Impact of Humic Substances and Marine Algae Extract on Development, Physiological Traits, and Mineral Content of Custard Apple
摘要
The study aimed to investigate the effects of different concentrations of humic acid (1000, 2000, and 3000 ppm) and seaweed extract (1000, 2000, and 3000 ppm) on the growth, physiological traits, and leaf mineral composition of the custard apple cultivar Balanagar. The results derived from this extensive investigation indicated that there was a remarkable and statistically significant enhancement in various growth parameters, including plant height which reached an impressive 3.51 m, North–South spread measuring 3.48 m, East–West spread at 3.49 m, and a leaf area that expanded to 6.42 square centimeters, all of which were observed in the plants treated with the combination of humic acid at 3000 ppm in conjunction with seaweed extract at 1000 ppm; furthermore, it was also documented that the total number of flowers per branch amounted to 246.34, the number of fruits per plant was recorded at 91.33, the minimum proline content was noted to be 8.28 micromoles per gram, total chlorophyll concentration reached 2.48 mg per gram, photosynthetically active radiation (PAR) was found to be 1607.50 micromoles per square meter per second, and the leaf mineral content showed elevated levels with nitrogen at 3.98%, phosphorus at 2.39%, potassium at 2.90%, sulfur at 2.84%, calcium at 2.80%, magnesium at 3.74%, zinc at 30.79 ppm, manganese at 33.42 ppm, copper at 26.80 ppm, iron at 98.00 ppm, and boron at 122.54 ppm, which were all significantly higher in the treatment group receiving humic acid at 3000 ppm combined with seaweed extract at 2000 ppm throughout both experimental years, which were 2022 and 2023.