Morphophysiological performance of Handroanthus impetiginosus seedlings produced in organic substrates

The growing interest in native tree species for commercial reforestation or conservation purposes makes studies on substrate formulations and characteristics for producing quality seedlings extremely important. The study aimed to evaluate the effects of different substrate combinations on the quality and development of seedlings of the native tree species Handroanthus impetiginosus, whose seeds were collected from 15 mother trees, ensuring adequate genetic variability of the plant material. The substrates used in the treatments were: commercial substrate, carbonized rice husk, refrigeration waste, poultry litter, and boiler ash. The parameters evaluated were: plant height - H, stem diameter - SD, total chlorophyll, seedling emergence - SE, germination - G, germination speed index - GSI, mean germination time - MGT, shoot dry mass - SDM, root dry mass - RDM, total dry mass - TDM, lignification index - IL, robustness index - RI and Dickson quality index - DQI. The parameters SE, G, GSI, and MGT did not show significant differences among treatments. Treatment S5 (25% oxisol + 25% refrigeration waste + 25% poultry litter + boiler ash) provided the highest average values for H, SD, SDM, RDM, TDM, RI, and DQI. The substrate composition in treatment S5 resulted in a fertile, stable, and efficient substrate for seedling development, demonstrating its potential as a viable and superior alternative to currently used commercial substrates.