Growth and yield of corn hybrids in response to association with Azospirillum brasilense and nitrogen fertilization

Abstract

Growth and yield of corn hybrids in response to association withAzospirillum brasilense and nitrogen fertilization 1 There is a growing interest in optimizing the positive effects of the association between Azospirillum bacteria and corn crop in order to reduce the use of nitrogen fertilizers. This study aimed to evaluate the inoculation efficiency of an A. brasilense-based commercial product in association with different rates of nitrogen fertilization in two corn genotypes. The experiment was arranged in a 2 x 2 x 5 factorial randomized block design, with four replications. The treatments consisted of two corn hybrids (30F53 and CD386); with and without inoculation with a commercial product based on A. brasilense and five nitrogen rates (0, 40, 80, 120 and 160 kg ha -1 ). The variables plant height, basal stem diameter, leaf area, shoot dry matter, leaf nitrogen content, length and diameter of the cob, weight of 100 grains and grain yield were evaluated. Inoculation with A. brasilense provided increases of 11 and 12% in leaf area and shoot dry matter, respectively. There were differences in the response of the corn hybrids for most variables and the increase in nitrogen supply provided increments in the growth and yield of corn.

Maize growth in response to Azospirillum brasilense, Rhizobium tropici, molybdenum and nitrogen

“…Pedrinho et al (2010), in a study on the activity of microorganisms in maize rhizosphere, observed phosphate solubilization and production of indole acetic acid (IAA) by bacteria of the genus Azospirillum. The increment of variables related to maize growth due to the isolated use of Azospirillum brasilense or combined use with N and/or other bacterial species has already been reported by Hungria et al (2010), Dartora et al (2013), Hahn et al (2013), Mazzuchelli et al (2014) and Marini et al (2015).…”

“…These growth variables are considered as determinant for the production of the plants, evidencing the beneficial effects of this microbial species. Marini et al (2015) and Quadros et al (2014) also reported that Azospirillum brasilense caused increase in the shoot dry matter of maize plants. However, Cunha et al (2014) and Morais et al (2015) did not observe increase in plant height or stem diameter in response to maize seed inoculation with Azospirillum brasilense.…”

Agronomic efficiency of inoculant based on Azospirillum brasilense associated with nitrogen fertilization at maize

“…it was found that 60 to 70% of the experiments had positive results. In this sense, the beneficial effects of inoculation with A. brasilense have already been reported in several studies in the literature (Dartora et al, 2013;Repke et al, 2013;Quadros et al, 2014;Costa et al, 2015;Marini et al, 2015;Morais et al, 2015), in addition to the increase in productivity, the characteristics that these bacteria have in synthesizing growth-related phyton-mones are shown in Figure, such as auxins, gibber-linins and cytokinins (Kuss et al, 2007;Perrig et al, 2007) and the availability of N 2 present in the soil in absorbable forms for plants.…”

“…In this line, inoculation of the seeds with A. brasilense increases foliar area and shoot dry matter by 12% on the foliar area and dry issue of aerial part (Marini et al, 2015). Costa et al (2015), showed an increase in plant height, dry stem and root mass, chlorophyll content, a thousand-grain mass, and final crop yield of the second crop.…”

Nutritional aspects of corn due to cover crops, nitrogen doses and inoculation with Azospirillum brasilense

“…It aims to nourish the plant adequately, minimizing losses and making the use of nutrients more efficient, especially nitrogen (N), phosphorus (P) and potassium (K), which are the most extracted nutrients from the soil by corn plants. According to Coelho and França (1995) and Von Pinho et al (2009), corn plants accumulate macronutrients in shoot dry matter in the following decreasing order: N>K>P>Ca>Mg>S. Given the high economic and environmental costs of the mineral fertilizer manufacturing process, agriculture faces the challenge of increasing crop production and reducing the use of fertilizers to make the agricultural system sustainable (Marini et al, 2015). In this context, it is necessary to seek other forms of supplying nutrients for crops, especially corn.…”