Abstract:

In order to screen suitable substrates for cultivation of banana tissue culture seedlings, research on cultivation substrates using biochar as the main material was carried out. Statistical methods were analyzed using one-way ANOVA. In this study, a series of biochar by volume (2%, 5%, 10%, 20%, 50%) and iron powder were added to coconut coir and then were used to plant the banana tissue culture seedlings. Potting trials were conducted in 2022 at the trial base of the Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences. Factors including the changes of matrix traits, plant growth and development, and NPK nutritional status during the seedling growth were monitored in order to screen out the proportion of biochar added to coconut coir. The results showed that the addition of biochar had no significant effect on most of the properties of coconut bran, but the addition of iron powder significantly reduced the content of the matrix available phosphorus. When the volume ratio of biochar added into coco coir was less than 20%, the dry matter of stems of banana seedlings significantly increased by 3.5%-193.8% and roots of banana seedlings significantly increased by 22.2%-39.8%, and the nitrogen and potassium content of seedlings significantly increased by 5.0%-182.9% (except for B₁₀I) and 7.1%-178.1%, which might indicate that the addition of biochar improved the nitrogen and potassium nutrition of banana tissue culture seedlings. However, adding more than 20% biochar in coconut coir inhibited the growth of banana seedlings though no significant effect on the properties of the substrate was detected. Furthermore, adding iron powder together with biochar into coconut coir greatly reduced the content of available phosphorus in the substrate and thereby inhibited the growth of the plant. In conclusion, the addition of 2%-10% volume ratio of biochar in coconut coir was suitable for the cultivation of banana tissue culture seedlings, and had a broad application prospect.

Key words: coconut coir, biochar, banana tissue culture seedling, culture medium