2018 ASHS Annual Conference

Biostimulants, formulated products of various biological origins, have been considered as innovative tools to improve plant productivity by enhancing nutrition efficiency, abiotic stress tolerance, and quality parameters for crop production. Among all biostimulant groups, plant-derived protein hydrolysate group have gained in popularity due to its effectiveness. Plant propagation by stem cuttings is a general method for the commercial production of many greenhouse crops, with auxin being the main rooting hormone. The aims of this study were to identify the biostimualant action (hormone like activity) on adventitious rooting of cuttings and to determine its ideal concentration for the maximum rooting responses of cuttings. A biostimulatnt ‘Quik-Link’ containing lignosulphonate and protein hydrolysates derived from legume seeds was utilized in the cuttings of three different plant species, basil, tomato, and chrysanthemum. Unrooted cuttings of the plant species were either purchased from a commercial source or taken from stock plants grown in the greenhouse. 10-20 replicates of each plant species were treated with either biostimulant at five different concentrations (0, 0.1, 1, 5, and 10 g/L), or rooting hormone ‘Dip’N Grow’ at five different concentrations (0ppm, 100ppm, 200ppm, 300ppm, and 500ppm) for comparison. The cuttings were then planted in a propagation tray filled with soilless media and placed under intermittent mist where optimum temperature, humidity, and lighting were provided for rooting. Maximum rooting occurred in 3 weeks and percentage of rooting, root growth, and shoot growth were measured. The results demonstrated that the biostimulant showed auxin-like and gibberellin-like activities, noticeably increasing both root and shoot growth. It significantly enhanced the number of root and volume, and root dry weight, as well as stem length and shoot dry weight. Overall, plant cuttings treated with 5 g/L of the biostimulant showed the maximum effectiveness in adventitious rooting. The findings suggest that the treatment of unrooted cuttings with the biostimulant can significantly improve adventitious rooting in basil, tomato, and chrysanthemum. Interestingly, it was also found that the biostimulant can perceptibly enhance the number of roots in a different way unlike auxin.