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| Author(s): |
Raíssa Pereira Dinalli Gazola
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Ilha Solteira. 2017-05-10. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Engenharia. Ilha Solteira |
| Defense date: | 2017-03-31 |
| Advisor: | Salatiér Buzetti; Regina Maria Monteiro de Castilho |
| Abstract | |
Nitrogen fertilization provides, in addition to nutrition, the maintenance of intense green color in ornamental turfgrasses, necessary underesthetic view point. However, nitrogen (N) increases the shoots growth and, thus, the frequency of cuts, the main factor in the cost of turfgrasses maintenance. In this context, this study aimed to evaluate nitrogen fertilization (via soil and/or foliar) and the use of rates of glyphosate in zoysiagrass (Zoysia japonica Steud.) to reduce growth and maintain the visual quality (intense green) and good nutritional quality. The research was conducted at the Experimental Station of UNESP, Ilha Solteira/SP, from August/2014 to February/2017, on an Ultisol. It was used a randomized block design with 20 treatments arranged in a factorial scheme 5 x 4 with four replications and 10 m2 per plot. The treatments was: control (without N), 15 g m-2 of N in the soil without application of foliar N; 30 g m-2 of N in the soil without application of foliar N; 15 g m-2 in the soil with foliar application of N (1% urea) and 30 g m-2 of N in the soil with foliar application of N (1% urea) combined with four rates of glyphosate (0, 200, 400 and 600 g ha-1 active ingredient (a.i.)). N rates in the soil were split in five times during the year and, therefore, corresponded to 3 and 6 g m-2 of N at each application, respectively, for the rates of 15 and 30 g m-2 of N. Were evaluated: the chemical attributes of the soil, height and dry matter of leaves, leaf area, LCI (leaf chlorophyll index), the chlorophyll a and b, the digital image analysis and the percentage of phytotoxicity of the shoot, beyond the occurrence of weed species and number of inflorescences, as well as the concentration and accumulation of macro and micronutrients by leaves of turfgrass and log-isometrics balance of macronutrients in the leaves and cationic balance in the soil (isometric log ratio - ilr). It was being also assessed the root system (dry matter and macro and micronutrients in roots + rhizomes). Ten evaluations (cuts) were carried out. The levels of K in the soil increased with the glyphosate rates. There was higher dry matter of the roots + rhizomes when N fertilization and decrease of these values with the doses of herbicide. The greater amount of N via soil, with or without N via foliar, resulted in greater growth of the zoysiagrass, being reduced with the dose of 600 g ha-1 of a.i. of glyphosate. However, this herbicide rate was not aesthetically ideal - green color. It was concluded that the fertilization with 15 g m-2 of N in the soil without foliar N, split in five times during the year, provided visual and nutritional quality of the grass, and the rate of glyphosate of 400 g ha-1 a.i. was effective in reducing zoysiagrass growth, did not sacrifice its coloration and provided less accumulation of macronutrients in the leaves, reducing the need for replenishment by fertilization. (AU) | |
| FAPESP's process: | 14/02449-8 - Nitrogen fertilization and rates of glyphosate as growth regulators in zoysiagrass |
| Grantee: | Raíssa Pereira Dinalli Gazola |
| Support Opportunities: | Scholarships in Brazil - Doctorate |