Effects of Biochar Substrate and Microbial Inoculation on the Development of Raphanus sativus L. 

The use of substrates combined with biochar has been highlighted in agricultural and horticultural production, including the cultivation of Raphanus sativus L. (radish), due to the benefits in water retention, nutrient supply and stimulation of root development. This study evaluated the growth and development of radishes under different combinations of substrates with biochar, with or without microbial inoculation. The experiment was carried out between November 2024 and January 2025, in a greenhouse with automatic temperature control (18-42 °C) at the Federal University of São Paulo, São José dos Campos Campus. The treatments included: A) Substrate with biochar (SB-control); B) Substrate (S-control); C) Substrate with biochar inoculated with MELRC (SBI-MELRC); D) Substrate inoculated with MELRC (SI-MELRC); E) Substrate with biochar inoculated with MEU (SBI-MEU); F) Substrate inoculated with MEU (SI-MEU); G) Substrate with biochar inoculated with TSB (SBI-TSB); and H) Substrate inoculated with TSB (SITSB). The variables analyzed were number of leaves (NF), leaf area (AF), total length (CT), tuber weight (PT), tuber diameter (DT), root length (CR), fresh root mass (MFR), tuber height (HT) and root dry mass (MSR). Data were submitted to analysis of variance (ANOVA) and regression, and significant differences were evaluated by the F test at probability levels of 0.01 and 0.05. The results indicated that treatment D (SI-MELRC) had the greatest positive impact on all variables evaluated, standing out as the best combination for the development of Raphanus sativus L. The use of substrates combined with biochar and microbial inoculation showed promise in the cultivation of Raphanus sativus L. (radish), promoting significant improvements in the growth and development variables evaluated. Among the treatments tested, the substrate inoculated with MELRC (SI-MELRC) stood out, presenting the best results in all variables analyzed. These findings reinforce the potential of biochar as a substrate conditioner and highlight the importance of microbial inoculation to maximize the benefits of this system. Future studies can explore the replicability of the results under field conditions and with other agricultural crops.Keywords: biochar, Raphanus sativus L., radish cultivation, microbial inoculation, substrate conditioner, agricultural production.