Influence of cutting height and nitrogen fertilization on plant height and tiller production of guinea grass (Panicum maximum Jacq) pasture

A study was conducted at Nsukka, Nigeria to determine the effects of cutting height and N fertilizer application on the growth and tiller production of Panicum maximum pasture. The experiment was a 3 × 3 factorial laid out in a randomized complete block design with three replications. Treatments comprised three cutting height (5, 10 and 15 cm) and three levels of nitrogen (0, 200 and 400 kg N ha-1) resulting in nine treatment combinations per block. Plant height was significantly (P < 0.05) increased by 34 and 56% in 2008 and 2009, respectively, when cutting height increased from 5 to 15 cm. Grass tiller number per square metre varied inconsistently among the cutting heights at different harvest periods in both years. Grass height remained statistically similar among the nitrogen rates in both years but increased significantly (P < 0.05) with fertilizer N application compared with the control at some periods in both years. Grass tiller number obtained in 2008 from plots cut at 10 cm stubble height with 400 kg N ha-1 was significantly (P < 0.05) higher than those cut at 5 cm with zero N application. Cutting height × fertilizer-N interaction effect on plant height was significant (P < 0.05) in all the periods in both years.   Key words: Grass height, stubble height, tiller population, fertilizer N.