Effects of biochar on pepperoncini (Capsicum annuum L cv. Stavros) germination and seedling growth in two soil types

Abstract

Biochar is a solid material obtained from the carbonization of biomass. The effect of biochar on the germination and seedling growth of pepperoncini pepper (Capsicum annuum L. cv. Stavros) was studied under controlled growth chamber conditions in two experiments. The substrates in the pre-test experiment (first experiment) were 2%, 4%, 6%, 8%, and 10% biochar (at 24°C or 28°C), while in the second experiment they were acidic (pH 6.1) or alkaline soil (pH 7.2), with or without biochar at 24°C. Three replicates (Petri dishes) for each treatment were placed at random in a growth chamber for 12 days at a 16/8h light/dark photoperiod, 12 klx light intensity and 80% relative humidity. In biochar substrates the seed germination percentage in H2O-control was high at 24°C and low at 28°C. At 28°C it was also increased (4°C) and it was higher than the corresponding one in the H2O-control. At both temperatures (24°C and 28°C) there was a tendency for increased height growth. The percentage of seed germination in acidic soil substrates was low (42%), while in alkaline soil substrates high (82%). All biochar applications in acidic soil substrates increased the seed germination percentage, which varied between 53% and 67%. Biochar application in alkaline soils substrates did not influence seed germination. Seedling height in acidic soil substrates was 0.15cm, while in alkaline soil substrates it was 1.63cm. Biochar application in acidic soils increased the seedling height, while in alkaline soils it was reduced when compared to the control.