Plant biostimulating effects of the cyanobacterium Nostoc piscinale on maize (Zea mays L.) in field experiments

Biostimulants, when applied to plants in small amounts, increase crop yield and plant tolerance to abiotic and biotic stress. They play an important role in the development of new environmentally sustainable technologies. The aim of the current experiment was to investigate the potential of a cyanobacterium strain (Nostoc piscinale) to improve the growth, grain yield and stress tolerance of maize (Zea mays SY Zephir hybrid). Field trials were established at two sites. Freeze-dried biomass of N. piscinale resuspended in tap water (1g/L DW) was applied as a single foliar treatment (400 L/ha) at the V6-V7 phenological stage. Number of leaves, chlorophyll content, relative water content (RWC%) and free proline content were measured weekly. Grain yield, yield components and grain protein content were measured at harvest. N. piscinale treated maize had significantly earlier development in the vegetative growth stages with a higher number of leaves. Chlorophyll content (SPAD value) was significantly higher in the treated plants during the reproductive stages. There was little difference in the RWC and proline content compared to control plants. Faster vegetative growth and higher chlorophyll content in the cyanobacterium treated plants meant great photosynthetic light absorption over a longer period of time, resulting in significantly higher grain yield (6.5% and 11.5% at the two production sites) and increased grain protein content. Grain yield was significantly influenced by cob length and thousand grain weight. In conclusion, it was proved in field trials conducted in two different regions in Hungary that a single foliar application of a cyanobacterium-based biostimulant can contribute to crop production in a sustainable and environmentally friendly manner.