Field performance of a seed treatment with Azospirillum brasilense on corn productivity

DÍAZ ZORITA, M.; MICUCCI, F.G.; FERNÁNDEZ CANIGIA, M.V.

Quirama, Medellín

Workshop; PGPR. 9th International and 1st Latinamerican PGPR Workshop. "Returning to our roots"; 2012

Univ. Antioquía- Univ. EAFIT- Uiv.Auburn - Univ.Nac. de Colombia- Corpoica- Soc. Colombiana de la Ccia del Suelo

The beneficial effects of inoculating with Azospirillum brasilense on the early growth and productivity of cereals crops have been widely described. But, the extensive use under regular production systems is limited because of scarce documented field applied trials. The objective of this study was to quantify the response of corn (Zea mays L.) crops to the inoculation of a liquid formulation containing A. brasilense INTA Az-39 strain under regular dryland extensive production systems in several regions of South America. The study was performed between 2002 and 2011 evaluating treated and non-treated crops in 298 experimental locations from Argentina, Bolivia, Brazil, Paraguay and Uruguay. In general, the crops treated with A. brasilense showed a greater vegetative growth with a greater shoot dry matter accumulation (7.9 %) and also a greater number of grains at harvest (4.3 %). No significant differences on single grain weight were described between the treatments. In 80.4% of the sites, the corn grain yield response to the A.brasilense treatment was greater than 50 kg ha-1 and it provided a mean grain response of 468 kg ha-1 (5.6% above the untreated control). The inoculation responses were greater under stressful conditions during the early growth of the crops or in the absence of N fertilization practices. We conclude that the on-seed treatment with this liquid formulation can enhance corn growth and yields under extensive production conditions complementing the best agronomical management practices recommended for each of the studied regions.