Abstract
Plant biostimulants can enhance crop nutrition status, stress tolerance, yield and quality in environment-friendly manner. The aim of this study was to determine the effect of an algae and bacteria preparations on the yield and nutritional parameters of leaf and romaine lettuce cultivated for spring and summer crop. The application of a combined biostimulant consisting of plant growth-promoting bacteria (Bacillus licheniformis, Bacillus megatherium, Azotobacter sp., Azospirillum sp., and Herbaspirillum sp.) and fresh water algae (Chlorella vulgaris) was done by watering the lettuce every 14 days, and a determination of the fresh weight, total antioxidant capacity, and total carotenoids content was performed. The result revealed that the application of bacterial-algal preparation significantly affected the plant weight of both romaine and leaf lettuce in spring and summer seasons. The highest increase in the weight of romaine lettuce reached 18.9% in the spring crop, while in the case of leaf lettuce, biostimulant treatment led to a 22.7% higher weight in the summer crop. Total antioxidant capacity and total carotenoids content showed increased values in the summer crop of romaine lettuce, while for the leaf lettuce there were no differences between treatments. Therefore, the positive effect of bacterial-algal treatment on lettuce yield, total antioxidant capacity and total carotenoids confirm that it could be applied for improving romaine lettuce yield quality and quantity, especially in stress, summer conditions.
Highlights
Plant biostimulants, described as any substance or microorganism applied to plants with the aim of enhancing nutrition efficiency, abiotic stress tolerance, and/or crop quality traits, have a steadily growing market, according to market analysis reports (Marketsandmarkets.com, 2014)
Bacteria interactions with plants can influence the supply of nutrients, increase nutrient use efficiency, induce disease resistance, enhance abiotic stress tolerance, and modulate morphogenesis through plant growth regulators (Ahmad et al, 2008)
The leaf number, width, and length of treated lettuces were slightly lower than the control plants in the first and third crop seasons. These results indicate that the application of Bacillus licheniformis alone did not promote the growth of lettuce in any crop season
Summary
Plant biostimulants, described as any substance or microorganism applied to plants with the aim of enhancing nutrition efficiency, abiotic stress tolerance, and/or crop quality traits (du Jardin, 2015), have a steadily growing market, according to market analysis reports (Marketsandmarkets.com, 2014). Microorganisms and their metabolites that are capable of enhancing soil fertility, crop growth, and/or yield could provide an alternative to agricultural chemicals (Von Bennewitz and Hlušek, 2006). Microalgae extracellular enzymes can transform nutrients to more bioavailable forms that improve nutrient availability for both soil microflora and plants Examples of this are the phytohormones produced by freshwater algae, which can directly affect the physiological processes, morphogenesis, reproduction, rhizogenesis, and growth of cultivated plants (Tarakhovskaya et al, 2007). Bacteria interactions with plants can influence the supply of nutrients, increase nutrient use efficiency, induce disease resistance, enhance abiotic stress tolerance, and modulate morphogenesis through plant growth regulators (Ahmad et al, 2008)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
