Rhizosphere Bacteria Biofertiliser Formulations Improve Lettuce Growth and Yield under Nursery and Field Conditions
Ziyu Shao,
Alexander Arkhipov,
Maria Batool,
Sean R. Muirhead,
Muchineripi S. Harry,
Xuan Ji,
Hooman Mirzaee,
Lilia C. Carvalhais,
Peer M. Schenk
Affiliations
Ziyu Shao
Plant-Microbe Interactions Laboratory, School of Agriculture and Food Sustainability, The University of Queensland, Brisbane, QLD 4072, Australia
Alexander Arkhipov
Plant-Microbe Interactions Laboratory, School of Agriculture and Food Sustainability, The University of Queensland, Brisbane, QLD 4072, Australia
Maria Batool
Plant-Microbe Interactions Laboratory, School of Agriculture and Food Sustainability, The University of Queensland, Brisbane, QLD 4072, Australia
Sean R. Muirhead
Plant-Microbe Interactions Laboratory, School of Agriculture and Food Sustainability, The University of Queensland, Brisbane, QLD 4072, Australia
Muchineripi S. Harry
Plant-Microbe Interactions Laboratory, School of Agriculture and Food Sustainability, The University of Queensland, Brisbane, QLD 4072, Australia
Xuan Ji
Plant-Microbe Interactions Laboratory, School of Agriculture and Food Sustainability, The University of Queensland, Brisbane, QLD 4072, Australia
Hooman Mirzaee
Plant-Microbe Interactions Laboratory, School of Agriculture and Food Sustainability, The University of Queensland, Brisbane, QLD 4072, Australia
Lilia C. Carvalhais
Center for Horticultural Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Ecosciences Precinct, Brisbane, QLD 4072, Australia
Peer M. Schenk
Plant-Microbe Interactions Laboratory, School of Agriculture and Food Sustainability, The University of Queensland, Brisbane, QLD 4072, Australia
Rhizosphere bacteria can provide multiple benefits to plants, including increased nutrient supply, pathogen/disease control, and abiotic stress tolerance, but results from pot trials do not always translate to field conditions. This study tested whether rhizosphere biocontrol bacteria can also provide plant growth promotion and how benefits can be provided at a commercial farm. Commercial lettuce seeds and plants were treated with rhizosphere biocontrol bacteria Bacillus velezensis UQ9000N, B. amyloliquefaciens 33YE, Brevibacillus laterosporus 4YE, and Pseudomonas azotoformans UQ4510An. 33YE increased the head diameter, plant height, and fresh weight of the Green Moon cultivar, while 33YE, UQ4510An, and UQ9000N increased the fresh and dry weight of Liston, a more heat-tolerant cultivar, via a single seed treatment or repeat root treatments under nursery and field conditions across different inoculation schedules and growth stages. Significant growth promotion was also demonstrated when inoculating field plants after transplanting (in particular for 33YE). Applications of these microbial biostimulants to lettuce seeds or plantlets potentially enable earlier transplanting and earlier harvests. Repeat inoculations using irrigation water and long-lasting formulations may further advance the benefits of these biostimulants as microbial biofertilisers for plant growth promotions in the field.
