The present experiment entitled, “Effect of GA3, NAA and Biofertilizers on seed germination and seedling growth of custard apple” was designed with an objective to study the effect of different concentration of PGR and biofertilizers on seed germination and seedling growth of custard apple. The experiment was conducted at the student instructional field and Shed-net House, Department of Horticulture,
School of Agricultural Sciences, G. H. Raisoni University Saikheda, Dist.- Pandhurna (M.P.) during
Rabi Season of Year 2024. The experiment was laid out in RBD (Randomized Block Design) with 11 treatments including control, the detail of experiment are, T
1- Control, T
2- Gibberellic Acid @ 50%, T
3- Gibberellic Acid @ 75%, T
4- Gibberellic Acid @ 100%, T
5- Naphthalene Acetic Acid @ 50%, T
6- Naphthalene Acetic Acid @ 75%, T
7- Naphthalene Acetic Acid @ 100%, T
8- Azatobactor (5 ml/l of water), T
9- Azatobactor (10 ml/l of water), T
10- Azospirillum (5 ml/l of water) and T
11- Azospirillum (10 ml/l of water). The observation on growth characters was recorded under the experiments is days to germination (Days), days to 50% germination (Days), days to 100% germination (Days), height of seedling at 60 DAS, height of seedling (cm) 90 DAS, diameter of seedling (cm) at 60 DAS, diameter of seedling at 90 DAS, fresh weight of shoot at 60 DAS, dry weight of shoot (g) at 60 DAS, fresh weight of shoot at 90 DAS and dry weight of shoot (g) at 90 DAS. The result revealed that the treatment T4 (Gibberellic Acid @ 100 ppm) consistently outperformed all other treatments, producing the earliest seed germination (28.43 days), 50% germination (33.19 days), and full germination (38.30 days), whereas the control (T1) exhibited the most delayed germination (36.02, 40.51, and 47.02 days. Seedling growth parameters were also markedly improved under T4. The maximum height was achieved under this treatment (15.25 cm at 60 DAS and 30.70 cm at 90 DAS), along with the greatest seedling diameter (0.356 cm and 0.515 cm. This treatment further resulted in the highest fresh shoot weights (1.73 g and 2.66 g at 60 and 90 DAS) and dry shoot weights (0.170 g and 0.513 g). Treatments T6 (NAA @ 75 ppm) and T3 (GA₃ @ 75 ppm) followed closely and performed statistically at par with T4 in several parameters, while the control recorded the lowest values across all traits.
