2019 ASHS Annual Conference

Biochar (BC) can be an excellent alternative of peat moss as greenhouse media with similar effects on container plants. The objective of this study was to investigate the effects of pine bark biochar (PBC) and sugarcane biochar (SBC) mixed with peat moss at different rate (10%, 30%, 50% and 70% PBC with the rest being peat moss, or 10% , 30%, 50% and 70% SBC with 30% perlite and the rest being peat moss, by volume) on container tomato and basil growth, compared to control (70% peat moss and 30% perlite ) and a commercial mix. A phytotoxicity test was conducted with water extraction of each of the mixes and the deionized water was used as control. Only basil seeds were used and the final germination rates were used as indications of phytotoxicity. Tomato and basil seeds were sown in one of the mixes and their germination rates were recorded for 3 weeks. The seedlings were allowed to grow for another week and at the end of experiment, all seedlings were harvested to measure fresh weight and dry weight and the roots were washed and root length, root area, the number of tips were measured by using root scanner. The effects of biochar on tomato and basil vary among biochar types and rates. There was no difference among the mixes for the phytotoxicity test. There was no significant difference for tomato plants among the mixes on survival except for plants grown in 100% PBC, which had significant lower survival rate and for plants grown in 10% of PBC, which had significant higher survival rate compared to control. Basil plants grown in 100% SBC, 10% PBC, 70% PBC and 100% PBC had significant difference from control on survival. PBC can replace peat moss without addition limestone as greenhouse media amendment up to 70% and 50% for seedling production of tomato and basil plants.