Supplementing organic biostimulants into growing media enhances growth and nutrient uptake of tomato transplants

- Tomato transplants growth and nutrient uptake in growing media was studied.
- Adding humic acid (HA) + crushed maize grain (CMG) improved shoot and root traits.
- Adding HA + CMG improved relative water contents and membrane stability of transplants.
- N, P and K transfer ratios of transplants also increased with HA + CMG.
- CMG can be organic component of standard growing media for horticultural crops.

Addition of plant growth biostimulants may have great impact on physical characteristics of growing media and plant growth. The present study evaluated response of tomato (Lycopersicon esculentum, Mill.) transplants for growth, some physiological attributes and nutrient uptake to three different growing media containing peat (P) and vermiculite (Verm) supplemented with crushed maize grain (CMG) and/or humic acid (HA) for two growing seasons. Results showed that none of the media used affected seedling emergence and survival percentage, however, maximum increase in stem diameter and root system volume was observed when media supplemented with CMG and/or HA. Similar response was observed for transplant height, number of leaves and total leaf area per transplant, leaf and root dry weight and total dry weight per transplant. Maximum relative water contents (RWC) and membrane stability index (MSI) with reduced electrolyte leakage was found for HA + CMG supplemented media followed by HA free media but with CMG. Highest increase in N, P and K transfer ratios was also found in tomato transplants grown with HA + CMG, albeit N transfer ratio was statistically similar for CMG added with or without HA. In crux, supplementing HA together with CMG as plant biostimulant rich in minerals, hormones and secondary metabolites into standard growing media had stimulatory effects on tomato transplants, therefore, can be used as organic component for sustainable production of horticultural transplants.