Biostimulants promote plant vigor of tomato and strawberry after transplanting

Transplanting shock results in plant growth retardation and developmental delay, and sometimes seedling death. Robust root growth is then critical for transplanted seedlings to survive and re-initiate the growth and development within a short period. Biostimulants have beneficial effects on fostering plant growth and development mainly due to complementary mechanisms. In the present study, we chose three different biostimulants including Radifarm, Acadian and ScanPro to investigate their roles in regulating post-transplantation growth of tomato (Solanum lycopersium L.) and strawberry (Fragaria x ananassa Duch.) seedlings. We observed significant promotion effects of Radifarm on tomato and strawberry underground tissue growth including increased root diameter, surface area and root volume at the early stage after transplanting. Acadian and ScanPro had more significant effects on the promotion of aboveground than underground tissue growth after transplanting including enhanced fresh and dry weights, and plant height. Our clustering analyses and principle component analyses further demonstrated that different biostimulants display distinct impacts on seedling growth, which depends on developmental stages, tissue types and plant species. Specifically, tomato had better responses than strawberry to all three biostimulants, which is probably due to its different root architecture. Our findings reveal that biostimulants facilitate plant post-transplantation growth recovery in a plant-organ specific mode, which suggests the combined application of different biostimulants would achieve better effects.