Action specificity of chemical treatment and inoculation with Azospirillum brasilense in wheat seed on the crop initial growth

Abstract

The agronomic efficiency of the nitrogen-fixing inoculants or growth promoters depends on the growing conditions of the crops. One of the factors that may influence this response is the interaction between the bacteria present in the inoculant with the chemical treatment applied to the seeds. The objective of this study was to evaluate the influence of inoculation of wheat seeds with Azospirillum brasilense and its interaction with seed treatment on germination, vigor and initial growth of wheat plants of four cultivars. So, an experiment was carried out at the Federal University of Santa Maria, Santa Maria-RS. The experimental design was a completely randomized in a three-factorial (4x4x2), represented by the combinations between cultivar (FUNDACEP Bravo, OR/TBIO Quartzo, TBIO Itaipu e BRS 331), chemical treatment (1: Insecticide + Fungicide; 2: Insecticide; 3:Fungicide; 4: Witness without treatment) and Azospirillum brasilense inoculation (with and without inoculant). The determinations which were carried out were the following: emergence in beds, first germination test counting (vigor), germination, seedling length (root, aerial part and total), dry mass (root and aerial part). The responses to inoculants with Azospirillum brasilense are closely related to the cultivars used in the study. The treatment of seeds with fungicide and insecticide presented a phytotoxic effect, damaging the initial growth of the seedlings.

Growth promotion in wheat seedlings altered by conditions in the culture medium of Azospirillum brasilense

“…The results obtained in the present experiment reinforce the results reported by Ludwig et al (2018) and Munareto et al (2018) indicating the phytotoxic effect of chemical treatment on seedling germination and growth. The germination and vigor of seeds are reduced with the addition of products, live or synthetic, on the seeds (Fipke et al, 2019).…”

“…Among the alternatives for obtaining wheat seedlings with rapid growth and development, homogeneous and vigorous stand, can be associated with seeds having growth-promoting bacteria (Ludwig et al, 2018). Positive results have been observed with inoculation of wheat crop using Azospirillum brasilense (Galindo et al, 2019;Munareto et al, 2019;Zaheer et al, 2019).…”

Organic and Mineral Source of Nitrogen Associated With Azospirillum brasilense in Culture of Wheat

“…Besides, the addition of a carbon source activates the soil biota, favoring those more adapted to the environment, in this case the native ones. On the second hand, other factors can negatively contribute such as inoculation rate, soil physical-chemical characteristics, pesticides and also of the plant genotypes themselves (Ludwig et al, 2018). Perhaps the wheat cultivar used in this study (TBIO TORUK) was not efficient in this interaction with these bacteria since they, as growth promoters, depend on the production of plant hormones that are synthesized and stimulate root growth by increasing the water and nutrients absorption capacity, which reflects on a greater resistance to water and salt stress (Hungria et al, 2010).…”

Modificaciones en el crecimiento temprano de trigo (Triticum aestivum L.) en presencia de Azospirillum brasilense y de Pseudomonas psychrophila

“…A los cuatro DDS se realizó el primer conteo de plántulas emergidas, y a los ocho DDS, el conteo final (Ludwig et al, 2018;ISTA 2020). A los diez DDS, se midió el largo de las radículas, el peso seco aéreo y el peso seco de las radículas.…”

“…Se ha descrito que algunos de los factores que explican esta variabilidad se relacionan con el cultivar de trigo utilizado, la cepa de Azospirillum spp. aplicada y la cantidad de recursos disponibles que tienen las plantas para su crecimiento (Veresoglou y Menexes, 2010;Díaz-Zorita et al, 2015;Cassán y Díaz-Zorita, 2016;Pathak et al, 2016;Ludwig et al, 2018).…”