield of Mombasa grass. That effect was most significant particularly at 32 days of regrowth. Among the treatments receiving N supply, the highest N rate was more significant to leaf and shoot yield only after 6-11 days of regrowth. High N supply must be applied to Mombasa grass only after that time and the biomass harvested between 24-28 days of regrowth.

Highlights

Most of the milk, meat and wool produced in Brazil come from cattle raised on pastures
High N supply must be applied to Mombasa grass only after that time and the biomass harvested between 24-28 days of regrowth
There was no significant effect of number of tillers on the treatment which was not supplied with N

Summary

Introduction

Meat and wool produced in Brazil come from cattle raised on pastures. It is expected that the improvement in the livestock yield in this region be increased with the use of high-yielding forages (Elyas et al, 2006; Alencar et al, 2010). Mombasa), have shown high potential for dry matter yield supporting higher stocking rates and animal performance (Jank, 1995). Their high yields depend on adequate soil fertility, so they can grow faster after successive and frequent defoliations (Gomide, 1993). Knowledge of the nutritional factors that influence the growth and development of forages is of fundamental importance to the establishment, management and persistence of forages (Belarmino et al, 2003)

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Conclusion