Nitrogen fertilization and glyphosate doses as growth regulators in Esmeralda grass

Raíssa P. D. Gazola,Rodolfo de N. Gazola,Thiago de S. Celestrino,Regina M. M. de Castilho,Marcelo C. M. Teixeira Filho,Salatiér Buzetti

doi:10.1590/1807-1929/agriambi.v23n12p930-936

Raíssa P. D. Gazola, Rodolfo de N. Gazola + Show 4 more

Open Access

https://doi.org/10.1590/1807-1929/agriambi.v23n12p930-936

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Abstract

ABSTRACT Despite maintaining the green color in turfgrasses, nitrogen (N) fertilization affects shoot growth and, consequently, the frequency of cuts, the main factor in the costs of turfgrass maintenance. Therefore, this study aimed to evaluate N fertilization and the use of glyphosate as a growth regulator in Esmeralda grass (Zoysia japonica Steud.). The experiment was conducted in the field, from August 2014 to July 2015, using a randomized block design in a 5 x 4 factorial scheme with four repetitions and 20 treatments, namely: control (without N), 15 g m-2 of N in soil without foliar N; 30 g m-2 of N in soil without foliar N; 15 g m-2 of N in soil with foliar N (1% urea in 200 L ha-1) and 30 g m-2 of N in soil with foliar N combined with glyphosate doses (0, 200, 400 and 600 g ha-1 active ingredient (a.i.)). The N doses were split into five applications along the year. The following variables were evaluated: height, leaf chlorophyll index and foliar accumulation of nitrogen, phosphorus and potassium. Fertilization with 15 g m-2 of N in soil without foliar N application, split into five times along the year, was adequate for the turfgrass, while foliar fertilization did not promote benefits. The glyphosate dose of 400 g ha-1 a.i. was effective in reducing the growth of Esmeralda grass, without compromising its color and promoted less N, P and K accumulation in the leaves, reducing the height and dry matter production.

Highlights

Esmeralda grass is used in most of the Brazilian residential gardens (Godoy et al, 2012a), but there are still few studies on planted lawns (Dinalli et al, 2015), and fertilizer recommendations are subjective.The application of higher nitrogen (N) doses leads to a more intense green color in the lawns (Dinalli et al, 2015; Gazola et al, 2016)
The experiment was conducted in the field, from August 2014 to July 2015, using a randomized block design in a 5 x 4 factorial scheme with four repetitions and 20 treatments, namely: control, 15 g m-2 of N in soil without foliar N; 30 g m-2 of N in soil without foliar N; 15 g m-2 of N in soil with foliar N (1% urea in 200 L ha-1) and 30 g m-2 of N in soil with foliar N combined with glyphosate doses (0, 200, 400 and 600 g ha-1 active ingredient (a.i.))
In the 1st, 2nd and 5th evaluations, the highest values of Esmeralda grass height were obtained with the application of 6 g m-2 of N via soil and with foliar N application, which did not differ from 6 g m-2 of N via soil and without foliar N application

Summary

Introduction

Esmeralda grass is used in most of the Brazilian residential gardens (Godoy et al, 2012a), but there are still few studies on planted lawns (Dinalli et al, 2015), and fertilizer recommendations are subjective.The application of higher nitrogen (N) doses leads to a more intense green color in the lawns (Dinalli et al, 2015; Gazola et al, 2016). Esmeralda grass is used in most of the Brazilian residential gardens (Godoy et al, 2012a), but there are still few studies on planted lawns (Dinalli et al, 2015), and fertilizer recommendations are subjective. There is higher dry matter production and extraction of nutrients in Esmeralda (Backes et al, 2010) and Bermuda grass (Cynodon dactylon) (Lima et al, 2015), as well as N in St. Augustine grass (Stenotaphrum secundatum Kuntze) (Godoy et al, 2012b). Augustine grass (Stenotaphrum secundatum Kuntze) (Godoy et al, 2012b) This increases the cost of lawn maintenance (Backes et al, 2010; Godoy et al, 2012a), since more cuts will be needed, in addition to the replenishment of nutrients through fertilization. There is a need for alternatives for management, such as the use of plant growth regulators (March et al, 2013), and the ideal is the one which reduces height and dry matter production (lower nutrient export), without causing visible damage to the plants (Christoffoleti & Aranda, 2001; March et al, 2013)

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