Effects of Single and Combined Inoculations with Azospirillum brasilense and Trichoderma harzianum on Seedling Growth or Yield Parameters of Wheat (Triticum vulgaris L., Giza 168) and Corn (Zea mays L., Hybrid 310)

Abstract

Inoculation of wheat and corn grains with formulations of Azospirillum brasilense significantly increased seedling growth parameters of wheat and corn compared to untreated controls. Inoculation with Azospirillum and supplemental Trichoderma harzianum free or coimmobilized in calcium alginate resulted in significant increase in all plant growth parameters in addition to improving plant nutrient-content [phosphorus (P), potassium (K), and calcium (Ca)]. Grain treatments with T. harzianum alone or in a combination with A. brasilense were protected from invasion by Fusarium in a pot experiment. Nitrogen (N) fixation was investigated by A. brasilense free or double inoculated with T. harzianum in soil amended with different C-sources; also, phosphate solubilization was tested by these two organisms. Single and double inoculation with A. brasilense and/or T. harzianum improved wheat yield growth parameters in addition to seed protein; therefore, immobilized and coimmobilized formulations could be used as biofertilizer and biopesticide, and might be recommended to avoid the extensive use of the agrochemicals.

Keywords:

• Azospirillum brasilense
• biological control
• calcium alginate
• corn
• free and immobilized cells
• nitrogen fixation
• plant growth promotion
• Trichoderma harzianum
• wheat