Bioinoculants for sustainable production of saffron spice and by-products: overview and prospects

The dried red stigmas of Crocus sativus L. are the precious spice known as saffron. Also called “red gold”, saffron has the highest price among spices due to the intense manual labour required for its production. Both the spice and violet tepals (floral waste) contain bioactive compounds with health-promoting properties. In the last decades, saffron production in European countries has seriously decreased, mainly because manual labour costs have increased and the technology for its cultivation has not progressed. Its production is also challenged, e.g. by climate change and diseases. To improve the profitability of saffron, sustainable practices could be adopted to enhance the quality, productivity, and value of saffron products; inoculants of beneficial microorganisms, such as arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR), and industrial application of the tepals as a valuable by-product have been proposed. Recent studies on the use of bioinoculants on saffron have stated that they can limit the application of agrochemicals and improve productive and quality characteristics of this plant. Greater homogeneity in the approach to this type of study is necessary as it would help to make comparisons between bioinoculants and find optimal options for saffron cultivation.